2JZ VVTi Shutting Off

[robbieb2009]

I'm having an issue with my 2jz vvti swap. It will shut off under boost in the higher rpm ranges at what seems like different rpm's and not all the time either. Sometimes I'll get on it and it'll shut off in 2nd. Sometimes 2nd will run fine then shut off in third. Car has a cd009 with a new wiring specialties harness. Motor is completely stock with the twins in true twin mode.

What do I mean by shut off? The car completely dies and I coast to a stop. Then with the key still in the "on" position I try to start it by switching to crank and it does not fire at all. just cranks and cranks and cranks. Then when I turn the key to "off" and all the way back to crank it starts right up like nothing ever happened.

I'm not getting any major codes (only 89 due to traction control) even when I simulate the problem and keep the key on and ecu in test mode (in case the code is a non stored one). This is what has me mind blown. I ground out the TC pin to get the CEL to flash at me.

I'm borrowing a friends ecu and igniter this week in hopes of that fixing the issue. Anyone on here have any similar problem or heard of it?

Thanks,

Robbie

[robbieb2009]

Update

Tried both the ecu and igniter with no luck. But I did find out something else. I can rev the car all the way to redline while driving if I keep the load low and build almost no boost at all. When I get into it hard, building boost, it seems like a "hard" ignition cut occurs.

When this happens its still the same problem as earlier where it won't start back up until the key is off then back on.

I'm thinking myself now that it is either a major sensor like crank or cam angle sensor or knock sensors. Will try a different MAF as well.

Thoughts anyone?

[robbieb2009]

Continuity checked the cam, crank, and knock sensors last night. Cam ohm'd out fine and crank sensor ohm'd out just a hair high. 2.3 Kilo-ohms compared to max in manual of ~2.0 Kilo-ohms.

Knock Sensor one was open and knock sensor two gave a reading of 25 Mega-ohms and kept climbing up to 40 Mega-ohms then went open. Manual wants 1 M.

I have two knock sensors arriving tomorrow and will try those. Still confused on how a knock sensor could do this. Although a fail safe for a bad knock sensor reading is to retard the ignition timing to max. I'm guessing that can cause my issue as the fix in the manual is key "off" which is what I'm seeing.

Oh the fun of swaps.

[robbieb2009]

UPDATE - Rod Knock

Replaced knock sensors and same thing kept happened. Then the car started acting even more weird and well what would you know, now I have horrible rod knock and she is pretty tight. Takes three batteries to get it to crank over and start.

I take it my knock sensors were trying to tell me something was wrong and kept putting it into fail safe mode to try to alleviate it (still lost on no codes at all; though the manual says codes are thrown for the knock sensors only when something is wrong with the sensor or circuit itself; not necessarily if its working and picking up knock????). I couldn't hear anything until it was easily heard so don't say I should have known.

Will be pulling the block and taking it to my machine shop to see if I can just bearing it or not. Will be picking up a 2jz-ge short block as well just in case.

[heartofmadnes]

Hey did you ever figure out this issue, I have the exact same problem in my mk3 supra swap...Car runs great until you try to get into boost...Ignition totally cuts shutting car off...I have to turn ignition all the way off then back on to start the car back up...

[robbieb2009]

I never figured it out 100% but I'm relating mine to a bad motor. No 3 and No 4 rods had bad bearings and no 4 eventually was wiped out so that is when I heard the rod knock.

I'm saying this because in the manual a fail-safe for engine knock (picked up by the knock sensors) is to keep cutting ignition timing until its fixed and to reset this you have to turn ignition off. A knock sensor can pick up any abnormality in the engine; doesn't have to be detonation.

I believe my car was picking up knock, cutting ignition timing all the way until it was too much cut out and shut off. Thus the ignition off fixed it because that is in the ecu to reset ignition timing back to normal once ignition was off. Follow me?

Can always fine the 1998 Toyota Supra manual and look at page DI - 162. That's the diagnostics page for the 2jz-gte that has all the fail-safes on it.

At this point I'm 90% sure that was my issue. Really hope its something different for you but sounds real similar.

