jigga009

It might seem strange for a few reasons which might become apparent shortly. 7 points though - 1) I did not perform the install. I was able to draw this up based on a brief description of the way it was put together. I was not mechanically inclined to the point of getting into the nitty gritty of wiring a fuel system up back then, but I am being forced to do some learning now. There might be a few details missing within the drawing, and I'm quite sure that there are, given that I drew it up based on what I was told over the phone by the shop that did the job from what they can remember of it a few years back. This is also the reason why my initial post might have seemed very confusing and light on technical information. This isn't my expertise; I'm learning as I go. 2) FYI, Bosch 044 fuel pumps or even Weldon fuel pumps for that matter cannot/should not be run via a Pulse width modulation controller. Not like you can with an Aeromotive external pump and their PWM controller. I looked into it years ago before going with the Weldon controller. 3) The Weldon pump controller runs the primary pumps at a reduced speed because of issues relating to fuel heating and vaporlock and other less tangible issues I was experiencing due to my location, and the rest of my setup, and how I use the car, etc. 4) At high load, yes, the primary pumps run unrestricted thanks to the Aux 6 output from the ECU. The secondaries are not controlled by the Weldon controller because they are only needed at high loads/boost to provide additional fuel flow only when needed. They don't need to run at reduced speed because they are off most of the time when puttering around town, and only awake when their flow capabilities are needed at elevated boost levels. 5) Yes, both 044 pumps do in fact have check valves installed at their outlets. 6) I apologize - Aux 6 is an output from the ECU that kicks the Weldon controller to run the primary pumps unrestricted under load conditions. ECU does this just prior to turning on the secondary pumps. 7) I do realize that without knowing all the details on my car, you are very critical of it, and don't hesitate to voice it in this and other threads I have created looking for assistance with curious problems, and that's okay. I'm sure that most people on this forum have a lot more technical experience working on these cars than I do, as this definitely isn't my area of expertise, but I am willing to learn and pick up tools that I need to work on things here and there in my garage. Dealing with these issues that crop up forces me to learn more and more about how things work on it. With that said, it is my hope to leverage some of that knowledge you obviously have in spades in coming up with ideas of things I could check on this setup in order to perhaps figure out why it might not be working as intended, or if there is something that was missing that would make it work as should. I did not arrive at this setup overnight or through some perverse desire to have the most complicated fuel system known to man. It took more iterations of fuel system setup than I care to admit before I had something that not only did the job as far as providing sufficient fuel flow, but also exorcised a few negative characteristics I simply could not tolerate with aftermarket fuel systems that provided the sort of fuel volumes needed to support what the engine setup consists of. Hope this sheds a bit of light on things.

Schematic of the Weldon fuel pump controller: https://www.dropbox.com/s/h1pofregrxrbfiu/IMG_4351.JPG?dl=0 Additional documentation from the literature included with the pump controller: https://www.dropbox.com/s/ep8m6hx1xpx9qwu/IMG_4355.JPG?dl=0 https://www.dropbox.com/s/or3i0rqj1vmnmxu/IMG_4354.JPG?dl=0 Schematic of the car's fuel system to the best of my knowledge. I did not perform the install myself, and just received a brif https://www.dropbox.com/s/keamf8tl9z8oly6/IMG_4357.JPG?dl=0

Pardon my ignorance, but would having things set up the way they are be the cause of what I am experiencing? Could the way I have things set up at the moment would be why I can turn on each half of the fuel system individually, but not turn both halves of the fuel system on to run at the same time? Pumps 1 and 2 (aux 7) are on full time running through a Weldon pump controller, so would it not make sense to send out a 12V signal to run the main pumps when on? Pumps 3 and 4 (aux 1) come on and off, depending on what the load of the car is like, so would it not make sense to send a grounding signal for when the secondary pumps are needed?

