eric951turbo

So I've replace the oil gasket, new rod bearings, some front main seals etc...

2 problems:

1. No power. The car poorly accelerate. The engine is running smooth, nice sound, no backfires, everything looks ok....
I believe Ive put everything tight in place (not my first time doing this).

The only thing I suspect, is that I didnt put in some new rings / crush at the exhaust/wg, Ive changed them last year when I did the turbo job.

Could a small leak in the turbo exhaust be causing this????

2. I small vacuum leak. I cant find it, at least 2 psi missing. I've tried the carburator spay method and nothing. I'll try Vans way with a compressor at 15psi tomorrow.
Again... could a small leak at the exhaust could affect the vacuum???


AS A NOTE: The carburator spray method doesnt work on my car...
I've unplugged a vacuum a shot some in it when the car was running and made no difference...... shot some on the air filter.... not much difference. Really not enough to stall the engine.

Van

Pressure testing the intake is the best way to find a leak.



Could the cat be plugged? Or the inner wall of the cat pipe collapsed?

eric951turbo

Tks van for you reply.

Ill try the vacuum test tomorrow. As far as the power issue, im running straight pipe.
Could a leak in the exhaust system cause a really low power issue?

Tom M'Guinn

What does the boost gauge read when you floor it -- how high does it go? If an exhaust leak is your problem, then you will see it in the form of reduced boost pressure. Did you double check the cam timing marks? Bypass/blow-off valve getting a good vacuum signal?

eric951turbo

I'm able to reach 15psi of boost... But it takes a lot of time. I would say double the time as before the repairs.

I did double check all the timing marks. But if I was off... Would it cause poor acceleration?

Is there a way to check if the bov is getting a good signal?

Tks for your help

Tom M'Guinn

You can put a vacuum gauge othe bov line at idle and confirm it matches the vacuum at the FPR. Do you hear any exhaust leak?

NM'87 951

apologies for raising an old thread, but on the stock boost gauge, what should it read at WOT? I assume the time it takes to get there is dependent on gear too, but how long should it take to get to full boost at WOT?

Player0

Was there ever any resolutions here? I'm having the same issues after having the timing belt and bearings done. Vacuum looks about the same as always. I still boost to the same amount I set it to last (currently about 20PSI since I had some track fuel left over). Everything sounds better than ever.

But the boost is taking 4x as long to hit. It hits just as hard. I have just as much power as ever. Eventually that is. It's just taking much longer to get it.

I guess I will go ahead and test for pressure leaks as suggested this weekend. But I'm also wondering if timing might actually be a culprit?

Player0

After reading around some, it sounds like if the timing belt is off by one tooth I might have similar symptoms, and might even deliver more HP in the upper RPM range. The car hits hard up there right now yeah. But it feels dead, like there is no torque otherwise.