Dealership don't know.. HELP

My Cavy (1998 2.4 Z24 Manual) as been doing this since i brought it a year ago.. and the guy i bought it from said it did it when he got it too. When i start my cavalier it idles funny (goes up and down). And if i do not give it gas and wait for it to warm up it will stall, buck, and sound like shit. I have learned that starting it and leaving right away works (kinda) but you have to give it all the pedal has and pray nothing gets in the way. But sometimes even then it wants to and tries to stall out. It does this when it is cold out or warm out, but other times it doesnt do it at all.... i asked the dealership and they told me two things. I did them and it still does it. And i refuse to take it to a dealership and pay them money to tell me "it could be this". Also, the check engine light does not come on and as never come on when it is acting up. I have replaced the fuel filter, spark plugs & boots, temp coolant sensor. I have run out of ideas and given up, but it is a very embarrassing problem. People think i can't drive stick which is not the case at all. If you have any ideas i would LOVE to hear them!! Also, i have replaced my factory head light with projector head lights.. but my one side always looks like it has water in it... hazey and shit. Anyone know how to fix this ??? Thanks!

fuel pressure regulator
IAC valve needs cleaning

Buy a haynes or chilton's repair manual to help also.

Ditto

the Haynes manual tells you everything about your cav..and possiblle problems..i have one..you can ge it for $16 at an advanced auto parts store, pep boys, or and abc autoparts store..you can also buy them online..

id look up your problem man..but just got done working on my car..and i left it in the glove compartment so i dont lose it..

my 98 z24 (manual trans) does the same damn thing , i cleaned the iac valve & it seemed to help 4 about 1 day. you are right it is pretty embarrassing. i also changed the fuel regulater,injectors,filter,pump,,, map,iac,tps,coolant,intake temp sensors,& computer (ALL NOT 4 THIS REASON) so if anyone has any ideas , i would really like to know also.

I have one of those books on my car from advanced parts. I was told by the dealership to be the regulator, when it is acting up, i should remove the wire going into the regulator and if i see or smell gas then i should replace the regulator. I have checked it numberous times and no smell or gas.

Its going to the garage tomorrow for inspection, i will try to have them clean the Idle Air Contorl Valve and see what happens. Thanks for your help. If you learn of anything else please tell me.

Godenm.... ARE YOU SERIOUS???? If That is the case maybe i should not bother wasting my $$$$... I would really like to know what the heck is doing it though it drives me NUTS.. I hate it! IF ANYONE KNOWS PLEASE HELP!!!!

yes,im serios,i cant figure this thing out!... i forgot to mention i also changed the coils, coil pack cover,spark plugs, & sparkplug boots. its like the cars not getting enough fuel & is falling on its face , but after it warms up its usually ok,,,but sometimes when you shut it off for about 5 min. & restart it will do it again(even when hot)///someone told me it was getting too much fuel,but how the hell is it getting too much? someone also told me that some of these cars had a problem with really high oil pressure at start-up,and said that causes a surge in idle,but who knows?!!?

When you cleaned/replaced the IAC valve did you clean the mounting hole? (Godenm if if helped for one day, you are on the right track.) They get really gummed up inside. This will cause the problem you describe. I have two of these cars and I get to do this about once a year or so. Good Luck.

yes,i cleaned the mounting hole inside of the throttle body,& i ,at least, think i got it all cleaned. i sprayed it w/carb cleaner & took a screwdriver & rag and got into the hole. i was also messing w/ the iac a little while ago & moved(wiggled) the wires going to the iac & it seemed to run differently. u think there might be a short in the wiring or maybe a loose wire pin in the iac itself??

sounds like a vacum leak or a fpr problem

could also be the pump isnt properly able to regulate pressure or a bad map sensor

has something to do with your fuel system though

i thought it maybe a vacuum leak also, checked all hoses, checked & replaced intake manifold gasket., same thing. i just changed the fuel pump also & map. this mite sound stupid, but wats a fpr?

Fuel Pressure Regulator.
You can get a vacuum leak around the IAC if the Oring gets brittle. Also there is a re-learn proceedure if the pintle is moved in or out. A little spin or wiggle is usually okay though.

A short in the wire is always possible, maybe a junkyard unit for testing is in order. They are kinda pricey to but when uncertain.

Do you have a bad smell coming out of the tailpipe? If It smells bad it could be a bad converter.

Clean out the EGR. that might be your problem

brand new cat. converter.sweetcavy,, im not tryin to over your thread, i just would like 2 figure this out also. and i hav tried all these things and no-luck, so no sense in you spending $$$$ like me, tryin to fix it

ialso cleaned out EGR,& changed it w/ another(from another cavi i hav)

I don't want to sound condesending but have you had your injectors cleaned becuase it sounds like a definite fuel starvartion problem. It's not a vaccuum leak because it would constantly rev irratically. A good way to see if it is your fuel line is to use a good injector cleaner with the highest octane fuel you can find for a couple of tankfuls and if this helps it may be worth getting the injectors properly serviced or replaced.