jigga009

Cj, thanks very much for the suggestion.. I'll try this tomorrow and see what happens. I should be able to switch the wires on each bank around, but won't be able to switch between banks without some major rewiring. Another frustrating and confusing mini update from today: I was in touch today some more with the manufacturer of the CDI i'm using in order to obtain an RMA#, and a different tech wanted me to describe everything from the top again. While he was more than willing to give me an RMA to send them in, he was confident that there is something different about the way the G4+ calls for individual cylinder fire within its test mode compared to what it does when you actually run the car, or when you turn on all channels. I asked why it was they believed this, and they stated that it is because if each channel works in isolation (which they do), the CDI is fine. They mentioned that once I figure that out, I would know why it is that it "appears" that each CDI is not firing off both of their respective channels. To test, they had me revert to the stock ECU while keeping the CDI boxes in place and crank the engine to see whether I am still only getting one cylinder on each bank firing, and lo and behold, during cranking on the stock ECU, all 4 plugs were firing. I was stunned. I then tried the exact same thing on the G4+, actually cranking the engine and observing the plugs, and it also fired all 4 spark plugs sequentially just as on the stock ECU. Now that I established that both the stock ECU and the G4+ were both capable of firing all individual spark plugs sequentially through the same CDI boxes that were on the car when it stopped, I decided to try the G4+'s ignition mode again in order to see what happens, and sure enough, as the manufacturer of the CDI guessed, something changed. It looked just as it looked before - as if the engine was again not running on 4 spark plugs. I could command on each individual plug in isolation just fine with a nice spark, but could not observe a spark in all 4 plugs if I turned all cylinders on and sat back to watch.

New update for those watching in the background! I ran further tests using my new-found toy, the LED test light (Thanks Adam!!). After back-probing the harness of the CDI boxes that serve the left and right banks of the engine, I was able to determine that the signal to fire the coils is in fact reaching the CDI boxes from the ECU, so given the following bits of info that I have accumulated so far: - ECU is definitely firing its ignition outputs (confirmed by back-probing at the ECU itself) - I am able to command on each spark plug by itself (suggesting that the wiring pathway between the ECU and the CDI boxes is fine) -Signal from the ECU is reaching the CDI boxes on both sides of the engine (I back-probed the connector going into each box for the signal from the ECU, and the light blinked at the roughly 10Hz that it did when I back-probed at the ECU connector inside the car.) - Coils test in spec - Spark plug wires test in spec - I used new spark plugs just to ensure that spark plugs are not the cause of the issues I am experiencing. - CDI boxes are in fact receiving a full 12.87V from my battery - I can't actually measure the output from the CDI to the coils since it is somewhere in the 500V range, but I can observe whether a spark is jumping at the plug though. I'd conclude that as unlikely as it seems, both the CDI boxes are at fault. There is a bit of a plot twist to all of this though which made the scenario very confusing from the start: 1) I swapped what I thought was a known good box into the car, and the problem persisted, leading me to prematurely rule out issues with the CDI bo. After back-probing this spare box and observing that the ECU is in fact commanding it to fire, AND that it is receiving appropriate voltage from the car, it would seem that my spare CDI box was a dud also. 2) Both boxes on the car appeared to have failed in similar manners, but to different extents... Box 1 can fire each cylinder individually, but when placed on the driver's side of the car, can only fire "1.5" plugs (fires one strongly, and the other one weakly). When on the passenger side it can only fire one cylinder when both cylinders are commanded to fire. Box 2 can fire each cylinder individually, but when placed on the driver's side of the car, can only fire 1 plug when both are commanded on. When on the passenger side of the car, it can only fire one plug when both plugs are commanded to fire. My "spare" box appears to have the same issue - can fire each plug on its own, but only one plug out of two when commanded to fire them both. I suspect that in essence, I had been running on 1.5 cylinders on one side of the engine and the full 2 cylinders on the other side for a long time without noticing much loss in power, and never really noticed it until the box that was running at full strength failed and dropped down to 1 cylinder, dropping me down to 2.5 cylinders out of 4, which I could definitely notice, and caused the car to lose the ability to maintain speed. If there is anything that anyone thinks I should check in addition that could change my conclusions, I'd love your suggestions.