A indicator I never picked up on when I did this was, remove the oil line to your vvti solenoid, inside there is a little metal screen, if you have metal in there then you are probably in the same boat as me. Also I hope you are running 93 fuel right? Incase yours just is detonation.

[heartofmadnes]

I rebuilt the entire engine, so I'm hoping its the speed sensor since I do not have it connected as of yet, trying to see which wire to run it to since it uses a different signal. Im thinking its retarding the timing to zero since it has no idea what the car is doing speed wise but is seeing boost. Yeah I did a fresh top in with new rings and bottom in with bearings and all new seals around head deck..valve seals the works, broke the engine in on a stand then drove it for about 2 months now..again it drives great but if you try to get it into boost under WOT something it killing the ignition. Hate to go to a standalone right away...Everyone is saying that the stock ecu on jdm vvti are the biggest headache..So far they are right

[robbieb2009]

You do your harness yourself or have it made? If made maybe contact who did it to ask about the speed input.

Also wouldn't hurt to just check your knock sensors just in case as thats about the only fail-safe I find in the manual that is fixed by ignition off.

Wish you luck though! Keep at it and you'll eventually get it.

[heartofmadnes]

Originally Posted by robbieb2009

You do your harness yourself or have it made? If made maybe contact who did it to ask about the speed input.

Also wouldn't hurt to just check your knock sensors just in case as thats about the only fail-safe I find in the manual that is fixed by ignition off.

Wish you luck though! Keep at it and you'll eventually get it.

Yes did the harness myself And just went over many of the wires all seemed fine..Will see..I just may have to go stand alone

[robbieb2009]

Well it’s still doing it. I am now completely lost...

[Syrussilvia]

Have you tried another MAF?

[heartofmadnes]

Just to add to this thread I am also having this ongoing issue. But have some added information. After the car gets to full warm up, it no longer shuts off under boost. But only after getting to full warm up, so I changed out the ecu thermostat sensor since that controls fuel/air mixture during cold and normal operating temp...But no change when still warming up, will shut down then not start back up until ignition is switch fully off then back on. For now I enjoy the car very much, but only after I let it warm up in the driveway first..lol...Or just keep it out of high boost until my temp gauge states its good to go. But dying to figure this one out, and yes I have tried another MAF..no change..uugg

[Kingtal0n]

What does the wideband say

This all boils down to tuning and possibly mismatched parts. I bet you have the wrong injectors for the maf or the wrong maf for the ECU. I've seen this happen a LOT with RB engines, someone would buy an engine and piece together the electronics... and it would run fine, driving around. But go into boost and it would run lean, blow the pistons apart or damage bearings because of pre-ignition. The engine features a complete 'fuel cut' to try and stop the damage, but if you kept trying over and over...

Instead of blowing up more engines, just use a wideband first to ensure a/f ratio is in the right range. Tune the engine around the right a/f at least.
Then figure out if the timing is right or not. Factory computer runs too much timing for 93 octane American fuels typically will use 16-18* when only 12-13* is wanted. So the way I recommend setting up a factory ECU 2jz-gte swap with reasonable power and NO stand-alone is to use methanol to make the addl timing somewhat safe.

[heartofmadnes]

I bought this motor almost 10 years ago with maf and everything included..and I tried another maf since I have like 3 of them..lol...I'm thinking of going with a stand alone and getting away from the aristo ecu..But the wide band is reading..between 11.3 and 12 on start up about 14 to 15 warm..wot does 11..or so if I recall..again it runs great when warm..But a better tune may help..I'm also big single with turbonetics T77 so...just going to keep playing around until I get it right..

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[Kingtal0n]

Im confused. If you have a huge turbo you need big injectors. Which means the ECU has been retuned.

If you have a huge turbo and a stock computer with stock injectors well there you go. thats the problem.
You'll toast engines all day like that.

[heartofmadnes]

It's running a piggy back...I'm going with a standalone...I've had this car for 20+ years and the engine is sound. Since robbie was having the same issue with a stock set up is the reason I join the convo...seeing are local Turner next week so it's all good..

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