87 turbo low boost

[Solid Snake]

Ok, I see that tons of people have this problem and there is an equal number of answers and things that could be wrong. But nothing I've found so far has helped. So here is my problem:

I just bought an 87 944 turbo from a guy in Arizona. The car already has Lindsey Racing's 300 rwhp kit installed. This includes:

Dual port wastegate
4" exhaust with Magnaflow muffler
DME and KLR chips
Manual boost controller

The car ran perfect when I got it. It drove the 18 hours back to Texas without a problem. It has the stock boost gauge and it usually hits 2 bar at around 3,300 rpm when I floor it.

Last Sunday I drove an hour to the next town with no problems at all. I then drove 45 min back and stopped to eat, no problems. I then left for home and now the gauge only reads ~1.2 bar and I have little to no boost.

I talked to Lindsey Racing about it and they said check the pressure hoses. They seem fine.
I took it to my mechanic and he said he wasn't sure but it seemed like the boost controller to him because all the hoses were fine.

Today I pulled out the DME and KLR and took the Lindsey chips out and put them back in, hoping something had come unseated. Still no change.

Since it has the dual port wastegate, there is no need for a cyclic valve.

Is there some way I can test the DME or the KLR? I am not very good with testing electronics and this is my first turbo, so treat me like a noob! Any help is appreciated!


Snake

[billy mild]

Even with a wastegate you still need a BOV or recirc valve. If that has failed you will get lower boost. Also I would make sure all your vacuum lines are connected.

It does sound like something electrical since it was like that after starting the car.

[Solid Snake]

I have checked the vacuum lines, they are good. Is there a simple way to check the BOV?

[szabon]

I just asked almost the same questions. You can check the bov by taking it off, flipping it upside down and looking in to see if the diaphram is busted. If you don't see something, you can feel carefully to feel if it is broke.

Apparently the only way to check the comps is to swap with someone. Ask around and see if there is another 951 around you. Most people don't have a problem meeting up, swapping comps to test, and then swapping back.

Good luck!

[Solid Snake]

I have come to a new realization about my problem today. I installed a pre muffler where the cat goes on the car to quite the exhaust and noticed a bad rattle coming from the car. I thought the shop that had installed the premuffler had left something loose so i took it back in. They said that they tightened some bolts and changed out a nut. Upon leaving the shop I noticed I still had the rattle and asked the mechanic to come out and hear it. He heard it and said the pre muffler must be defective.
This afternoon I called Lindsey Racing and asked them about my turbo troubles and the guy told me to take the hose off the top of the waste gate as that would show whether the turbo is working and take the waste gate out of the eqaution all together. I did that and still had the same problem. But when I was hooking the hose back up I noticed the rattle seemed to be coming from where the turbo sits.
So What I think is happening is the turbo is blown and rattling and I am hearing the rattle through the whole exhaust. The rattle definintely sounds like it is coming from where the turbo sits and is louder in the engine compartment than under the car.
So my question is, is it possible for a broken turbo to make this noise? Also, is it possible for the turbo to make that kind of a rattle and still show some pressure on the gauge? And third, if it is blown, is it safe to drive the car till I can get it replaced?

Thanks all!!

[kdjones2000]

It could be that your crossover pipe has loosened from the hot side of the turbo housing and you are leaking exhaust gases, lowering your boost.

I would take off the intake manifold and take a look and see.

Good luck, Keith

[89-944NA]

Pull the j-boot off the turbo, reach in and grasp the shaft, check for play both up and down and side to side, also see if there is play by pushing and pulling the shaft...if the turbo is shot, you will damage it further by driving it. Rebuild cost around $350.

[Solid Snake]

I think you are right on, kdjones2000, there were no bolts at all in the crossover pipe going to the turbo. So after a day of work taking the intake manifold off, the fuel rail, and whatever else needed to be removed, I got bolts into it. But now that I have reassembled it, i have a new problem. The car turns on but runs really rough. It also will not idle, if I take my foot off the gas it will immediately die. I have never taken off a fuel rail or intake manifold. I looked at the guide on clarks-garage.com but I'm sure there is something I did wrong. I am afraid to keep trying different things because I don't want to keep running the engine when its so rough. So I was hoping someone could tell me what might be happening. Again, it is totally possible I put something back together wrong.

Thanks!

[zedsn]

Did you run a new intake gasket and if so are you sure that it is seated correctly and evereything is flat like it should be? Sounds like you could have an intake leak and if I remember correctly it is possible to not get the intake to sit flat when rebolting it up. How were your hoses going to the idle stabalizer valve that is bolted to the middle of the intake? You could also have problems there. Also make sure that your fuel rail is reinstalled correctly. When I did my turbo rebuild job I left the intake laying in the engine bay kinda still hooked up to some stuff and I just moved it to the other side to get it out of the way.

[89-944NA]

Make sure that you installed the Number 1 intake gasket correctly....it does NOT go on the same way as 2-4. Installing it incorrectly partially blocks the injector pocket in the head.

[Solid Snake]

I did not do anything with the intake gaskets. I didn't take them off or put any more grease on them. I am pretty sure nothing fell off either so I shouldn't have lost a gasket. Now I was thinking maybe something is up with the idle stabilizer valve because it has that hole in the bolt and I wasn't sure how to line the bolt up right. I will probably check that today. Also, will it hurt to run the car to test things I try?

[nize]

check the vacuum line from the manifold to the klr and make sure it's not leaking.

[Solid Snake]

Alright, so I finally fixed it. Rather, a shop fixed it. I had messed up one of the fuel injector spray heads, and there was vacuum leaks everywhere. Cost me but she is back running strong as ever! I still have no idea why there were no bolts on the crossover pipe. I can't think of a reason for that to happen. Oh well, there are weird people in the world!