Thanks for the response Adam, Couldn't say I know why it is set up that way to be honest. It's that way on my previous V88 ECU as well, and I simply carried all the settings over to my current G4+ when I upgraded last February. Should I try switching it to LOW polarity, to see if that has an effect? I can say that the primary fuel pumps are run through a Weldon Fuel Pump controller. Not sure if this is related? It slows the primary pumps down slightly, and when in boost, ECU kicks them up to full speed and turns the secondary pumps on. Question - Should I not be able to command the fuel pumps on at the same time via PCLink in Test Mode? Or is this a situation where the ECU is only happy to turn on run one output at a time in test mode?

Have a fuel control issue that I was hoping to receive some help or tips with: Fuel system consists of 4 fuel pumps - 2 in tank Walbro 255s, feeding 2 Bosch 044s in line after the surge tank. Ordinarily, the car runs on half of the fuel system, commanding the secondary 044+Walbro on when boost reaches above a certain level. The problem I am having is that the G4+ does not appear to be commanding on the secondary fuel pumps when it should. I detect this in logs because when the ECU thinks it commands on pumps 3+4, fuel pressure does not jump as one would expect, and this problem ends up triggering my engine protection which monitors differential fuel pressure as boost kicks in. Primary fuel 1+2 pumps (i.e Walbro #1 + O44 #1) are installed under "Fuel Pump" under Aux 7, while fuel pumps 3+4 (i.e. Wlabro #2 + 044 #2) are installed as a GP output on Aux 1. I tried testing the fuel pumps under "test mode", and they all work, but only when I test pumps 1+2 OR 3+4 in isolation. I can command on Pumps 1+2 in isolation without issue I cannot command pumps 3+4 in isolation... when I trigger them through Aux 1, all 4 pumps run.. If I turn on Aux 1 and Aux 7 under test mode, Pumps 1+2 stay run, but 3+4 stay asleep. Both halves of the fuel system are triggered off their own relays, so I can disable whichever half of the fuel system by pulling the appropriate one of the two relays. Map on the car is attached. Here is a link to a datalog - Dropbox Link You will see in the datalog that the fuel pressure doesn't actually increase when pumps 3 and 4 are commanded on by the ECU. Not sure if there is something in PCLink that I am missing that would cause the pumps not to be activated by the G4+ while in use, but allow me to activate 1+2 and 3+4 independently but not together. Current Map rev 0.5.pclr

Sorry for the lack of updates.. It wasn't a mechanical issue with the engine after all, although I could not say with 100% certainty what the issue was since it seemed to be resolved after re-installing the map sensor slightly differently compared to before. Map sensor was not reading correctly, but I suspect it was due to a kink in the vacuum hose to it. Following my testing with the Mityvac, I re-installed with new vacuum hose and relocated it so that the vacuum hose was not precariously/tightly angled on its way to the intake manifold as it seemed to be prior, and once I restarted he car, all appeared to be well in the world again. I suspected also that the engine was not actually seeing 6psi sitting at idle because my OEM boost gauge is plumbed independently to the intake manifold, it it never registered positive boost. I now seem to have a fuel pump control-related issue, but I will start a new thread on that one. Thanks to all of you who chimed in

Oh I see what you mean!! I completely forgot that I had the ECU internal logging on, and I did not realize that it was the internal data that I posted for you to see... My bad! Yes, what you are seeing in that area is me testing the system. I could only get up to 20 psi because I purchased the plastic version of the Mityvac, and I did not want to snap the handle while trying to push over 20psi at the map sensor. The device can definitely go higher I suspect, but I'd rather not break it in trying to do so. If I sprung for the metal version, I think I could have easily pushed more air into the system. In hindsight, I think I might return this in exchange for the metal version later. Yes, some of those where the MAP value is changing and the engine is not turning would be me testing the system with both positive and vacuum pressure. And yes, I do recall hitting the throttle briefly while testing as I was trying to make sure that the PCLink was in fact recording what I was doing... by blipping the throttle, I could easily see the TPS graph move on the screen. Sorry about that!

