dunl

My new to me 87 951 is laggy....and it comes and goes. No real get up and go, and the turbo usually reads anywhere from nothing to just under 1 bar (need to go and research if that is normal or not).

So I did a compression test just a few minutes ago. Now, I'm not an expert, and everything I do is Internet-taught, so I may not have had the tester properly seat in the plug openings. However, I did make sure that they were seated evenly in each one.

Test results? Pretty much right on about 120 for each cylinder....118, 120, 120,119.

Now, I'm guessing that I didn't seat it properly. If these results show low compression, I'd be amazed if each cylinder was this much in line with all the other ones.

Thoughts and suggestions?

I_am_imprezed

did you do it at wide-open-throttle?

IGROWL

Did you read this?

http://www.dietersmotorsports.com/Co...akdowntest.htm

dunl

No, I did not do it at WOT...missed that part somehow. I only did the compression test, not the leakdown test. And yes, I did read that article. The car was at operating temperature.

JimV8

Those readings are really close and look pretty good.

dunl

Thanks. I'm guessing the air filter is really restricting the engine. I have one ordered (should be here Thursday), and plugs are coming in on Monday. If that doesn't open it up, then I need to start looking elsewhere for issues as to why it doesn't have a lot of get up and go (and when it does, why it gets up and goes away).

xsboost90

yeah a turbo is a lower compression motor- i would check into a faulty waste gate- these are known to stick open and bypass alot of boost. I believe you can vac. check the diaphram at the top of the wg.

dunl

Thx, I finally came to that conclusion late last night as well. Lots still to learn about these cars.

86 951 Driver

Okay your boost gauge should read about 1.75 Bar of boost. When the boost gauge is at 1 bar that means its really 0 LBS or 0 bar. Then whatever is past that is your boost. But these boost gauges are notorious for being faulty. So I would check all your vacuum lines/ replace them and maybe look into your faulty wastegate.

I'm having low boost as well only .4/.5 bar. Should be about .7 bar.

dunl

Going by Clarks garage, I was going to pinch off the vacuum actuating line to the wastegate...where the heck is it?