1JZ slow acceleration and wont go past 2500

[RickD]

Hey guys I have a jzz30 1jz swapped 88 supra, i picked this thing up a little while ago. originally i had a problem with the engine flooding caused by the old injector o-rings. since I've fixed that the car will only accelerate slowly and breaks up around 2000-2500. I've replaced the plugs, changed oil, new battery, changed cam sensors, swapped the ecu, tested the crank sensor, tested the coil packs, and currently going through the wiring harness. Any suggestions or pointers much appreciated. Cheers

 

[Turbo Habanero]

Test the MAP sensor and TPS

 

[scottiedawg66]

Codes?

 

[shipkiller]

I would have checked for codes before replacing and testing anything

 

[RickD]

sorry forgot to post that this thing has my head spinning at this point... It has code 12 crank position sensor, cam position sensor, starter circuit, or ecu.

 

[Turbo Habanero]

Well that's definitely your problem

 

[scottiedawg66]

Have you confirmed continuity in the wiring for the sensors you listed? If you replaced the sensors and tried another ecu it might be a wiring issue. Good luck, I know how frustrating chasing these problems is. Hang in there

 

[Shane_402]

I recall having a similar issue when one of the intercooler pipes came off slightly. Do you hear a whistle at all coming from the engine bay? Might be worth checking all the IC pipes anyway.

 

[shipkiller]

since it's 1jz no-vvti, it has a map sensor and a massive boostleak wouldn't stop it from revving freely above 2500

 

[Shane_402]

Yeah well it was just a suggestion. My 1jz is non VVTi and whilst it didn't necessarily stop at 2500, it sure as hell didn't go over it very well.

 

[StiCk3]

popped a hose on mine once and although it was sluggish as hell, it didn't break up at 2500 like the OP mentioned.

 

[OneJArpus]

Bad or faulty crank or cam sensor or wiring will cause your car to run like shit, figure out the code first and it'll most likely fix your issue

 

[mkiiichip]

Check the wires leading to the cam sensors. cut the wire protection back like 6 inches and look inside.

I am totally redoing my harness ATM, and I was surprised at the condition of those wires. They were far worse than the rest of the harness (brittle flaking insulation). Mine could have very easily shorted. Surprised they didn't actually.

 

[ard]

my jzz30 auto 1jz also did not rev past 2500rpms and it was a neutral safety switch wiring gone bad.

 

[JDM CRESS]

did you ever figure out the problem? i might know what it is.