Thanks for your response Stevieturbo I didn't post any logs of me testing with the MityVac. For that part, I simply wrote down what PSI I sent to to the map sensor, and also wrote down what I was seeing on PCLink in response to the pressure going in from the MityVac. Here is the data from testing the map sensor with the MityVac: Key On, 0psi on Mityvac: MAP (psi): 14.1 MGP (psi): 0psi ~5Psi on Mityvac: MAP (psi): 18.1 MBP (psi): 4.1 ~6psi on Mityvac: MAP (psi): 20.5 MGB (psi): 6.4 ~10psi on Mityvac: MAP (psi): 23.2 MGB (psi): 9.1 ~15psi on Mityvac: MAP (psi): 29.6 MGP (psi): 15.5 I tried to go to ~20psi, but the pump would not seem to easily support it, and I did not want to break the handle of the pump.. I typically run a base fuel pressure of 54psi on my setup. Yes, I know that ~43psi is the standard, but I get much better atomization with a little more pressure. Since I have the fuel system to support it, it works for me. The shop that reassembled the engine turned the fuel pressure down from 54psi to 34psi because they had no access to the ECU, and also noticed that the engine was being grossly overfuelled, but would not have been able to know that the reason why the car was running so rich after the cam swap was because the map sensor was telling the ECU that it was in boost. In order to reduce the amount of fuel going to the engine (to run well enough to break in the cams), they had to dial fuel pressure down a bit. They told me about this when I picked the car up from them, and they were sure that everything from a mechanical perspective on their part had been done correctly. They did not want to get into the ECU to start probing things there since they did not tune the car. The first set of logs were from when my tuner connected remotely trying to see if there was anything obvious that could be ascertained. He noticed that the ECU was sampling fuelling values from the wrong part of the map, and we needed to figure out why that was. I may have given some throttle here and there to see how the engine reacted. On his instruction, I had a cursory look at the map sensor wiring and the like for anything odd, but did not find anything at the time. Tuner then suggested picking up a MityVac to test the map sensor to see if it is working correctly. It was at a later point in the day that I ran testing with the MityVac, and everything looked to be in line with what it should have been. I reported this to the tuner. Next thing to check was the ignition timing to ensure that the ECU was running the timing we thought it was running. He also thought that there should be no reason to check this if the crank trigger had not been touched, but with what we were seeing initially, we had to run through all options methodically to rule things out. That is what I was going to check yesterday. I disconnected the Mityvac, trimmed a little bit of vacuum hose off the map sensor that I had used to attach the Mityvac, reconnected said vacuum hose to the intake manifold and then went to start the car for the base ignition test. Once started, I realized that the ECU was now sampling from what looked to be the correct area of the map again. Through all of this though, the MAP and MGB always matched on PCLink when the engine was off and key on. I may have had a slight kink in the vacuum line connection to the intake manifold, given the way everything is packaged, as well as the vacuum hose being a bit weathered (i.e. hard) so I will be re-plumbing the map sensor to the manifold with fresh hose. The kink may not have been bad enough to show up in readings when the engine was off, but with it on, was causing the map sensor to give off erroneous readings.

Cant see on your log since it doesn't include everything, but I have a few suggestions: - Have a look to see what your fuel trim is doing when the AC compressor kicks in. I know there is a trim that can increase fuel PW in response to the compressor getting commanded on. If it is coming on, it might make the engine a little unhappy, depending on how large the trim is. It's Under the Idle Load Trims. You are looking for AC Trim. Ensure it is zeroed out, and see if that helps. - Alternatively, you could set up your fan control if you have not already to ensure that only one fan comes on at a time (staggered), thus, ensuring that the current draw of 2 fans coming on at the same time doesn't upset the engine too much. - Alternatively, under idle speed control, you can adjust "engine fan step" in order to keep the RPM a bit higher when the fans are running. That way the electrical load of the fans does not cause the engine to die. - Adjust AC Step as well to give a bit more air to the engine when the compressor is getting commanded on. - Alternatively, perhaps the gain of your closed loop idle control is not high enough?.

