Freshly rebuilt 1JZ won't stay running.

[Sam]

I have a 1JZ in a JZA70 Supra that has been rebuilt. It originally died from two pistons leaning out at wide open throttle. When it died it had:
-440cc injectors
-SAFC II
-Blitz Access ECU
-R34 Skyline fuel pump

Cause of death at the time was thought to be myself playing around with the SAFC II, but the cause has changed since then. I'll delve into that later.

Now the mechanic had rebuilt the engine (which took a long freaking time, almost a year) and started it up. It ran like extremely rough for about 10 seconds, then died. He determined the fuel pump wasn't staying on. So I bought a Walbro 255 and replaced it. Same story after the replacement. The fuel pump would not stay on. So he opened the Blitz Access ECU and saw a burnt terminal. On the opposing side of the board it looked like a capacitor may have burst. So he thought that when the ECU died, it told the fuel pump to shut off. Which happened to be at a time when I was flooring it. Karma?

So taking no chances, I found a stock manual transmission JZA70 ECU (I sold my stock ECU when I first purchased the Blitz unit. Bad idea.). It took forever to get here (2 months) and we popped it in. Same story. It runs smoothly for the 5 seconds it lives for, unlike the Blitz ECU, but still dies. My mechanic performed the 12v mod to the fuel pump to prevent it switching between 8v and 12v. Also he hard wired it so it would stay on when the ignition was on, so there was no chance of it turning off. Also he closed the FPR so the injectors would be well fed as a test.

Still, the car refuses to stay running. And only for about 2-5 seconds each time. This is extremely frustrating as my car has been in the shop for 14 months now. Everything with the build took forever or went wrong.

Also it should be noted that the O2 sensor is not hooked up as I have a single turbo kit. There was no stock bung for it to go into, so the mechanic is waiting for the car to run before he sends it to the muffler shop to have the exhaust refitted and the 02 sensor put in place. He claims the car does not need the O2 sensor to run while it warms up, so he is not concerned about it being fed into the exhaust. He plugged it in to see if it would run with it attached, but it still did not make a difference. Note that when he did it, it was merely laying on the engine, not being fed exhaust fumes.

Would having the O2 sensor plugged into the exhaust make a difference? Could it be bad MAP sensors? He noticed the 1JZ has two. I only thought there was one in 1JZ engines. Could it be that the stock ECU (which was purchased here on Supramania) is also is malfunctioning? Or are both ECU's fine?!

I'll take photos and make a video later on and post them.

Any comments and thought are greatly appreciated!

 

[f00g00]

My car did something similar in that it would start, run for a few seconds and then shut off. The cause was when I closed my hood, the aftermarket hood strut disconnected, extended all the way and jammed into the fuel pump relay on the inner passenger side fender and disconnected the small 2 wire plug, so it cut power to the relay.
If yours is hardwired then it might be bypassed.

 

[te72]

I'll take a stab at it like I always do... same old suggestion too. Works for me and pretty much everyone that's had the same problem I did, but some people think it's a bad idea without giving a better one. Anyway, I digress. Try giving it about 1/4 throttle after you start it. What's it do when you do that?

If it stays running you could either have a bad/stuck ISCV or a need to adjust your tps.

 

[JonoTurbo]

Are you throwing any codes?

Also, there is only one map sensor, but there is a pressure sensor for the boost gauge which looks like a map sensor.

 

[WeDgE]

Do you have a fuel pressure gauge on the FPR?

You said the previous engine died due to leaning out on 2 cylinders, but are unsure of the cause. Have you checked/replaced your fuel filter??

 

[Sam]

My car did something similar in that it would start, run for a few seconds and then shut off. The cause was when I closed my hood, the aftermarket hood strut disconnected, extended all the way and jammed into the fuel pump relay on the inner passenger side fender and disconnected the small 2 wire plug, so it cut power to the relay.
If yours is hardwired then it might be bypassed.

I'll ask my mechanic about that. He did hardwire it, so I'm not sure it'll be the issue. Thanks for the response though!

I'll take a stab at it like I always do... same old suggestion too. Works for me and pretty much everyone that's had the same problem I did, but some people think it's a bad idea without giving a better one. Anyway, I digress. Try giving it about 1/4 throttle after you start it. What's it do when you do that?

If it stays running you could either have a bad/stuck ISCV or a need to adjust your tps.

I believe my mechanic tried adding a bit of throttle after it was started, but it didn't help. I'll double check though!

Are you throwing any codes?

Also, there is only one map sensor, but there is a pressure sensor for the boost gauge which looks like a map sensor.

I don't believe its throwing out any codes. Its very bizarre, it has everyone very puzzled. Do you know which one is the main map sensor??

Do you have a fuel pressure gauge on the FPR?

You said the previous engine died due to leaning out on 2 cylinders, but are unsure of the cause. Have you checked/replaced your fuel filter??

It's the stock FPR, so there is no gauge. But at one point the mechanic had put a gauge into the fuel rail to see what the pressure was at. I don't recall what it was. I vaguely recall him saying it was normal a couple months back.
Yeah, fuel pump and the fuel filter were replaced. The old filter was VERY dirty apparently and needed to be changed out.


I'll try and get a video and some pics up soon!

 

[JonoTurbo]

The engine map sensor is the one with part number 89420-24040. It is mounted on a small black bracket generally. The sensor for the boost gauge won't read vacuum, so if you have that plugged in as the engine map sensor, that may explain why the car wont run.

