When my car is finished warming up it was idling at about 1500 rpm in park. When I dropped it into gear though it would drop to 500 and level out at about 600-700. I figured I would lower the idle in park. I put it at about 900 and when I put it in gear would it stall out often. I kept putting it a little higher until I just decided to put it most of the way back. Now I have it idling at 1400 in park, and every once in a while if i dont give the car enough gas when going into gear (which is sometimes not necessary) it will stall out. One of my buddies said it might be a cracked intake manifold, but he couldnt hear any sound leaks like whistling. Any help would be greatly appreciated. I am a body man, not a mechanic. THanks a lot for your help.

 

This might be a subject for the carb board.
Speaking of, what carb is it?
Any recent work done?
What kind of cam? stock zz4?


That does kinda sound like a vacuum leak, which are hard to "hear" most of the time. Check your vacuum at your 700rpm idle for example, see what that is. If it's low, check hoses, and whatnot, you could also try the official propane leak detection method.

 

I just recently had almost this same problem. I dont know what kind of carb you have, but Ive got an edelbrock 600 w/ elec choke. I got the p/n rpms close to matching the d rpms by setting the lean-best idle mixture. To do this, adjust the Air/Fuel ratio for one side of the carb richer until you reach the highest rpms before dropping back down, If the rpms increase more than 40, re-adjust idle speed. Repeat for the other side. Reset your idle speed once again. Return to the first side, adjust richer to get max rpms once more, then back down 20 rpms. This should be the lean-best idle mixture. I've got other issues contributing to my bad idle and thats in a different forum, but setting this helped alot, from 1200 in park to 800 and staying at 600 in drive.

 

mine has the tuned port injection setup on it. so, any other things i could try?

 

On a TPI the TPS must be reset every time you change the throttle blade position so that the ECM knows that the new setting is now the base idle rpm, idle can't be set with the ECM in control of the idle via the IAC, and in control of the timing.
If a higher/lower idle rpm is desired, the ECM must be reprogrammed accordingly.

The minimum air setting procedure must be used to set the base idle to whatever idle rpm you want, and then the TPS idle volts is set at that thottle opening so that the ECM has a reference point to start from to control to the stock, or reprogrammed idle setting.

Do a search for minimum air, I know there's at least one on this, or the TPI forum.

Here's the post it on. It's the first of the rgarcia63 replies.Minimum Air Procedure

 

is this something anyone with a little experience can figure out and do themselves? or would i have to take it to someone for this? can you either explain the process to me if i can do it, or let me know how much it would cost to get done if you didn't think i could do it. thank you so much for all the information.

 

It would be good to learn this, it's not difficult, or these kind of things will nickel & dime you to death.

If you need help just ask.

 

can anyone help?

 

a shop would probably charge about an hour to do it for you, labor rates are different from 1 shop to another, where im at we charge $65.00 per hour. it really isn't that hard, but most shops have a minimum amount of time they charge for, normally 1 hour, after all, they are in business to make money.

follow the links in the post rgarcia63 put up & i don't think you'll have any problems.