Update... Just checked the base timing, and it is spot on the money when locked to 10 degrees with the PCLink. The other odd thing: Not sure if the MityVac did something positive to the map sensor last night, but when I fired up the engine just now to check the ignition timing, I noticed that it is no longer thinking that it is in boost while at idle. It actually references from the vacuum section of the ECU map again. Here are a couple of logs... should have been a single log, but i kept getting excited about things and kept disconnecting the ECU instead of saving the log. https://www.dropbox.com/s/tvtwel2wx4n3tig/log 2018-12-24 - log 2.llg?dl=0 https://www.dropbox.com/s/1uf6m7nmo565hl5/Log 2018-12-24 4%3B28%3B39 pm.llg?dl=0

Correct... Map sensor tests out as I would expect it to... Both in vacuum and with postive pressure when read via PCLink when tested with the Mityvac device. I'm about to go test out the ignition timing on the car. Never done this before, so trying to read up on the procedure. The first log has the base pressure set at 34psi. For all others, it was bumped up to 54 psi, which is where my tuner prefers it to be set. The shop that performed the install actually race Subaru's professionally, and were 100% sure everything was installed to the book. With that said, I am attempting to check what I can of the car in my garage. Unfortunately, I don't have a scope of the car from before with the old cams in place. My tuner was able to remotely log in and determined that the ECU definitely was not dealing with trigger errors... Should changing camshafts require that one perform an ignition base timing test again on the engine? Sorry, no compression test. I don't have a tester at home here, and the cam swap was literally just accomplished a couple of weeks ago. It has only been idled in order to break the cams in. Have not been able to drive the car on the road given what it is doing at the moment.

Today's riddle is as follows.. A Subaru application...I just had some new cams installed into my engine, replacing an older set of cams that suffered a lobe failure on the right head intake side. With the new set of cams installed, engine fires up just fine, but noticing that the engine runs super rich. Richer than one would expect, given that the cam specs are similar to the outgoing cams. Rich enough that the ECU cannot compensate with closed loop idle. Once I looked at the fuel map to see where the ECU was operating, I quickly realize that the ECU thinks the engine is in boost (about 6psi), and AFR's are sitting in the 11's while the engine idles away. Things I have tried: - Checked for vacuum leaks. Boost-leak tested the intercooler plumbing up to 35psi, and no leaks. - Checked the MAP sensor - purchased a Mityvac hand vacuum/pressure tester and the readings on the gauge of the meter align with what the G4+ Xtreme is seeing. - Checked to ensure that all cylinders are receiving spark. All are, and in the correct order, and firing in the correct order. The engine has no issues starting up, but simply appears to be running off the wrong part of the fuel map once running. - Cam timing came to mind, but the thing here is that timing is non-adjustable on my setup, and there are no cam gears to adjust. I did remove a set of Kelford non-avcs cams and GSC AVCS cams of similar lift and duration went back in (but th AVCS holes were all plugged up, and standard non-avcs cam gears used). With that said, I can't seem to figure out what to look at next. Engine builder/Subaru race shop swears up and down that everything went back together correctly, and they also noticed that it was running differently on engine start up. Since they had no access to the ECU, they resorted to turning down fuel pressure in from 54psi base to 34 psi base order to get it to idle. - We have confirmed that the ECU is not picking up any triggering errors. Other possibilities: - Cam timing - the cams that were in there before were non-avcs cams being used in JDM heads triggered exclusively off the Subaru LF intake cam gear and sensor. The new cams that went in are GSC AVCS cams with AVCS holes plugged up, and triggered again off the Subaru cam gear. Advertised cam specs are within spitting distance of each other. Not different enough to cause the car to run as it is right now. I will be checking the base timing of the engine with a timing light shortly, and will report back. In the meantime, here are logs and map: Logs: https://www.dropbox.com/s/2uffohc3y47fg0g/Mike 1%3B21%3B26 pm.llg?dl=0 https://www.dropbox.com/s/btn3zjo6i376w1v/Log 2018 - 12-22%3B log 1 of 3.llg?dl=0 https://www.dropbox.com/s/vh1nflx87b97kn4/Log 2018 - 12-22%3B Log 2 of 3.llg?dl=0 https://www.dropbox.com/s/r4sikntahofml85/Log 2018-12-22 10%3B21%3B55 pm.llg?dl=0 Map: https://www.dropbox.com/s/sei4r0aepxh0rrv/LINKECU FORUM TestMAP - 1.99904.pclr?dl=0 If anyone has any other ideas, or notices anything from the logs and the map, I'd be grateful for your suggestions. Thanks again, and Happy Holidays!

