Monday, September 06, 2010 - 09:20 am, by: Harley Jones(Dvjzz30)
hey guys im currently trying to diagnose a problem my manual 1j is having....now it only has the problem intermittantly, when it does come it will stick around for weeks, but can also go weeks or months without playing up. It did this on the stock turbos aswell as the t04e and now on the garret too.
when it hits 2psi(and exactly 2 psi), it richens up that much it can barely fire and all i can smell is fuel if i have the windows down and feels like its pulling timing aswell...it does this all the way to about 8psi, and then just clears up like normal and pulls up to about 15psi then richens up alot again.
now ive tried feeding the boost on at many different points through the rev range to make sure its related to boost regardless of engine speed or any other conditions...it will start to pull as normal as it builds boost, then as it hits 2psi its almost like it hits a brick wall, acceleration stops, all u can smell is fuel and at times it even has trouble firing, but then at 8psi exactly it clears up again. i have tried the following to no avail
resetting the ecu (clears it up for 15 minutes to an hour) replaced my plugs and coils with no difference replaced my map sensor with no difference double checked my vac lines and intercooler piping just to make sure theres no little boost leak. if i completely drain the ecu of power for a few days the problem will disappear and then re surface after a few weeks or a month
a good friend said his 1j powered cressida was behaving in a similar fashion at one point and it cleared up after he replaced the caps in his ecu. so i have ordered some caps and ill replace them within the week. does anybody have any other ideas as to where else i could look if its not the caps? hopefully somebody has had the same problem before and can point me in the right direction
Evan Kaio DieHard Beautiful sunny good @ rugby 'Canes' country '91 UZZ31. 92 TT
Monday, September 06, 2010 - 04:14 pm, by: Cihan Aday(Cihan)
Harley, they're exact symptoms of knock sensor signal errors. The wall is ~10 degrees timing retard, the enrichment is max knock correction enrichment. Sometimes one of the sensors aren't functioning, other times its the ECU not functioning as it should.