Brandonjza80 Posted January 22 Report Share Posted January 22 Hi there, Forgive me if this direct question has already been addressed in a previous thread, I did search but didn't find anything directly related. TL;DR: The car won't start, it will crank and burble and sometimes it almost catches itself and starts but can't quite get there. I have fuel, air, and the coil on plugs have power but they don't seem to generate spark. I have had my Link ECM for roughly 4ish years now with absolutely zero issues until this past October. I drove the car to the gym with no issues, and the car would no longer start when I left the gym. Initially, I was not getting any fuel pressure at the regulator and rail, I replaced the fuel pump and was still not getting any pressure. Played around with the fuel pump control module in the Supra's and somehow I regained fuel pressure. At this point, I was able to start a log file and try to get the car running (see "rough-idle-wont-run.llg" for reference). The car would start, however, it sounded terribly out of time, like it was constantly misfiring and would only stay running if I was playing with the throttle, as soon as I let off the car would die. I'm using R8 coils with a Wiring Specialties harness for the 2jz and Link ECU, both of these are within 10 months old. The following list is things I've tried and checked but seen no changes from: Checked the mechanical timing, and the car is perfectly in time. Tested a new distributor as I am still using the distributor for cam position reference. (no change) Reset spark timing of the distributor while cylinder #1 is at TDC, all timing marks align. Tested continuity to the ECU for all wires for the distributor and coil on plug harness. 12V at the coil on plug main harness power, the highest voltage I've seen from the signal wire which is directly connected to the ECU was 3V. R8 spec is anywhere between 0-5V, however, this reading was intermittent, when testing today I was unable to get any reading from the signal wire. Hooked a timing light up to cyl #1 coil on plug harness, attempting to see if the spark timing was in check, according to the timing light, the spark timing was utterly way off, almost as if it was 180° out, however, this doesn't seem possible based off mechanical timing of the engine. When cranking for extended periods, I'm getting back pressure out of my IACV, behind the throttle body, almost like it's coming from the valves. The car is getting fuel as the plugs are completely soaked in unburnt fuel, it's getting air without question, and spark should be working based on the volt meter tests as well as seeing the coils arc via an external arc test. I know this isn't a forum for diagnosing issues with the car, however, I figured all the info above is relevant to the problem I'm experiencing. I've also attached another file (2nd-gear-pull-w-idle.llg) this was recorded a few months prior to the no-start issue, I guess my main question would be, can someone compare the two files and tell me if anything has changed or gone wrong? I've also attached the tune file directly, not sure if that's helpful or not. I've eliminated every possible option other than something may have happened with the ECU. I can turn the car to ACC mode plug my laptop in and access the ECU, so I know that it is working, but perhaps something within the unit that controls spark has been corrupted? I know I'm forgetting bits and pieces of info so if something doesn't make sense perhaps it will jog my memory so I can clear up any questions. Thanks in advance for anyone thoughts and feedback. 2nd-gear-pull-w-idle.llg Linkg4-neng-Edit-ecu-filel(last-working-tune).pclr rough-idle-wont-run.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 22 Report Share Posted January 22 Your MAP sensor isnt working in the log so it has about 300% more fuel dumping in than it normally would, so start by fixing that to see if it helps. You can test the ignition outputs by pulling the spark plugs out so you can see them, then use the ignition test function to test spark each output. Brandonjza80 1 Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted January 24 Author Report Share Posted January 24 On 1/22/2024 at 2:52 AM, Adamw said: Your MAP sensor isnt working in the log so it has about 300% more fuel dumping in than it normally would, so start by fixing that to see if it helps. You can test the ignition outputs by pulling the spark plugs out so you can see them, then use the ignition test function to test spark each output. I would never have guessed the MAP sensor. Thank you! I'll tackle that sometime this week and report back afterwards! Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted January 28 Author Report Share Posted January 28 On 1/22/2024 at 2:52 AM, Adamw said: Your MAP sensor isnt working in the log so it has about 300% more fuel dumping in than it normally would, so start by fixing that to see if it helps. You can test the ignition outputs by pulling the spark plugs out so you can see them, then use the ignition test function to test spark each output. New MAP sensor is on order, however, in the mean time were you able to see what the boost cut was set to in that log? I was thinking of the MAP sensor control boost cut as well, then that would also determine the no spark signal I was experiencing. Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 28 Report Share Posted January 28 9 hours ago, Brandonjza80 said: then that would also determine the no spark signal I was experiencing. How are you checking for "no spark signal"? Do you have an oscilloscope connected to the ignition outputs? Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted January 28 Author Report Share Posted January 28 11 hours ago, Adamw said: How are you checking for "no spark signal"? Do you have an oscilloscope connected to the ignition outputs? We were checking for any voltage reading through the signal pin on the cops while cranking (this is before you informed me of the test spark function through the Ecu). Quote Link to comment Share on other sites More sharing options...