I use MSD's coil and wires, but that's it.

Stevieturbo, thanks for your response! I don't believe it is an alternator issue, as logs showed system voltage to be utterly normal all the way to the end. I'm not ruling out an alternator issue though, but unless the log is telling me porkies, the log shows that the alternator was working, with voltage in the 13.7-13.8V range all the way to the end. In addition, I do have warnings on my dash set to warn me if and when voltage drops below charging voltage or above normal voltages. Nothing from what I can see in the log was out of the ordinary. Sadly, the shop I visited today with the alternator could only test it if it came out of a specific vehicle... Since it is not a normal production alternator off a specific vehicle, they were unable to program their computer with the details on the alternator in order to run the test. They did not believe though that it sounds like an alternator failure, given that data logs showed that it was charging all the way to the end. They thought I would notice other electrical-related issues such as issues with the radio. My battery did pass testing with flying colours though! The whole CDI vs IGN1A inductive coil debate is old and about as divisive as talking politics and religion on a first date. I have my reasons for running a CDI setup, and I am well-aware of the capabilities of the stock Subaru COP, and have heard the arguments from those who are pro-IGN1A as well. I don't think anyone is grossly wrong at all. Both solutions have their pluses and minuses. All I can say is that I'm not one to complicate things any more than I need to, and think long and hard before leaving the safety and reliability of OEM for anything aftermarket. Not to be cryptic, but putting one and one together, you already have an idea of the limits of the Subaru COP system, and I've already described what I experienced when I found that I was reaching the limits of the Subaru COP setup, so one might deduce that I am dealing with a slightly more serious setup than average. You are correct about the use of crimping in those industries I learned about the space vehicle use of crimping connections from a former NASA technician who chimed in on a different forum I came upon, weighing in on the debate. In addition, all the videos I saw online made crimping look even easier than soldering, and I was feeling lazy that day also.. I'll freely admit though that I have been soldering for much longer than I have been crimping :s Regardless, my badly crimped connections were not the cause this issue I am seeing, as I tried starting the car again today. I am looking into other things now such as engine grounding connections, which might affect both CDI systems and also explain why it seems as if the starter motor is rather slow, even when powered with a fully charged AGM battery producing over 1000CCA. Even if grounding is found not to be the cause either, at least it gives me a chance to spruce those areas of the car up that I have not touched in a while.

