elfking

Hey Guys,
My friends NA sounds like its having a Vacuum leak at 4.5k+ and when the whole car is sprayed down with carb cleaner theres no change in idle.

He pulled his upper intake manafold to replace his EGR 6 months ago, didn't replace the plenuum gasket. I think this might be the problem. Anyone have any other places to somehow check other then carb cleaner?

It also only seems to happen when the car is under a load, we revved it up at idle and couldn't hear this leak anywhere. Only while driving around..

Today we also found the CPU was spitting 1 code of pressure sensor, so we replaced the vacuum line to it, and that didn't fix it, so we put my Turbo II (88) sensor in there and the code went away. But he still has this vacuum leak.

We sprayed every vac line we could see and reach, so Im not entirely sure how to test to get it all under pressure so we can find this leak.

If anyone has any ides that would be great. Thanks.

$150FC

take of the uim and check the gasket, check the injector o-rings

elfking

Alright, well is there any way to tell when the gasket is bad other then some obvous of there being rips in the gasket? I know its better to replace it if possible..

But we all know how it is to be tight on money. Which he is so we only really want to be replacing stuff which is definately bad.

Thank you for your help.

J-Rat

iTrader: (2)

Use soap and water, then pressurize the intake with an air source. Look for bubbles.

HAILERS

I doubt you have a vacuum leak that only happens at 4500 rpm. Sorry 'bout that. Just another angle you might try. Maybe it's the relief valve on the acv that you are hearing? Do you still have a acv and does it have the rather large hose on it's bottom that feeds fwd in the cars right fender to a silencer? If that hose is off it's possible your hearing the airpump relieving thru the acv to the silencer.

Maybe pull the BLUE plug off the relief solenoid and rev the engine in the driveway and see if you hear the sound that you have been hearing.

And about that turbo sensor on a non turbo. It ain't geared for that non turbo. Buy a used one for a n/a.

Abou the gasket on the upper intake manifold......unless it has an obvious rip/tear/gouge.....you should be able to keep using it. If you have doubts about it...then just buy a tube of rtv and put a smear of rtv on the mating surface of where the lower meets the upper manifold(on the face of the gasket), then put a smear of vaseline/oil on the upper manifold(metal surface) and mate the two together. The smear of oil/vaseline on the upper mating part will keep the gasket to sticking to it and tearing the gasket when you take it apart sometime in the future.

elfking

Thanks for all the input everyone...

I started doubting a vacuum leak as well which is why I started looking for error codes.. I switched the pressure sensor as a temp fix so I could see if the pressure sensor was leaking from the diaphram... making the weird vac sound( also becuase it was throwing a code.) Will it cause more damage to leave the turbo one in there for a temp basis. He uses the car as a daily driver and I don't so its convient to just let him use it until we can find him another used one. If it will cause more damage somehow then I'll go switch it back right now. I just wanted the code out of the picture while we hunt for this other strange sound.

Im sure this car has everything there, its a mint 87 (80k origional miles) with all the stock equipment execpt for the cold start assist.

We'll take a look for the hose running to the silencer as well as the BLUE plug and see if we can recreate it.

J-rat: I thought of doing that, I don't have access to a air compressor right now, but maybe in the future... just a little bit of pressure and some soap.... I'll remember it. Thanks.

Lastly anyone know the website for cruising performance? I want to send my injectors to be cleaned/flow tested.. Unless someone favors RC engeneering over them.. I can't seem to find the thread that spoke of their website. I know I had it at some point.

Thanks again!

HAILERS

I don't think the turbo sensor will HURT anything at all. The car won't run quite right though. Won't hurt/kill anything for short term use.....weeks/months.

elfking

Ok, just wanted to make sure.


EDIT: I found the website for the guys at Cruzin performance..
Found here:
http://www.cruzinperformance.com/

For others who may be searching... Just spelled differently, which is probbably why searching had a hard time finding it.