To make a long story short.. I have a 1992 cavalier ...i was leakin a tiny bit of anti-freeze under the head near the thermostat housing..i was told its fairly common... I replaced the head gasket...very very carefully... i had the head turned down and had a vavle job, ive replaced every gasket i can think of that deals with vacuum... and everything is torqued down to gm specs. Here is what is happening.... At idle...my car runs like @!#$...almost like theres a vacuum leak....becuase of the low idle it will miss and occasionally it has died on me. Even though the car idles bad it runs perfect... you get up to speed and you couldnt tell the difference from the day we bought it. Now heres what ive done,
: Ive hooked up a smoke machine... theres no leaks in the vacuum lines anywhere!
: Ive done a compression check on all cyclenders, all were within 5-10lbs of each other and right at gm specs!
: Ive torqued everything down to gm specs!
: Ive made sure over 3 times now that the upper and lower intake gaskets werent seeping air...!
: Ive made sure the timing marks are right on and they are!
: Ive replaced all spark plugs and made sure they are at right depth, ive also replaced the coil packs, plug wires, and even the ignition modual, and still no difference in idle!
: Ive unhooked the exhaust from the manifold and ive canceled out the cat converter and muffler to be in option cuz it still idles rough!
: Ive made sure right size pcv valve was in and it does have a goofy 3 piece o-ring set that ive replaced and still nothing!
: My g/f's car is the exact same kind and ive replaced my egr valve with hers and it made no difference... also there is no leak on that gasket..!
: Ive checked the hose going from the brake booster to intake and its fine!
Im all out of ideas ask away and ill tell you if ive checked it or if i have one on this model.... but i cant figure it out...i need help you guys....
You never said if you checked the IAC motor or did the idle speed adjustment on the car.
Ive replaced the idle air and i read that by following a certain procedure, turning the key on for 15 sec's would set itself and i assumed that its right.... but im waiting for a weekend to go up to school and my teacher and i will try and check for a setting its supposed to be at and then see where mine is ....hopefully theres another way to set that little motor ....but thanks umm looking at it in person me and my teacher are kind of cancleing it out only cuz obviously it was fine b4 and now that i bought a new one and its supposed to set itself were thinkin its not it...but we will try again... im looking for something that i havent tried yet... i am sorry i didnt mention it on the other i did forget to say that...but if you have any other suggestions let me know... i can use all the help i can get
Coolant temp sensor. it's a bitch.
its ur power brake booster, i had the problem with my old car, just change that and ur car will be running fine
^Try disconnecting the brake booster hose first, plug it with your finger or a cork and see if that fixes it. Don't run the engine with it disconnected and open to air.
Erik, I just pm'd you but I see that you already covered the basics.
