having problems with my 88 supra, wont hold boost

[mk3bandit]

About a month ago i was driving, i went to pass someone and there was a loud pop sound like a tire went out. But it wasn't. i noticed that that it wouldn't go over 2500 rpm or above 2 or3 PSI.

Its a pretty stock supra. Its got a 3 inch exhaust from the turbo back, a boost controller. thats about it for mods.

Im not sure whats wrong with it. im not sure if its my waste gate, TPS, ECU, a fuel problem or what. i know the speedometer hasn't work in a while.

 

[mk3bandit]

as soon as it starts to build boost it hits fuel cut. and kills the motor. i pulled codes - 34 turbocharger pressure signal - vehicle speed signal - air condition switch or neutral start switch signal

 

[hvyman]

boost leak.

 

[mk3bandit]

from the ICP? and we tested the TPS it is out of spec so im going to replace it soon.

 

[SupraDupra500]

Check the intercooler hose coming off the turbo. Those are notorious for cracking from the heat down there by the manifold. I'll bet it split, and if you look around it, it likely has a bunch of tiny cracks in it. Either need to replace that hose (good luck finding a good one) or its time for hard pipes. I reccomend hard pipes.

 

[hvyman]

you can also buy just the lower hard pipe pre bent so it bolts on with 2 couplers.

 

[mk3bandit]

ill have to check that. im going to take them off to look at them better. i was running 14 psi that night, so it sounds about right. because you can hear a big air leak.

 

[mk3bandit]

is there anything else that might cause it to cut off at 2500 rpm or as soon as it starts to build boost? it runs good at idle or in neutral/park it will go to 6500 rpm, and has good vacuum.

 

[BKCressida1718]

this happened to me the other night. its the hose coming off the turbo like a previous poster replied.

 

[mk3bandit]

Im hopping that's all it is. that would be nice. a cheap if that's all it is.

 

[mk3bandit]

So i have ordered CX Racing hard Intercooler pipe kit today, cant wait to see if she gets fixed. Ive missed going to the drag strip and drifting.

 

[Failure14]

If all you have is an exhaust and boost controller && running 14psi
your just asking for trouble guy...

So i have ordered CX Racing hard Intercooler pipe kit today, cant wait to see if she gets fixed. Ive missed going to the drag strip and drifting.

So i take it you didnt even check your IC piping that the others aforementioned....?
Dont start buying parts unless you know its going to fix the problem, i mean an intercooler +hardpipes
is a good investment nonetheless but no need to replace something thats not broken.

 

[SupraDupra500]

Yes, I'm curious as well to see if that was actually the problem. I'm 99% sure it is, just want the satisfaction of knowing I was right j/k. Let us know if that was actually the problem!!

 

[hvyman]

buying new pipes would prolly fix the prob if you tightened them all the way but you could have easily either made a boost leak detector(cheap) or check ALL the ic piping for cracks and loose clamps.

 

[SrBigbutt]

I'm in a very similar situation as the OP. My car was cutting out under full boost so I decided to make a boost leak tester. Found out my lower turbo hose was cracked and most of my intercooler pipes were leaking. Decided to purchase cx racing intercooler piping kit, replace cracked accordian hose, and install an apexi power intake (because stock airbox is a bitch to take in and out!) Did that fix it??? NO!! 8-(

Still got boost leaks!! Did another test and found some vacuum hoses leaking. Pretty much sprayed the whole engine with soapy water. Found out one of my bolts for the lower intake manifold was loose and leaking. So fixed that. Now my ISC gasket is leaking. Its new! But I took it off a couple times. So I will need to order one. I also think something in the EGR area is leaking?? Is that common. I can smell some gas fumes coming from that area when I was doing the test. It would go away when I would unplug the vacuum hose. Any suggestions?

 

[mk3bandit]

If all you have is an exhaust and boost controller && running 14psi
your just asking for trouble guy...



So i take it you didnt even check your IC piping that the others aforementioned....?
Dont start buying parts unless you know its going to fix the problem, i mean an intercooler +hardpipes
is a good investment nonetheless but no need to replace something thats not broken.

 

[mk3bandit]

well the person who had it before did work to it. and for some reason put a PVC pipe intercooler on so i wanted to change it any way, and i cant work on it right now its been snowing alot. but im going to go through it soon and see whats what.

 

[mk3bandit]

this is another reason it think it could be the elbow. a few peace broke off and could have ripped a hole in it.

 

[mk3bandit]

Thanks everyone who helped me out with my boost problem. After tearing my car apart today, I found out that it was in fact the ICP that was my problem. Tomorrow im putting the new ICP on. Im glad that there well knowledgeable people on "SUPRA MANIA". So i hope that putting the new ICP on will fix it for good, I guess ill find out tomorrow.