Vrank

iTrader: (4)

1992 factory 5 speed car
Jzx90 1jzgte and r154
No wideband til next weekend
car breaks up bad past 2000rpms and builds boost in neutral if you try to rev through the break up

Okay so I swapped my gf's car with a jzx90 1jzgte. Bought the engine from a kid going ls1 in his tourer v mark2. Car had 89k on the clock, and a known bad ecu. I decided to build a harness from kinda scratch utilizing an aristo ecu I had laying around while waiting on shipping from Canada.

Setup 1: 96 obd2 auto sc300 harness, gutted and repinned to work in a 92 5spd. I added in all ignition and timing and everything else to make it work on an aristo ecu and to work like stock using jza80, my tsrm for my car, and other random diagrams.

Car fires first try. Idles gorgeous. A/C is working, reverse lights, speedo, tach, EVERYTHING. It catches temp, pull out, start to go and starts hitting a brick wall around 2500ish. Bring her back in.

Put in new plugs

Pull coils off of my daily holset powered 1j car that I push 15-18 psi through daily, no change

Boost the coils I removed to 18psi on said daily just fine.

Swap igniter and map from daily, no change

Compare ohm readings of every sensor you can think of with those of my daily, spares, and a buddy's

Built inline fuel pressure tester, key on has 42ish, Fired it drops a bit like mid 30ish at idle

Installed walbro in place of stock pump

So since I've only converted harnesses previously (1jz both vvti and non, 2jzge into 7m car) I figured it had to be wiring like maybe picking up noise since this was my first full harness build. Also didn't have another aristo ecu to test, so decided to just convert the x90 harness into the stock sc harness since I have a running 1j daily with confirmed good spare parts.

Setup 2:

92sc stock harness, plus jzx90 harness, ecu from my daily
Get this together, put into car, does the same thing. Absolutely exact same thing. Everything works great until you get above 2000 rpms. A/C works and everything just like the other harness/ecu combo.

I have unpinned pin STA, no change. Also, I know these really aren't needed as my daily utilizes neither.

I hooked up my Emanage ultimate to compare logs to my daily mainly curious about timing. Seems to be the same as my daily around 18* at idle.

Anyone have any other ideas? Between this and the long hours at work and never ending maintenance on the other cars my brain is fried. I have a feeling it's something stupid simple. Just can't see it.

Vrank

iTrader: (4)

Also wanted to mention I added an extra 0 ga ground from battery to engine. I've moved the grounds around with no change, and my car will fire with the igniter flipped onto the plastic side although everyone says it grounds through the casing, although it is bolted into place on the shock tower. Car still idles gorgeous, and doesn't overheat even with the a/c blowing snow.

stockhatch

iTrader: (12)

Wow, extensive troubleshooting there. Kudos to you for effort

Have you checked the TPS for correct calibration and correct resistance scaling across a full sweep from closed to WOT?

Can you view all sensor inputs from the EMU? If so I would look closely at MAP, TPS, and knock.

Just to eliminate them all for sure, you could swap cam and crank sensors from your daily.

Trevstuh

Is the aristo

Trevstuh

Is the aristo ecu bad?

Vrank

iTrader: (4)

Thanks. I try to be thorough before asking questions. I think tomorrow I'll scribe the tps on my daily and swap it, but the full sweep voltage wise seems to be fine. You have to set voltage for tps at closed and wot, and the scale is about the same. Nothing erratic as I slowly depress the throttle. This is the reason I haven't actually swapped it.

As for knock, I'll try reconfiguring the emu to monitor. It will throw codes for them if you unplug them and run real crappy.

Map sensor voltage is normal. Haven't seen anything close to fuel cut voltage, even clamped voltage at same place as the daily that's never even seen it and nothing.

I'm hoping the wideband shows me something. When approaching/encroaching on the break-up which is coincidentally around vaccum in neutral, it starts fluctuating kind of crazy. I assume it's because it's starting to miss. Anyone have any experience with stock fpr failing and doing this?

Also, plugs are bkr6egp. But I've had these model plugs on literally 3 different 1jz's with stock twins that ran perfect gapped out of the box. The plugs in it were mis-matched Bosch/ngk/hks and it did this then. Idle cleaned up considerably with the platinum 6's.

Vrank

iTrader: (4)

Trev, where you at in tx? Pretty sure the aristo ecu is fine as it does the same problem with it and a mark2 ecu, and two different harnesses.

Things I'm hung up on:
Grounds. I'll keep adding more. I had problems with grounding on the ge before this and it would run for seconds crappy then cut out. Think it was at the drivers kick panel junction block. Maybe I'll strip the car and weld every damn ground point in the tsrm to its place haha

Fuel pressure regulator
Haven't had any problems from one of these before so not sure what to look for.

Thanks for input

stockhatch

iTrader: (12)

I would not suspect grounds would be an issue across two totally different harnesses. Always good to ohm them out and make sure they are solid, but I doubt that's an issue.

Regarding FPR, you should be able to pull the vacuum line and look for fuel. If you feel brave you can suck on the line going to the FPR and see if it holds vacuum or if you get a mouth full of fuel. Obviously, a mouth full of fuel means a ruptured diaphram

Vrank

iTrader: (4)

Well, I'm thinking more along the lines of body grounds affecting the +b circuit or others that could disrupt something important. When it had the ge something around the junction box was loose that caused havoc. The car was hit in the door and they replaced it, and did a crappy job before I got it.

I will try your suggestions for the fpr. Thanks

Vrank

iTrader: (4)

Forgot to mention, car does this without seeing boost. Took off the charge piping and does it at the same spot.

Also cleaned out the cam sensors where they plug in

99SC42

iTrader: (44)

Try to get a CEL

Justin727

So you're running a Auto ECU on a 5speed correct?

Vrank

iTrader: (4)

Quick sc4: no codes. I've forced both ecus to display multiple codes to make sure they weren't the problem.

Justin727: yeah, auto ecu. Doesn't matter though. That's irrelevant. They work just fine. My daily is 1jz with an r154 that's been running stateside for two years and some change on the same ecu that I'm using for diagnostics.

Didn't get a chance to check the regulator today, but will get at it tomorrow. I spent this afternoon scavenging capacitors from fryes/other ecus to fix my friends sc400 that left him stranded last night. Also, I think I'll do a resistance check of the injectors, and check voltage across the battery when it starts cutting out. Hoping that I'll get my o2 bung comes in so I can start monitoring fuel. It doesn't smell rich. Plugs didn't look rich either. Looked about normal for what little use they've had

99SC42

iTrader: (44)

IGF wire at 58b on the ecu will do that too..comes from ECU to Ignitor.

Vrank

iTrader: (4)

I can't see igf being a problem here. The fact that the problem is exactly the same between a 1jz harness/ecu and a 2jz harness/ecu and multiple igniters is making me think it's a hardware problem.