As mentioned earlier, there is a reason why I had to go with a CDI setup over the stock COP; I was bumping into its limits, and the only way forwards in my situation was to switch to a CDI system. I would have been all too happy to stick with the OEM COP if its limits were a bit higher, and the transient demands it was putting on my electrical system (even with a 160amp alternator) was not dragging the system voltage dangerously low. Lord knows I prefer the drivability associated with the stock COP over CDI, but the COP was showing signs of not being appropriate at the power levels being run. I do agree though that they can be quite annoying from a reliability perspective, and with the longer duration of each spark with an inductive ignition system, low-down drivability/torque is actually better imo with a COP setup. With that said, CDI systems do bring certain benefits that are hard to ignore once you have outstayed your welcome on the stock Subaru COP system, and it isn't as if people don't have issues with stock coils acting up either. I do hear that Nissan R35 GTR coils might be a lot more capable than anything Subaru has though, so perhaps somehow retrofitting those coils might be a solution for reliability while being able to light off the plugs. Mini-update for the day: I didn't have too much time today, but I was able to dismantle the old crimp connections I made a couple of weeks ago as per CJ's suggestion and properly solder on some eyelets instead. I unfortunately did not take any pictures as I went, but after looking online at proper crimping examples and comparing them to what I thought was good enough, I have to admit that I likely won't bother crimping anything again. I should have soldered these connections, but I was too lazy at the time to bust out my soldering station. The other thing I noticed is that 2 weeks after installing the crimp connections in the first place, all 3 wires (main fuse box 12V+, CDI box #1 12V+, and CDI box #2 12V+) were developing corrosion (green residue on the exposed copper strands within the crimps). I could not see this before now due to the plastic sheath on the eyelet ring terminals that covers everything behind the ring. I cut off the affected wire and exposed fresh sections to solder into eyelets, cleaned them with isopropyl alcohol then tinned them up and used flux to allow for good solder flow into the eyelets. Everything has adhesive heat shrink tubing to keep moisture out. One last thing I will do tomorrow before attempting to firing it up is to apply some Stabilant 22a to the eyelet connections within their fuse box. I should be able to try firing the car up tomorrow. It's a bit late in the evening right now, and the car is rather loud.

Hi CJ, thanks for your response! And I am thinking that your theory might be on the money...I'll explain. The battery in my car has been relocated to the boot, since there is no room in the engine bay these days. I have a 2AWG wire going from the battery positive to the starter motor, and then another 2 AWG line from the starter motor to a "2 AWG in/2AWG out" distribution block with 150A inline fuse mounted on the side of the engine bay just underneath the main fuse/relay box in the engine bay. Coming out of that distribution block were 2 10AWG wires that feed each of the CDI boxes and an 8AWG wire that feeds the main OEM fuse box in the engine bay. All 3 wires were sort of scrunched together and inserted into the outlet of the distribution block. The car worked fine like this, but I wasn't completely happy with the solution since it always looked like the conglomeration of wires was always on the verge of popping out and looked to be full of dirt. The car ran around like this since it was put together a few years ago, with CDI boxes going bad every once in a while, but as I maintained before, i had always been able to fire all plugs at once in order to see which box had an issue. I was happy with the function of the car, but never really liked how the shop sort of twisted all 3 wires together and shoved them into the outlet of the distribution block. A couple of weeks ago I made what I thought was a slight change with the intent of cleaning things up a little bit - I purchased one of these: https://www.bluesea.com/products/5045/ST_Blade_Compact_Fuse_Blocks_-_4_Circuits And then removed the old power distribution block with integrated 150a fuse and connected the 2AWG wire from the boot of the car to the bottom post of the new fuse block pictured in the link using a 2 AWG set screw ring terminal, and then crimped some eyelets onto the 2 10 AWG wires that fed each CDI box, and one on the 8AWG wire that went to the main OEM fuse/relay box. I then installed all 3 wires onto the new fuse box. The fuse box was then mounted just underneath the OEM fuse/relay box where the old "2AWG in/2AWG out" distribution block was located before. Since the wire going to the main fuse box was 8AWG, I used a 40Amp fuse for that, and for the CDI circuits, they each received 30A fuses since they were 10AWG wires. This matched the 30A rating of the in-line fuses the CDI 12V power wire came with. I did crimp eyelets onto each of these wires, and while the crimps did feel secure when I made them a few weeks ago, I did notice on Sunday that they did not seem as tight when I was busy scrambling around trying to figure out what was going on with the car on the side of the highway. It did not occur to me though that they might be loose to the point of causing such an issue though, but I may have been wrong. I typically solder all of my connections (and all of the other connections mated the CDI boxes to the car when installed professionally were soldered), but for some reason I thought I would give crimping wires a go, since it seems to be an accepted way of making an electrical connection. So in essence, I introduced crimped connections to a setup that used soldering for all previously existing connections. It might be that the vibration the car has undergone within the past couple of weeks of use shook the connections I made loose. As you theorized, both CDI boxes receive their 12V power from the battery via the crimped eyelet connection to the fusebox in the link above, and the crimp connection may not be the best, I freely admit. The CDI boxes also receive a switched 12V source, and I was able to confirm with a testlight that each box was connected (soldered) to switched 12V supply. All other inputs from the ECU were tested and found present and functional. The only connection I forgot to scrutinize were the crimped connections I introduced to the system, which as you theorized, provide the main power to the boxes. They are the only non-soldered connections in the entire system, and also the latest additions to what was a working system. :/ I'll break out the soldering station and get them soldered tomorrow morning Thanks for your suggestion!!

