1jz wont rev past ~2500rpm *SOLVED*

[Hydra]

http://jaycar.com.au/productView.asp...=&SUBCATID=628

$300 though - it seems pretty expensive to be honest, especially when a dedicated unit can be had for half that. Of course the one thats half that price is a single channel one - I don't think I need any more than that?

[MWP]

One of these would probably do the job:
http://cgi.ebay.com.au/UNI-T-UT81B-S...QQcmdZViewItem

Actually, it looks like a decent unit for the price...
http://www.uni-trend.com.hk/UT81B.html
http://www.chipindustry.ru/library/DOC000177991.pdf

Looking at car signals doesnt require a fast/accurate oscilloscope.

[Hydra]

Nice, thats better than the clunky old school CRT ones Much better for working on the car!

[Hydra]

6 new ignitor clips coming, hooray! $10 each

[Jester]

Just a word of warning, your going down the same road i travelled, ECU, Ignitor, Plugs etc.

I have to stress you check the Damper, i know it's a lil bitch of a job to remove but i honestly think you need to.
and swap the TPS.

Don't mean to nag, I'd just hate to see my mistakes replayed.

[Hydra]

Yep no worries, I was going to try it all last night, got to swapping the ECU around and the damn power went out!!! Bloody annoying

I'll check the damper, find a TPS (what else fits?), try another ignitor (gotta find one), anything else?

[Hydra]

Jester, just read through your thread... it's pretty similar I agree. I'll check it out tonight. Yours seems to just splutter and not rev, mine stalls the engine completely.

[MR 1JZ]

how did you go with those ECU's chris?

[Hydra]

The blitz one has had it's caps replaced already, bit of a bitch with that extra board in the way but I got it done. Was that the one that wouldn't rev or the one that wouldn't start?

The other ecu looks pretty fucked... there's no other word to describe it! I'll replace the caps, but there's a nicely fried resistor sitting on the board too (how the hell did that happen!). I'll have my internets back tonight so i'll grab a pic of the one i'm talking about.

Is that non-blitz one the one that was wired up incorrectly resulting in the magical smoke that means electronics have been destroyed?

We might be lucky with it if it's only that resistor that was fried. I'll try find one to replace it.

[MR 1JZ]

The blitz one has had it's caps replaced already, bit of a bitch with that extra board in the way but I got it done. Was that the one that wouldn't rev or the one that wouldn't start?

The other ecu looks pretty fucked... there's no other word to describe it! I'll replace the caps, but there's a nicely fried resistor sitting on the board too (how the hell did that happen!). I'll have my internets back tonight so i'll grab a pic of the one i'm talking about.

Is that non-blitz one the one that was wired up incorrectly resulting in the magical smoke that means electronics have been destroyed?

We might be lucky with it if it's only that resistor that was fried. I'll try find one to replace it.

the blitz one is the one that wouldn't rev past 2500...

the other one is the one that wouldn't start...ahh that thing is a resistor...sorry im a bit of a circuitry nublet...the non blitz one is the factory ECU from my brothers supra...it was never rewired at any stage...thats why im completely dumbfounded as to what has happened

[Hydra]

Oh ok

Yeh your brothers one then looks fairly fried, never know, might be able to recover it. We'll see.

[Hydra]

Ignitor clips have arrived, should have them tonight with any luck. Might be a long shot but hopefully they help!

[Mos]

Seems to be working OK - it was sitting around the 2.4-5V mark on the PIM pin while the engine was off, 1.3-4V while the engine was idling. Revved the engine, it hit the 2.4-5V mark as the engine started it's rev-cut thing.

That doesn't make sense. How much did you open the throttle when you observed it "hit the 2.4-5V mark as the engine started it's rev-cut thing"?

If 2.4-2.5V is the voltage reading at atmospheric pressure - ie engine not running but everything switch on - then you should not ever see that reading unless it's at WOT or the turbos are starting to push some air - neither of which is likely.
If you're only blipping the throttle at idle there's no way for the pressure in the manifold to reach atmospheric - so if your map sensor is telling you it's reading atmospheric, it's gubbed.

Try disconnecting the map pressure line from the manifold - this should simulate atmospheric pressure in the manifold and the fueling should reflect this - if nothing changes when you do this then you know your map sensor isn't measuring pressure correctly.
You could also try disconnecting the map sensor electrically but I don't know what the ECU does at this point so I can't suggest what changes to look for. I'd expect the ECU would still try to run the engine off other sensors, like TPS.

I would strongly suggest finding the threads where the MAP sensor calibrations were being discussed and go from there. You can simulate pressure using a syringe. You can estimate 1 bar of boost by halving the volume of the syringe if you don't have access to another pressure meter. Pending your response as to exactly how you tested the map sensor this is where I'd be concentrating most of my investigation.

BTW, a faulty TPS can exhibit no engine management symptoms at all so I highly doubt that one that measures out correctly will give you anything close to what you're getting. If there are dead spots on the TPS these should be able to be identified by slowly moving the TPS and looking for any nonlinearities in the resistance measurement. (Not trying to contradict you Jester, but I wouldn't be insisting on it as much you are..)

Mos.

[Hydra]

Hi Mos,

Thanks for the suggestions - I wish I had posted this post only a few hours earlier to save you typing it all out!

I managed to work out and fix the problem with the suggestions of Jester! It was that stupid lame 'useless' damper thing. While I could have continued to try and make it work, I got rid of it and replaced it with a generic inline filter. Fired it up, revved smoothly! Woohoo!

The only problem now is the white smoke coming out, and the coolant leakage somewhere at the back of the block. Shouldn't be hard to work out now.

The damper wasn't letting enough fuel to flow into the rail - it would have enough to idle initially, with enough pressure, but as soon as I used the throttle it'd run out of pressure in the rail as the fuel got used, and there was no longer enough pressure for the injectors to correctly spray the fuel.

So moral of the story, don't trust that damper thing at all

White smoke problem will be interesting - depends on the source I guess, not to mention the state of the various sensors.

Thank you everyone for all the help! I'll give rep where I can.

[CrUZida]

Which damper thing you talking about?
The only one on the car is the one at the inlet to the fuel rail.