Thanks for the suggestion! I tried this just now but still does the same thing, so maybe not a grounding issue after all? :(

Ok new day and a quick update for all who have been advising me so far - I've been able to rule out the ECU. Adam was gracious enough to talk me through the process of using a test light on the ignition outputs of the ECU. I purchased one this morning, and sure enough, all ignition outputs were firing when commanded to do so via the software. Even when all were commanded on at the same time, I got a positive flashing LED on my tool when I probed the 4 ignition outputs. So back to the drawing board I guess... I'm beginning to suspect something more general.. such as a grounding issue of some kind that happens to be manifesting itself in the ignition system and possibly other systems in the car that I did not noticed yet. I'll do some more poking around and check back.

Slight update: I called the manufacturer of the CDI boxes on the car just to have a thought experiment with them regarding the particular scenario I have, and their lead tech mentioned that he had never seen such a failure before relating directly to a car running 2 CDI boxes in parallel before. They could see perhaps one CDI box failing (in which case only one bank of cylinders would be affected), but not two going out at the exact same time. In addition, switching in my spare box to test and coming up with the same results as well as being able to fire each channel on their CDI boxes independently was enough for them to rule out the CDI boxes at this time. For them, it has to be an issue upstream from the CDI boxes that is causing this. They mentioned that all the CDI is doing in the car is amplifying whatever signal that it receives directly from the ECU, so if it is that I am able to command each spark plug on individually through the ECU, it would suggest to them that the wiring between the CDI and the ECU is intact and functional, but if I am unable to fire all 4 plugs at the same time, I might want to take a closer look at the source for the ignition signal. They mentioned that on my particular setup, if a CDI box failed on my car, I would be seeing symptoms on one bank of cylinders only (i.e. the driver's or passenger's side of the engine), since I have separate boxes for each bank, and that switching in a known good CDI box would confirm and fix the issue (which it has done in the past when I've experienced a CDI box fail).

In an attempt to take power supply issues out of the equation, I fully charged the battery last night as well as hooked up a power supply to the car, disconnected the relays to my fuel system (since the pumps present an electrical load when key is turned to the ON position) and ran the testing again today. Same results as above

lol I was channeling my inner MacGyver there! Thanks for the roadside tips yesterday; much appreciated! Got the car taken home on a flatbed late last night and performed some more repeated testing today once I got my head back on straight and more relaxed. I was also now able to properly back-probe the ECU using a more appropriate probe repeatedly in order to gain some meaningful information. Here is what I've been able to find out so far today: Each of the ignition outputs of the ECU is putting out a frequency of 3.7khz regardless of whether the ECU was commanding the output to fire or not. This was the case with all 4 ignition outputs. As soon as the key is set to the ON position and the ECU boots up, all four ignition outputs in use show 3.7khz. If I turn on individual cylinders through the ignition test on the ECU, each output continues to output at a frequency of 3.7kHz. If I turn the car off (along with the ECU), the frequency from each ignition output drops to zero. This was the case also after disconnecting the ignition boxes from the equation. Each back probe probe sat at 3.7khz as long as the ECU was powered up, regardless of whether it was commanding a spark plug into action. I was also able to better observe what is going on in th engine bay: When Ignition output 1 only is commanded on from the ECU, spark plug #1 (bank 1) fires vigorously. When Ignition output 2 only is commanded on from the ECU, spark plug #2 (bank 2) fires vigorously. When Ignition output 3 only is commanded on from the ECU, spark plug #3 (bank 1) fires vigorously. When Ignition output 4 only is commanded on from the ECU, spark plug #4 (bank 2) fires vigorously. When Ignition output 1 and 3 (cylinder bank 1) are commanded on together, Cylinder 1 does not fire at all, and cylinder 3 fires. When Ignition output 2 and 4 (cylinder bank 2) are commanded on together, Cylinder 2 fires sporadically, and cylinder 4 fires more strongly. When all 4 ignition outputs are commanded on at the same time, cylinder 1 [bank 1] spark plug is dead, Cylinder 3 [bank 1] spark plug is firing strongly, Cylinder 4 [bank 2] spark plug is firing strongly, and cylinder 2 [bank 2] spark plug is firing sporadically. Adam mentioned that in his experience, some CDI boxes are not happy firing both channels at the same time, but I have always been able to turn on all 4 ignition outputs at the same time from the ECU and watch all 4 plugs sparking vigorously at the same time in order to diagnose CDI box failures - I would just pull all 4 plugs and ground them against the intake manifold turn on all 4 ignition outputs with the spark plugs out of the cylinders, then hop out of the car and see which side of the engine is asleep. I switched a known good CDI box that I carry as a spare into the left and then into the right side banks, and the exact same phenomenon as above occurred, so I'm quite sure that this isn't a CDI box issue. I checked the resistance on the primary and secondary sides of the ignition coils in the engine bay, and all were in spec according to MSD, so I'm quite sure that this isn't a coil issue. I checked for resistance with my plug leads, and again, all were in spec according to MSD, so I'm quite sure that this isn't a spark plug wire issue. I tried performing the above experiment with a new set of BKR7e plugs, and the exact same phenomenon occurred, so I'm quite sure that this isn't a spark plug issue. As for wiring issue -- I don't want to cloud people's thoughts, but since I can turn on individual cylinders at will, and they spark vigorously as long as they are the only cylinders turned on, would that not suggest that the wiring is fine? Fortunately, I was actually data-logging the car when it decided that it was time to go to sleep on the highway. You would need to fast forward to the end the datalog for the fun bit: Dropbox link to datalog

