2JZ- GTE won't start when warm!! HELP!!!

[Hengsta]

Howdy lads,

This has been an on going problem since I got the car on the road and now it's just starting to give me the shits even more.

Need much help as possible.

Ok, well car will start sweet when cold but when it gets warmed up and I go to turn it off for 10mins-1hr and then go start it back up again it SOMETIME starts but most of the time it won't start until I keep trying 3-8 times then it starts ( that's struggling to start aswell).

Anyone have any ideas?? Crank shaft sensor? Cam sensor? Knock sensor?

Another thing it's got is rough idle and when I'm driving say at 60ks and say 2300rpm steady, you can feel the car pops at times??

Would this have anything to do with it running rich? And un tuned?

Car running 550cc and SAFC Neo everything else is stock.

Any help be much appreciated

Thanks,

Heng

[George]

Try to read fault codes - some ox sensor related codes won't bring the warning light but will be instead stored inside ECU.

When warmed up, try to start with throttle fully depressed. That will cut off fuel (any EFI car has similar mode) , making AFR more lean.

the problem does look like WAY too reach. Usual reasons are water temp sensor, ox sensor, fuel pressure regulator, bent fuel line from engine back to fuel tank, MAF. In your case untuned SAFC is most likely the reason.

[midnight_purple_GA70]

check things like battery voltage/alternator charge...

does the car have an imobiliser?

mate recently went through similar drama and it ended up being the imobiliser

but if your alternator isnt charging correctly it could play with the tune and thus make the car run richer or leaner etc...

[Hengsta]

No immobilizer but I do know that my battery is not the greatest!

Alternator is charging fine.

For some reason my fault code is not working? Unless I'm doing it wrong? It's defently wired in.

What I actually have to do to get it started is resetting the ECU that means disconnecting the battery for 2 mins and connect ot again to get it started. Any ideas??

[George]

I would advice that you repair your fault code system first. If the 2jz-gte is a conversion then you might left some wires unconnected.

anyway, check the wiring for ECU pins "TC" and "W". For diagnostics, ground the TC pin and wire 1Wt bulb to W and +Ig.

[BLK_20v]

Bridge them at the ecu... otherwise it could be your ecu that is faulty, seen that on a 4a one where it wouldn't spit out codes

[wilbo666]

I would advice that you repair your fault code system first. If the 2jz-gte is a conversion then you might left some wires unconnected.

anyway, check the wiring for ECU pins "TC" and "W". For diagnostics, ground the TC pin and wire 1Wt bulb to W and +Ig.

FYI, on non-VVTi 2JZ-GTE engines you connect the pin TE1 to E1 (or ground) to enter diagnostic mode (There is no Tc pin at the engine ECU! ).

Codes are then flashed out on the W engine ECU pin

Cheers
Wilbo

[Hengsta]

Will double check wiring!

I did how ever bridge TE1 to E1 but didn't work so must be my wiring!

Wilbo, have any clues what my problem could be?

[allencr]

...it's got is rough idle and when I'm driving say at 60ks and say 2300rpm steady, you can feel the car pops at times??
Would this have anything to do with it running rich? And un tuned?

Everything, plus the usual coil&wire&plug suspects.
Also, have you tried the above suggestion to hold the throttle open, 1/2 or more, on the hot starts????????

[Hengsta]

Tried the full throttle that above suggested and it fucking starts all the time when on full throttle.

Now what does that come down to?

Cheers for all you help!

[George]

as per my suggestion, that means way too rich. Which implies you need to run some kind of diagnostics. I suppose that either fuel trim needed for your setup is out of ECU's capabilities or it's working in open loop.

[Hengsta]

What do you mean by working in open loop?

[George]

Open loop mode does not utilize oxygen sensor(s) feedback, using instead pre-calculated injection duration values. The mode is activated at full load and/or when oxygen sensor fault detected.

If one alters MAF reading, or fuel pressure, or installs higher performance injectors etc... these calculated values will be no longer valid.

Based on ox sensor reading at partial load modes, ECU can compensate for the changes said above, to some degree. Cases are possible when that's not sufficient, besides with ox sensor fault ECU has completely no idea of actual AFR.

[Hengsta]

In that case it can be the oxy sensor that's dud?

[George]

Only as one of reasons. To check for the sensor specifically:
1 Check if there's any of the oxy sensor fault codes present
2 Even if there's none, check for sensor operation

Repair manual suggests the following procedure: when engine warm, increase idle speed to 2500 rpm and inspect sensor's output voltage with fast analog multimeter or (better) with oscilloscope. In every 10 seconds its voltage should switch about 8 times (or more) from 0.2v to 0.8v and back to 0.2v. The faster the transients the better.

There may be other reasons as well.