Also, if you haven't opened up the stock ECU to check it out, I would suggest doing so. The caps could be blown in that one as well and causing this problem.

 

[Sam]

This is the engine starting up and then mysteriously dying after a couple seconds.
http://www.youtube.com/watch?v=ftqx0tD7nzY

This is a second later, trying to start it again. It wouldn't start.
http://www.youtube.com/watch?v=gQ8LndMBFo0

Pics coming soon! I have to go to work

 

[Sam]

Here's some pictures of my car thus far for anyone who's curious.

A problem could be that the MAP sensor and the boost sensor could be mismatched? Dale thinks not.

The engine as it sits today

The new used ECU I bought. I hope its working properly.

Cool Beetle

 

[JonoTurbo]

Yeah I was just taking a guess on the map sensor thing, but yeah you definitely have them in the right places.

EDIT: Just for the hell of it, try unplugging the o2 sensor. It seems like it could cause trouble the way you have it hooked up there.

 

[Sam]

EDIT: Just for the hell of it, try unplugging the o2 sensor. It seems like it could cause trouble the way you have it hooked up there.

Originally, it was left unplugged all together. But Dale (the mechanic) decided to plug it in to see if it would help. It didn't make a difference.

On Monday I'll go down to the shop and see what's happening. On Sunday he's borrowing some guy's crazy scope thing. I don't recall what he called it, but it had scope in the name. It can read 4 difference feeds of information (like injectors, various sensors, etc.) and record what's happening with the engine. He hopes it will properly diagnose what he hell is going on in my cursed 1JZ.

 

[te72]

Gremlins. That's what's going on in your cursed engine. Takes a lot of trouble to get rid of them all in a Mk3. On an unrelated note, NT05's, nice tires... I just picked up a set and love them.

Just noticed your car is RHD too... damn Canucks.

Anyway, I may have missed it, but how's your timing? I remember timing giving Clint (zerocool on here) a hell of a time when we first got his car running. It would start and run for a bit, but never stay on. Come to find out, either one or both of the cam gears were 180* off... completely opposite.

 

[Sam]

Gremlins. That's what's going on in your cursed engine. Takes a lot of trouble to get rid of them all in a Mk3. On an unrelated note, NT05's, nice tires... I just picked up a set and love them.

Just noticed your car is RHD too... damn Canucks.

Anyway, I may have missed it, but how's your timing? I remember timing giving Clint (zerocool on here) a hell of a time when we first got his car running. It would start and run for a bit, but never stay on. Come to find out, either one or both of the cam gears were 180* off... completely opposite.

Thanks! I was waiting for someone to notice the NT05's haha. I actually haven't gotten a chance to test them out yet, but I've heard nothing but good things about the NT05s. The rims and tires are brand new and have never seen the road. Just a dusty shop floor.

Yuppers, it's the real deal, a JZA70 R. I got it imported back in early '07. It was a huge pain in the ass to get here.

Really? I'm no mechanic so I couldn't even tell if the cams were 180 degrees off. When the engine was being built I had brought Dale a set of HKS timing gears to replace the stock gears. I wonder if those somehow it threw him off? Is it a common mistake to set the cams like that? How wonderful would it be if that was the only issue!

 

[te72]

You'll like the tires. I have 275's mounted all around on Mk4 TT (rear wheels on all 4 corners) and they stick about as well as could be expected of a 3800lb car. Great straight line traction (bit of spinning around 6000 rpm or so on a hard launch) but I've been taking the freeway exit by my house that would squeal at 60 before with the old 555's (same size, just old) and the NT05's give me a feeling that they could probably take more speed around the corner... Scary. I don't have the balls to explore this tire's limits on the street, I suppose that's a good sign, right?

On the subject of the cam gears, they spin twice for every rotation of the crank, remember? So when all your marks are lined up properly, if your #1 cylinder is at the bottom of it's stroke instead of the top like it's supposed to be, your timing is going to be 180* off.

It's easy enough of a mistake to make, and doesn't take *too* long to correct if it is the problem... I'd look into it.

 

[Sam]

I've got 275/40/17 in the rear and 255/40/17 in the front. I should have gone with a 245/40/17 in the front in retrospect, it would have made the rears look wider by contrast. Oh well.

I talked to Dale about the cams being 180 degrees off. He's certain they are correctly positioned. His logic is that the engine wouldn't be able to run or run as smoothly as it does (even if it is only for a couple of seconds) if they were off by 180 degree. He is still trying to find a fault in the fuel system. I'll go down there when I get some extra time and see if he's made any progress or found out anything new.

 

[kikdurazz]

this is pretty basic but tell me after 14mths of sitting you guys put fresh fuel in the tank. :icon_wink

 

[Sam]

Haha, yes, he did put fresh fuel in the tank.

Small update: It lives!! But only by the use of the shop's mobile fuel pump device. Dale plugged it directly into the fuel rail and adjusted the device to pump 40PSI of fuel, and it actually ran! I almost threw up when he told me. He said when he tested the fuel pump (he didn't gauge it to see what PSI its putting out) he said it was pumping fuel in a very healthy manor. The fuel lines is another story though. He overlooked them completely.... So when he gets more time, he's going to go over them for obstructions or debris (and likely replace them all with new lines). Hopefully this fixes the problem.