Odd title, but let me explain what happened... crusing along a highway in my Subaru when all of a sudden I could detect a misfire in progress. It felt as if the car was no longer running on 4 cylinders. upon diagnosis on the side of the road, I came to the realization that when I pull all 4 spark plugs, cylinders 1 and 3 do not spark together during an ignition test for cylinders 1 and 3. If on the other hand I test just cylinder 1 or just cylinder 3, the spark plugs spark. Car runs a pair of 2 channel CDI ignition boxes for each side of the engine. I have tried swapping a known good CDI box in on the side of the engine with cylinders 1 and 3, and the same thing happens. I have been able to rule out issues with the ignition coils themselves since I can get cylinders 1 and 3 to fire in individual tests, but not together. I think I have also been able to rule out an issue with the CDI box since I swapped a known good box in and same thing happens. Does this sound like an issue with the ecu itself? if anyone has any ideas, I would be grateful. I do apologize if the message is a little disjointed, as I’m posting from the side of a major highway on my cell phone:(

Tried these settings on Testmap 2.2... Less popping and banging going on, but still some. I took the car out on a drive, and noticed popping and banging while on the move at low throttle positions, and the car just overall not wanting to do much when in vacuum, and then there is the sound of what seems like a lean misfire that I keep detecting, almost as if the engine suddenly switches to running on 2 cylinders or something. It just seems to be running rough overall. It still doesn't really want to move from a stop again unless I try to bypass that area of the map. Tuning Question - What would increasing resolution in the vacuum section do for the way the car runs? There is a second fuel table in the map as well.... will this not have to be reworked as well like the main fuel table? Link: https://www.dropbox.com/sh/xxmfhkbg5sgoslo/AABErJ0boXSHog5rWSdkCp2Sa?dl=0 Thanks

ClintBHP - tried the map, and it still pops and bangs while warming up...Not as badly as last time, but it is still definitely doing it. This time the log includes the entire cold start. Didn't go for a drive this time as it was still hesitating as I tried to move the car. Gentle free-revving at idle isn't occurring cleanly, unless I really put my foot in it to bypass areas of the fuel map that were changed. It overall sounds like it is running lean misfiring. Link: https://www.dropbox.com/sh/ptk7wnzgyhxz8vn/AAAsLQt9W4KrHoJpChB35uX6a?dl=0 Tuning Question - What was the purpose behind us rescaling the vacuum section of the fuel map?

