idles waaaay to high

[z34power]

hello all. i have a 92 lumina z34, when i start it in the morning the rpms just shoot right up to 3000 rpm, if i were to drive it right away, it will then start to sputter at a low rpm like 300 to 400 and stall, whats up with that????? when it gets warmer it will tend to go down but not right away. it takes some time for that. i do hear a small vacuum leak nothing major but it can be a problem.

can anyone help?????
whaaaaaa!!!!!

[Coyote_Rage]

sounds like a leak. Look at hoses and plastic lines/connecters first.

[93Oldsdroptop]

You gotta fix the vacuum leak. When the engine warms up it expands and closes the leak some, that's why it runs better.

Get some Clean-R-Carb and spray it around where you hear the leak to pinpoint it. When the idle changes as you spray it, you found it!

The plastic lines commonly crack, especially going to the collector ball under the battery.

Good luck!

[96MonteZ34]

ok guys i just picked up a 94 z34 lumina and it also has the same problem. Fortunately i didn't start replacing parts to fix it i found the real problem. These lower intake gaskets leak all the time just like the 3.1's do but there a little more picky. To all you smokers take a cigerette and blow smoke down in the injector valley by the lower intake while it's running at operating temp and watch where it goes. If you watch you can see it get sucked in by the lower intake bolts or you can use some carb cleaner and watch the fuel trim on the scanner change too. My monte carlo had the same problem but it also needed head gaskets as well so i junked that one. Hope this helps i know how much of a headache these engines can be.

[85_305]

It could also be a TPS that's shot. Ask me how I know.

[z34phoenix]

well just recently had an issue with my MAF sensor... iknow the 92's dont have these but maybe there is a sensor that is bad causing it? had exact same symtoms... only i have a scaner and i could see my maf wasnt throwing any info. so i knew the problem right a way.

i think the obd1s use air volume or something else other then a maf sensor.

[toms92gp]

It does sound like the intake gasket, or maybe a malfunctioning idle air control valve. Vaccum leak will do it also.

[Juglenaut]

My bet is on the lower intake gasket, any takers???