Car running... barely

[t4-teg]

As some of you know, I bought a 90 GST minus the T.. Someone took the turbo off and replaced it with a NA header and intake.. Anywho, I finally got all the parts to return it back to stock (turbo). I installed everything today, turbo throttle body and elbow, stock 14b, 3'' dp, ported 2g o2 housing, stock IC with piping, stock 1g maf, blah blah..

Now, everything is installed, but the car will not idle. Ive got a huge vacuum leak (autometer gauge reading 5-10in. hg. I drove the car like it was, with the vac line from the j pipe to the WG, 8-9psi. The car rode out pretty good (or maybe im just used to the NA powa ).

It will idle for a second or two with the vac at 15-20, then the vac slowly drops down, then back up then down again to about 5in hg when the car just dies.

Not to mention the turbo is blown, so i cant drive the car anyway, unless I want to kill every mosquito in Texas.

My question is, will a exhaust leak at the head to turbo mani cause the car to run like ass? What about a exhaust leak at the turbo to o2 housing? Im guessing it wont cause the car to run like ass becuase its on the exhaust side.

I really dont know the point of this thread, I already know what i need to do , find the damn vac leaks. I dont have a boost leak tester or the money or time right now to make one, so ima start by deleting EVERY vac line not needed, replacing both the TB gaskets, then go from there.

I guess I do have one question, the leak would have to be pretty big to cause the car to just stall out right? Im guessing its the TB gasket, or like 3 or 4 lines.

IDK... I guess im just frustrated, and want to post something.

 

[black_gst]

you problem is most likely a vac leak and an exhaust leak wont cause an idle problem

 

[black_gst]

and if the leak is that bad you may be able to hear it. just try pinching a few vac lines and listen

 

[GSXSixteenG]

Check the intake manifold gasket and throttle body gasket. Those are usually pretty popular to cause a horrible idle.

 

[t4-teg]

Nah it has to do with the work I did. Before the turbo went in, the vac was dead nuts 20in hg.

Im thinking TB gasket, but who knows.

BTW, TB shaft seals wouldnt cause that bad of a vac leak would they. How can I "test" the seals with a boost leak test. Would the butterfly be loose in the TB or anything?

 

[Tim Melton]

Yes the tb could make it idle poorly if it is leaking. If you want you can make a blt for like seven dollars.Get a 2in pvc end cap drill a hole in it put a valve stem from the parts store in there and you are good to pressureize.Oh you also need a coupler and a bottle of soapy water to spray the tb with.Look for bubbles to find leaks after you pump it up.

 

[t4-teg]

sweet. Ill probably do that Sunday. This might be a dumb question, but I can just use a bicycle pump to pressurize the system correct? I don't have a compressor, and I would think that would over pressurize it, no?