Carried out these changes! The engine did not appear too happy with them, as there was a lot of popping out of the exhaust almost immediately after I started the engine. It actually almost stalled out after the initial start, but caught itself. The events were such that I felt the need to take a log a few seconds into the cold start routine, as can be seen in Log 1. This was a few seconds after initially starting the engine. I also found that the engine was very choppy and did not want to pull away from a traffic light as it would before we altered the axis of the fuel table initially. Almost as if it was too lean. I noticed this a little bit yesteray driving the car with the altered fuel map axes, and noticed it even more with the new fuel settings. This can be reflected in the logs as well, as I wanted to show what it was like driving around. I would say that low throttle driveability (i.e. puttering around out of vacuum) was a bit easier before we changed the scaling of the vaccum section of the fuel map. Perhaps it is something with how the ECU interpolated values after the change OR the tuner found the need to have the initial scaling as was because it improved drivability within the vacuum section of the map? I'm no tuner, so just guessing here and going off my 'before and after' driving observations. Once up to temp, I'm not sure if the idle was any different from what it was on the previous map revision. I didn't really try turning anything on this time, as it seemed that the new driving behavior was more the star of the show than anything else. Log 1 - started just after initial start when I noticed the exhaust was popping and banging, Log 2 - wanted to display what happened when I went to take off from a stop. A lot of sputtering unless I gave a lot more throttle and slipped the clutch more. Log 3 - idle Here are the logs and map: https://www.dropbox.com/sh/6m0ts1ufjwm8qtm/AAAQrDzwcuxSUPaJMYrGwkv_a?dl=0 Thanks again for the time you've taken to help me fine-tune my map, I'm very appreciative!

Map sensor works fine, as we tried it on other cars, but the cams in this engine in particular are such that they cause the map signal to bounce about a lot when the sensor is directly bolted on. No smoke test this time... I have done these in the past, but my issue with them is that unless you have the ability to pressurize the plumbing, you don't see any leaks unless they are gaping leaks that you can drive a car through. I find that using pressure test works better with soapy water, as I can hold a certain PSI in the system using an air compressor (e.g. 25psi), and then spray soapy water at all vacuum hoses, intercooler couplers, joints - basically anywhere air could possibly be leaking between the turbo compressor outlet and the heads of the engine, and look for bubbles to start growing in areas where there are leaks. I have found this to be a reliable method for checking for boost leaks in the plumbing, especially up to the boost pressure that the plumbing will see at full boost. Sadly, it involves renting a decent size air compressor from the hardware store, but it is worth it imo. ClintBHP - Performed the changes you mentioned, and took a log: I did notice that since correcting the base fuel pressure and making the changes to the closed loop lambda fuel trim limits you mentioned, the ECU will always trim the AFR's back to around target whenever I turn stuff on. Glad to see that happening https://www.dropbox.com/sh/oz34qbcovkx0jk7/AAAElv6xBm6QmXvw9jVO48Gxa?dl=0 Please let me know what you think

Yes, cams are set up properly. They are just a lot more radical than what people normally run on the street, and the vacuum at idle is telling. We found out years ago that connecting the map sensor directly to the intake manifold on this engine setup resulted a very turbulent map signal. A short section of vacuum hose had to be used to get a more stable signal. It does share a vacuum source with the Aeromotive fuel pressure regulator. As mentioned earlier though, there are no leaks in the system. After doing some digging into other setups running similarly radical cams (i.e. the specialist's shop car's race engine) the vacuum readings appear to be right in line. It is also in line with what it produced on its first refresh by a different specialist shop.

Yes, map sensor was calibrated via the drop down menu. It was within spec all along. I did have a pretty large boost leak in one of my intercooler pipes that i fixed, and confirmed that the system integrity by watching it hold pressure for close to a minute. The engine has always had the same relatively low level of vacuum while running, even when torn down and refreshed by 2 different specialists over the years. I think it is a function of the drag spec cams and headwork the engine has.

ClintBHP - Thanks for the response! Yes, definitely zero leaks now. I had the entire engine bay sprayed down with soapy water looking for bubbles while the intake system was pressurized to over 25psi I was actually curious as to whether the amount of vacuum the engine has differed to what it had when it underwent its first refresh a few years ago by another specialist racing team, so I had a look at some old videos I have of my gauge readouts after the first refresh that I keep in order to give me some perspective on what the readings look like on Day 1, and it was drawing the same level of vacuum as is now. The previous refresh and this refresh it just underwent were performed by different specialists, yet the vacuum at idle is the same on both occasions years apart. The cams in the engine are a lot more of a drag-spec application than they are for street use, as the engine is fed by a "large frame" turbo. I will make the changes to the map, and report back!