Adam, the CDI system is in fact able to fire both channels simultaneously, or close to simultaneously (in cases where the leading and trailing spark plugs fire close together) as each channel has its own storage capacitor... I found this information in the instruction manual.

I'm guessing this is what my tuner was referring to when he mentioned that I would have to make some adjustments within the map if I decided to switch back to the standard Subaru ignition setup; dwell settings... I was under the impression though that dwell settings are a little redundant with a CDI setup though? Since the module itself controls how long it charges for?

Yeh mine is set at 3.0ms all the way from 10-16v at all RPM levels.

Hmm... But is that with a CDI ignition system though or with the stock COP inductive setup though? I am curious as to whether I could actually allow my CDI boxes to run cooler by running a smaller dwell that is closer to zero without throwing off the map.... hmm...

Looking through the manual of my CDI, dwell appears to be set properly at a "non-zero value", and without change with different voltage levels within the ECU tables, so I would *guess* that as long as the value is not zero, the CDI could care less what value it is? I hope someone with more knowledge can chime in here and bless me with some knowledge

Good point regarding the CDI boxes. I will check the CDI manual to see if there is anything outlined in there regarding input over-voltage protections. With that said, the log from the ECU shows that system voltage was as high as 13.9V shortly after I fired the car up at the start of the trip, and was at 13.7V about 48 mins later when things started shutting down. I would know immediately if my system voltage goes above about 14.8V through my dash, and no warnings came in, confirmed by the log I have. I'm honestly not sure whether the dwell setting on the ECU could be making them overheat. You make a really good point though, and I'm going to have to look into a bit deeper. Thanks very much for this. Looking at the dwell table on my car, at 14V it is set for 3.0ms. I'll admit that dwell is an aspect that I have not read up on, so I'm unsure as to what this means in the context of my particular setup. I will look into it though.

Hi Neil, thanks for your response! You must be watching me because I was just starting to look through the manual of the ECU to find any circumstances under which it would shut the engine down aside from rev limiters and the like! Voltage was around 13.5V when things started going off-line. Yes, on mine, the exhaust comes down right where the ECU lives. In addition, the size of my downpipe is such that it comes within very close proximity to the firewall of the car. It is 4 inches in diameter, if that gives you a hint. Battery voltage was in the mid 13's V range when it shut down. I have warnings for over-voltage on my AIM dash display to warn me of anything out of the usual with respect to voltage. Looking through the log of the event, it really does look as if nothing is wrong, and someone just started turning off off the spark plugs while the car was in motion. I was stumped, but then only now just recalled that in previous summers when I first got my V88 years ago, I had in fact experienced something similar, and I quickly learned to use AC when running around for long periods of time in order to sidestep the issue.

