Well I have a pretty nagging problem. Basically my car won't hold boost for ****. I have tried everything that I know of, INCLUDING unhooking the wastegate line and leaving the wastegate shut, even then the car only goes to 13 psi, just like it does with my boost controller on it.

The culprit the first time was a cracked manifold, which I have gotten fixed 3 times already but can't find any spots of concern right now. The charge pipes have been checked a billion times, there are only like 4 connections everything else is welded, and they are all silicone with T-bolts. The car held 18psi for about a week, and then it gradually dropped to 17-15- and now it only goes to 12-13, even with the wastegate closed.

OK Now I am trying to figure out what to check next.

I am going to
- Replace Turbo compressor gasket.
-Replace wastegate
-Replace all pre turbo gaskets, even though they are all fairly new and everything is tight.
- I am thinking about replacing the head- I had problems with it before, it actually did the same thing, but the car didn't want to rev at all. Now the car revs decent, but there is no boost. So I am un decided on this.

Oh and for info on the setup. GO here.

https://honda-tech.com/zerothread?id=1264338

A few addtions since then, HKS Bov, and some other misc. things.

I am just looking for suggestions.

 

intake manifold gasket?

 

It is new, but that is on the list as well. Kinda hard to explain, but pressure is definitley escaping from somewhere.

 

Update: I wired the wastegate closed, and still get 13 psi and no higher. So I guess on to charge pipes. I checked the turbo, it is fine, nothing is wrong there.

 

Have you checked the I/C itself? A friend of mine popped a weld on an endtank once, that caused a simialr problem.

Also: Boost is just a measure of air sititng in the manifold when the valves are closed. unless you think your valves aren't sealing at all, then theres really no way the head can be the problem. I would tend to think bad valves would give you some more indicators that there is a problem than just leaking boost.

Have you visually inspected both the turbine and impeller wheels? If something passed through the exhaust or compressor side, it may have damaged the fins and caused a boosting problem.

Just some ideas, hope it helps.

Zak

 

yea, I did visually inspect the wheels, they are in good shape.

I had a recent problem with the head. It wasn't valves, but the LMA. They weren't in correctly. I took the overhead assmbley off and re did it and it was perfect. Now it is happenening again, but it will still rev well, before it wouldn't rev for ****.

Found a little hole on the compressor outlet flange. I am going to fix that and see what happenes. But it is pretty small, I don't think it is the problem.


Modified by 93turbo16 at 4:16 PM 9/10/2005

 

Well another update.

I have concluded. The turbo is fine, wastegate is fine, charge pipes are fine. Just as I thought.

Now what is left. I guess Intake manifold gasket. I replaced the TB gasket, that is peachy. It is between the IM gasket and the head being junk.

 

What BOV? Maybe it's leaking, is it an adjustable? Tighten it up a little if so, just for testing. Did you check your intercooler, like mentioned above?

 

HKS race gate or whatever blow off valve, and I have messed with the adjustment, with it, even swapped out BOVs. I didn't test the intercooler, but I may do that next weekend. We took the over head assembly off today and that wasn't the problem either.

 

have you tried doing a pressure/leakdown test on the charge pipes from where they connect to the throttle body to where they connect to the turbo? , you say its not the couplings but it could be one of the welds leaking or as mentioned before the intercooler, testing from end to end would eliminate all aspects of the charge pipes/ intercooler.