ClintBHP - here is a link to some logs taken after repairing the boost leaks: https://www.dropbox.com/sh/2d0mypzhinq3wvi/AACOzhHgyXecw8THTOPasg1Oa?dl=0

You, sir, are good!!! Really good!! I found a *very* substantial boost leak in one of the coupler connections. It might as well have been a barn door sized leak. The person who dropped the engine back in did not tighten a couple of the clamps on the FMIC leading to the throttle body hard enough, and you could literally hear the air rushing out from the connection as soon as I connected the compressor to the charge piping. In fact, the leak was so great that the compressor was unable to put much pressure into the system initially. I did not need soapy water to find the leak. I could hear the low frequency rush of air clear as day. Clamps have been tightened and boost leak tested up to about 30psi, so I think I should be good for what the car was originally tuned for. I'll take some logs a little later once I have the intake plumbing back together again. Need to get the compressor back to the hardware store ASAP to minimize renting fees

MAP and BAP are reading identically at atmospheric, so I'm guessing it isn't an issue with the map sensor. Nothing much changed in the engine between when it was initially tuned and after the refresh. Went from 99.75mm pistons to 100mm pistons, and a slightly thicker headgasket because some material was skimmed from the block. I just performed a 700km oil change on the engine a few nights ago. I'll definitely look into performing a boost leak test on the engine to see if there is an issue there.

Not sure.. I suppose it is possible that there could a leak somewhere; I'll have to rent an air compressor to pressurize the intake system and perform a boost leak test in order to confirm. I do have some non-AVCS high lift long duration cams though, so not sure if that would cause the low vacuum? I also did not recalibrate the map sensor when I transferred the map over from my V88 to the Link G4+. It wasn't mentioned in the other thread where I was asking about the procedure of making the migration from V88 to G4+. The map sensor settings are identical between both the V88 and the G4+ though when I check the software. Is there a quick way of knowing whether the map sensor is reading correctly?

ClintBHP - here is a link to the logs and map: https://www.dropbox.com/sh/3y3ajrp4tb4zo91/AACxNFy3OBYYi1M75OjnQgwfa?dl=0 With the proper base fuel pressure set, it looks from my layman eyes that the car is behaving better at idle. . I'd love to see what you think. Log 1 was just with the correct base fuel pressure set. Log 2 was with the correct base fuel pressure AND expanding he CLL Lambda limit to 15% as you specified. I experimented with turning on AC on both, but not turning the fans to the max yet. Thanks again

Tested the fuel pressure to see what the base pressure was, and what I found was that base pressure was sitting at 50.5psi with the fuel pump turned on and engine off, when it should always have been set at 43.5psi. I promptly dialled it back to 43.8psi (as close as I could get on the regulator without undershooting 43.5psi). Might this explain why the car was running rich as you mentioned? Hopefully this finding doesn't throw all of the idle tuning you and Adamw helped me with into the bin Driving impressions and logs still to come in a few hours.

Thanks Clint - I'll carry out the change to the map and report back. You have also reminded me of something with your post with respect to running rich all the time....I think I will also check my base fuel pressure to ensure that it is where it should be. For a while, I've suspected that the fuel pressure readings I see on my display might have been very slightly (maybe a few psi) higher than I was used to seeing after getting some diagnosis work done on the fuel system prior to the engine refresh. I didn't probe too deeply since the car seemed to drive just fine from the driver's seat, and AFRs did not look far out of the ordinary. I know the shop adjusted fuel pressure as part of their diagnosis, but I need to ensure that it is back to where it should be. What you are telling me seems to indicate that base fuel pressure might be a little higher than it was when tuned originally. It's quite uncanny how just from a few logs you and Adamw are able to tell so much about what is wrong or right on an engine from far away. Meanwhile, I, who drives the thing around had zero idea anything was off! I'll report back soon.

Clint - took a log at idle with the AC coming in and out, and I think the cooling fans were also coming on and off also. LINKECU FORUM TestMAP - 1.4.pclr log 1 for testmap 1.4.llg I *think* I was able to do as you asked. I'm not sure I can make sufficient changes to the deadtimes in individual cells in order to bring actual AFR in line with target AFR while still keeping the values of adjacent cells close together in value. I did try to trim the figures as you mentioned though. Please let me know if things are on the right track. On other news, it seems that tweaking the deadtimes of the injectors has allowed the oscillating idle to return. Not as bad as before, but it comes and goes. I suspect it might be that the idle lockout isn't high enough... I was going to try playing with it, but only want to make limited changes prior to an expert telling me otherwise

Silly question, but is there a special significance to the value of 0.7 as far as injectors go in general? Or could you have easily told me to use a different deadtime value?

Ahh - My mistake. I will change all the values to 0.7 and try again. Sorry about that.