Something that occurred to me today while poking through my utterly normal log of the event was something that I used to experience with my old Vipec V88 during summer months under very similar circumstances to the day the car stopped running with the G4+.. During summer months with my V88, it had a habit of shutting down the car on hot summer days (usually this time of the year) if I drove for long periods of time without cooling the interior of the car with AC or with windows down. Once I let the car cool sit and off for a period of time, it would start up again like nothing ever happened, and then start shutting cylinders down again if I drove for a while again without AC or without windows down. I was able to deduce back then that the ECU might have been getting too warm underneath the passenger footwell where there is no airflow and the downpipe of my turbo passes nearby in the engine bay. I had not experienced the same thing with the G4+ since I only picked it up about 6 months ago during winter months, but this is my first summer running this ECU and when I think about it, the conditions seem a bit too similar for comfort, with ambient temps in the 28 degrees C range with clear skies on that particular day. I imagine that it was even hotter in the interior of the car since the windows were not open either. I checked my log, and I was running the car on the highway for about 99% of my trip without the AC on. I don't drive with windows down on the highway either due to wind noise, and it lets me better hear if there is a change in engine noise so I know to shut things down myself. When the engine stopped running this time, I had felt uncomfortable enough in the car to turn the AC on to the first fan speed, and precisely about 1 minute later, the engine itself started shutting down. I know that the ECU's are burned in at the factory and the like at much higher temps at the factory, which is probably why everything works like normal after giving everything a chance to cool off, but this was definitely something I experienced consistently with my old V88 in the passenger footwell during summer months, and perhaps the G4+ is the same given that it is located in the same position in the car? I can't say what temps the old V88 logged when it used to shut down because I was never logging when it happened, but I do remember that it was at ambient temps similar to what they were when I experienced my issue this time also, and the mechanical setup of the car is identical between the ECUs. It might explain why my logs look utterly normal prior to the engine shut-down event. I'll be installing another set of plugs into the car and attempting to start it a little later today if I have time or tomorrow, so it should be interesting to see if it runs, given that there have been zero mechanical changes (aside from plugs) on the car between when it stopped working and when I fire it up again. I'll keep everyone posted.

Thanks for the response Adam, I'm honestly at a bit of a loss as to why the thing stopped in the first place if the Link is firing each plug sequentially. I definitely recall you making the comment about not thinking that many CDIs can fire all channels simultaneously, but I now better understand what you meant. To partly answer your question (because it definitely came up during the conversation with the manufacturer yesterday), the CDI does in fact have an independent capacitor for each channel. It is for this reason they are sure that their boxes work properly since I can command each channel on in isolation, and each channel definitely fires the plug (sequentially when cranking the engine and through the ECU's test mode). My plan for today includes installing the plugs into the engine heads and actually see if it runs with the G4+. If not, I will try the same on the stock ECU to see what happens. As far as why the engine stopped in the first place, I am not sure...If you look at the log I included of the event, you would see that I was literally cruising at speed when all of a sudden it seemed to shut down by itself. The only reason why I initially suspected a CDI box issue is because that is the typical failure mode I've experienced with them... You would be driving, when all of a sudden you drop one or more cylinders and the car can no longer carry on at speed. Luckily, I was data logging all channels directly to my laptop at the time it happened, so I do have a record of what the ECU was doing and seeing on all channels, but I'll be the first to admit that I am not skilled enough to see anything that is glaringly wrong in the log. I have included the log in my second post in case something jumps out at you? - Datalog from when engine stopped running I'm going to follow up with them today regarding the second part of your question - whether the CDI can actually fire both channels simultaneously. My guess after seeing what I've seen so far with the existing CDI's that were in the car when the issue hit, and when I switched in my spare box is that it cannot (just as you predicted), but I will wait and see what they say about that part. I will say though that they were very curious initially as to how exactly I was triggering the CDI to fire all plugs at the same time. It was when I explained that it was through a standalone ignition test mode and which standalone it was that the gears started to turn in their heads. Even then, they wanted to know exactly how the ignition test mode on the G4+ worked..something I could not answer, except to say that it signals a firing at a frequency of 10Hz to the CDI box which I have confirmed is definitely reaching the box on both channels. I will let you know what they say with respect to being able to fire both channels simultaneously. Hi Neil, thanks for your response. It is a new-age Subaru bugeye car, but the coil on plugs are long-gone. They had to be pulled because the stock ignition system was causing some rather large transient voltage drops in the car at elevated power levels. Switching ignition systems was the only way to stop this happening. The stock ECU does have the ability to run the engine with the CDI system though, but I have to run the CDI's in their non-restriking mode.