dryotanz Posted July 4, 2018 Report Share Posted July 4, 2018 Hi Guys Ive got a problem with my car. It is a Toyota Celica Gt4 rally car with the Gen 4 3SGTE, it has had a freshly rebuilt motor and a brand new "milspec" wiring loom with all new sensors and electronics. ECU is a link Fury. we first put it on the dyno and has a misfire at exactly 4800rpm under full boost (19psi wastegate). we narrowed down the problem to cylinder 2. we have swapped around multiple set of coils, spark plugs, injectors and the problem persists on cyl 2. the compression is perfectly uniform across all cylinders.I also removed the valve springs and they were fine. i also ran separate wires for the injector and coil, directly to the ecu bypassing the loom. we also tried another ecu and updated the firmware. I then put a different wastegate spring (10psi) in and the missfire is still there, however not as aggressive. The misfire occasionally goes away but is there 90% of the time I hope you guys may have some ideas on what could be wrong (im now out of my paygrade) Cheers Willy Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 4, 2018 Report Share Posted July 4, 2018 What does it have for coils/ignitors? Also attaching a map and log will be useful. Quote Link to comment Share on other sites More sharing options...
Simon Posted July 4, 2018 Report Share Posted July 4, 2018 Also a trigger scope capture would show a lot, I'm assuming it has the 36-2 crank trigger? Quote Link to comment Share on other sites More sharing options...
dryotanz Posted July 5, 2018 Author Report Share Posted July 5, 2018 it has the factory caldina coil on plugs with built in igniters. at one point i borrowed some brand new high output coils- with the same result. my tuner checked the trigger scope while on the dyno and seemed happy enough (its completely possible he missed something of course) I have attached a log and the tune file Log 2018-07-5 6;08;55 pm.llg rally car.pclr Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 5, 2018 Report Share Posted July 5, 2018 You log shows 3 areas where the RPM limiter has been reduced to 4000RPM due to the diff fuel pressure. Can you try temporarily adjusting that 4000RPM row to the same as the rest of the table and see if that is the problem. Edit: Actually after a closer look, the rev limit thing above doesnt appear to be all of your problem, I see the Lambda go wonky at 4800 with no limiter applied suggesting there is a misfire there. The other thing I would do is reduce dwell time, those coils dont like too much, they overheat with more than about 2.1ms dwell in my experience. Try something like below Still would like to see a triggerscope too please - just at idle will be a start. Quote Link to comment Share on other sites More sharing options...
dryotanz Posted July 8, 2018 Author Report Share Posted July 8, 2018 Hi Adam I did lower the dwell as you suggested as it did seem to make a small improvement here is trigger scope log cheers Trigger Scope Log 2018-07-8 3;32;49 pm.llg Quote Link to comment Share on other sites More sharing options...
Adamw Posted July 8, 2018 Report Share Posted July 8, 2018 Trigger 1 is wired back to front. Swap the crank sensor +/- wires over. Note the ignition timing will change a little when you do this so you will have to set the base timing again. Quote Link to comment Share on other sites More sharing options...
dryotanz Posted July 11, 2018 Author Report Share Posted July 11, 2018 That has sorted it dont fully understand it but it works! I actually had it wired correctly at first, then when it first started, the tuner swapped the polarity as he thought it was wrong. a learning day for all! Thanks very much for your help and quick response. Cheers Willy Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.