HELP!! 1jzgte feels different suddenly

[wynne240]

I need some help figuring out a problem. I have a 1jz swapped 240sx and the car has been running really strong and great. I went to go for a drive the other day and now the car feels weak. I have a singled 70 trim turbo and stock map and everything else and a apexi neo for future tuning. The turbo (when I hit the throttle) sounds like a cold air intake from a n/a car very loud. The boost still reads fine but it felt weak so I turned it up and it hit 20lbs on a stock map ans no fuel cut just weak power. Can anyone help or point me in a direction?????? There are no boost leaks btw. Thanks for any info

 

[Clint]

Sounds like your turbo took a shit. Check your turbo for play...

Sent from my ADR6400L using Tapatalk

 

[te72]

You sure there aren't any leaks? I popped an intercooler hose off on the way to work once, and it was quite similar to how you describe... loud as hell, but quite slow.

 

[wynne240]

Yea im sure all the piping is intact the noise is commimg from the intake on the compressor when I hit the tgrottl. The turbo stops spinning at idle sometimes but when I hit the gas it spins freely. Would a blown turbo still be able to hit 20psi and not smoke?

 

[wynne240]

Also it didn't hit fuel cut on a stock map with no bcc or Fcd could that happen with a blown turbo too?

 

[525gte]

Also it didn't hit fuel cut on a stock map with no bcc or Fcd could that happen with a blown turbo too?

does it idle or cruise normal still?? is it just a under boost problem? take the cold side of the turbo off ck for play in the shaft. may be sloppy and binding

 

[bioskyline]

yeah im with it being shaft play. the turbo shouldnt stop at idle, it should always be spining.

 

[wynne240]

It idles normal just when I go into boost it feels like it has no balls. It has a little shaft play but spins freely. The thing that gets me is not hitting fuel cut but reading like 18 lbs of boost.

 

[te72]

If a turbo EVER stops when the engine is running, you have a problem.

That said, on the high boost pressure without hitting fuel cut, that would depend on a couple factors, the MAP sensor you have being key to my knowledge. Fuel cut on a 1j is based on the map sensor, correct? If you put a different map sensor on (2j, GM, etc...), you could have changed your fuel cut point.

 

[525gte]

It idles normal just when I go into boost it feels like it has no balls. It has a little shaft play but spins freely. The thing that gets me is not hitting fuel cut but reading like 18 lbs of boost.

what kind of boost controller are u using? a bad seal at the header to turbo may be passing enough thru it to stop the spin at a idle.. but it would have to be big hole. maybe crack ing header.. but it would lean out badly under boost.. have u tested the boost controller or gauge to make sure ur making the boost ur claiming?

 

[87M-GTE]

the turbo shouldnt stop at idle, it should always be spining.

If a turbo EVER stops when the engine is running, you have a problem.

Sounds like neither of you have experience with big jb turbos..

 

[IBoughtASupra]

I have a 76 journal bearing, never stopped spinning.

 

[ifyouaint1sturlast]

Sometimes when my 2JZ idles low around 600 rpm (runs quietly and smoothly) my turbo will stop. But it picks up immediately when you hit the throttle (7,8,900 rpms..) T70 JB ..

 

[T701jz]

Sometimes when my 2JZ idles low around 600 rpm (runs quietly and smoothly) my turbo will stop. But it picks up immediately when you hit the throttle (7,8,900 rpms..) T70 JB ..

+1
Your waste gate might not be fully close or might be opening too soon.

 

[te72]

Sounds like neither of you have experience with big jb turbos..

You would be correct in assuming that here. Do they occasionally stop spinning at idle? That doesn't seem healthy to stop/start like that... so the exhaust is just blowing by the turbine without having any meaningful impact?

 

[IBoughtASupra]

The exhaust is just blowing by the turbine without having any meaningful impact?

I find this happening to be very hard to believe. Seen 80MM idle at 900 RPM and never stopped on a 2JZ.

 

[JPsToyota]

If a turbo EVER stops when the engine is running, you have a problem.

That said, on the high boost pressure without hitting fuel cut, that would depend on a couple factors, the MAP sensor you have being key to my knowledge. Fuel cut on a 1j is based on the map sensor, correct? If you put a different map sensor on (2j, GM, etc...), you could have changed your fuel cut point.

The only way he could have changed his fuel cut point with a MAP sensor was if he put a sensor in there with a totally different scale, as the ECU reads a voltage (4.2 ish, I don't remember the exact V) from the MAP sensor. So the map sensor could output to infinity but if the scale is the same, it will always cut at 14-15ish psi (which equals 4.2ish V to the ECU).

If he messed up the scale with wrong MAP, the car would either have been running like shit or blown up by now.

Speaking of blown up, do you have a wideband on the car? You are scaring me with the "stock map", it isn't working turn it up to 20psi stuff. Makes me think something really bad is going on here. Check for vacuum leaks, ton of vacuum hoses on the 1J manifold, though these would cause high idle. Make sure your MAP sensor is still plugged in and still has a vacuum hose on it. I've blown off just about every hose at least once at 20ish psi.



You guys are giving him turbo and exhaust side advice when apparently the car is spooling up 20psi no problem, maybe it isn't the turbo?

 

[Supra-Man18]

Any engine lights? Had the same issue and it turned out my knock sensors were pulling timing : /

 

[te72]

Thanks for the correction JP, I haven't done any tuning on mine, was just a thought. But didn't you know, when it isn't running right, the answer is always MORE boost?