Ok i just put a new long block 2.8 in my 83 camaro and i can not find any vacumm leaks and my timing is right why am i idling at 1,000-1,200 rpms?? also when i cut the car off ocasionally it dies slowly if you know what i mean it trys to stay running when ignition is off and finally dies thats just bnecause of high idle right?? and i took the idle screw all the way out to ?? andy thoughts thanks

 

If you took the idle screw all the way out...that should keep the throttle blade closed unless it's stuck open. So the only way that engine could be getting air is through a vacuum leak man. Check around again, and get some throttlebody cleaner or starting fluid. Spray it around the engine a little...if the car stumbles or revs up, then you've found your vacuum leak. Then just pinpoint it.

Is this a carbed car?

 

could be the IAC valve is stock open too far.

Take it out and clean it good, the point should be sharp, if it is rounded off its time for a new one.

Also spray a bunch of carb cleaner down into the IAC valve passage thing to clean it out reall good.

 

if you took the idle screw out, couldn't that have the throttle blade "cracked" a little backwards? also, i thought the IAC was the sensor by the air filter(s). isn't IAC, Intake Air Charge temp sensor...or am i a little confused?

 

Idle Air Control

 

ok, makes sense, thanks.

 

83 is carbed unless converted over at some time.

Their for no IAC
run-on I was told was either due to valves not open/closing right, and timing off.

Did you check/replace timing chain during swap?
Sure valves got adjusted right?
Have you put vac guage on it and verified no leak?
When setting timing, did you un-plug the vac advance, and time it?
Are the throttle blades closing right, or closing to far due to idle screw out?

 

for the vacuum leak, I've also heard that propane works well....and definately better than spraying some fluid all over your engine.

 

yes it is a carbed motor but also its a brand new motor long block so the timing chain and all of the above parts have been replaced. there is no timing advance on my dist unless it is somewhere that i dont know about?? im gonna try the spary to test my vacuum but my carb is part electronic i beleve there is a n iac but its inside the carb and would have to rebuil;d the carb to replace it ( last option) but we will see il let you know how the spray thing works out on the vaccumn leak idea!

 

ok no luck yet this is going to drive me crazy but umung the other things i have an exaust leak and a broken exaust bracket that rattles so its at the neioghbors house getting welded up buit i still cant find a vacumm leak nor can any one else!! ahhhh!!! any more ideas ill keep ya posted on what i find thanks

 

did you put a vacuum guage on it to make sure its pulling a correct vacuum? that'll tell you if you have a leak anywhere.

 

no i didnt try that do you know what it supposed to read keep in mind its different its carbed and a 83 what should the guage read doe4s any one know for certain ??

 

It should have vac advance on the distrib.