Adamw Posted January 29 Report Share Posted January 29 If you mean you are checking voltage with a multimeter then you wont see the signal. The dwell time is about 3mS, a typical multimeter wont be able to accurately display anything less than about 500mS. Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted April 11 Author Report Share Posted April 11 Hey there, Sorry to revive an old-ish thread. I have since installed a new Link 2.5 bar MAP sensor, and replaced and regapped spark plugs. Upon calibrating the sensor and testing the car, it still won’t fire up and idle, at most, I get the occasional ear piercing backfire which sounds like it’s detonating in the turbo/exhaust. I’ve retimed this engine 3 times since the start of these issues, so I know timing is not the issue. I’ve tested spark with the test spark function and got a solid strong spark back so it’s not spark related either. I’ve attached the current tune file and log file with the new MAP sensor and plugs, of it trying to start, any feedback to lead me in the right direction would be fantastic. No-start-new-map-new-plugs-24.04.10.llgNew-Link-2.5-bar-map-sensor-tune-no-start.pclr Quote Link to comment Share on other sites More sharing options...
Vaughan Posted April 11 Report Share Posted April 11 Have you checked to see if your timing is 360deg out? maybe try a trigger offset of -120 Quote Link to comment Share on other sites More sharing options...
Adamw Posted April 12 Report Share Posted April 12 Every map I can find from 2JZ NA and TT non-vvt has the trigger offset close to 0, say +/-10 at the most. So it suggests something is way out if your offset of 120 shows the correct spark timing. Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted April 13 Author Report Share Posted April 13 On 4/10/2024 at 6:11 PM, Vaughan said: Have you checked to see if your timing is 360deg out? maybe try a trigger offset of -120 Trigger offset is currently set at 240 degrees with a 2 microsecond delay. I have no idea what I’m doing with tuning so changing the 240 value to -120 isn’t going to do any harm is it? On 4/12/2024 at 4:44 AM, Adamw said: Every map I can find from 2JZ NA and TT non-vvt has the trigger offset close to 0, say +/-10 at the most. So it suggests something is way out if your offset of 120 shows the correct spark timing. Hey, I appreciate the reply. The current offset is 240, ignition lock is set to 10 with a 2 microsecond delay. Could the Antilag/launch control be affecting these values? Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted April 14 Author Report Share Posted April 14 Hey guys, disregard my previous questions, I went ahead and set the offset to -120, no change, so I set the offset to 0 and the car fired up and idled pretty rough but was steady enough that it didn’t stall. CEL was going crazy while it was running, but the ECU returned no faults or codes so not sure what’s up with that. Tried to start the car again 30 min later to try and check mechanical timing but it would not start again. I’ve since compared my original old tune to see if the offset had possible changed itself but it was also set to 240. Quote Link to comment Share on other sites More sharing options...
Tom's r32 gtr Posted April 21 Report Share Posted April 21 Was this issue ever resolved? Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted April 21 Author Report Share Posted April 21 1 hour ago, Tom's r32 gtr said: Was this issue ever resolved? No, it was not. It seems to be timing related but it’s strange that the car started and now won’t start again. Quote Link to comment Share on other sites More sharing options...
Tom's r32 gtr Posted April 21 Report Share Posted April 21 I'm dealing with the same type of issue with my rb26 it'll let out a huge bang from time to time but just cranks and crank and cranks lol Quote Link to comment Share on other sites More sharing options...
Brandonjza80 Posted April 22 Author Report Share Posted April 22 Have you tried anything mentioned above? It seems that my ecu allowed the car to fire if I reset its offset to 0, which to my understanding is basically the base timing, although I can’t replicate this outcome so it may have been a fluke entirely. still no idea what’s causing it to act this way. 15 hours ago, Tom's r32 gtr said: I'm dealing with the same type of issue with my rb26 it'll let out a huge bang from time to time but just cranks and crank and cranks lol Quote Link to comment Share on other sites More sharing options...
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