In the mornings, when I first start my car for work, which is a 92 rs with a 305 tbi, she first idles at about 1500 rpm and slowly goes back down to the normal idle of about 700 rpm in park. It takes about 4 to 5 minutes for this to happen. Also, if the car is already warmed up and I try to start it after shutting her off, she will idle at around 1,000 rpm and not go down until I put it in drive. Why is this? I assume this is normal, but correct me if I am wrong.

 

I played around with prom editing software and noticed that the stock chip does have a "choke" programed in.. It's set to idle @ 1500 but can't remember the temp margine.. it won't do it when its hot or even half warm.. well shouldn't anyway.

 

it should initialy run the revs up a bit whenever you start it, to build oil pressure. the high idle you figured out. as for it running high on hot start, i dunno, i haven't looked at an automatic bin, and my car doesn't do that , it will start, rev up to build oil pressure, then drop down to the 600 rpm range.

 

high idle on cold start is normal. It wouldnt start or stay running in cold weather if the IAC didnt open up and remain open. As the engine aproaches operating temp, the IAC counts will fall off to what they should be when its warm. On warm start itll idle high mnomentarily but it should fall off after a few seconds. Does the idle come down if you just let it idle in neutral?

 

You guys are talking about idle flare, and it has everything to do with the IAC park position. It's normal.

 

It will come down if I let it idle in neutral if i start it cold, but if I start it hot the lowest it will get in park is about 900 rpm, but once you put it in drive it goes right down to normal idle.

 

thats a bit high. It should be closer to 600 or so. When in drive itll always come down because of the loading from the torque converter. Have you made any adjustments to the tbi and are there any vacuum leaks?

 

I have done nothing to the car at all. There might be a vaccum leak, but i dont see why it would only do it while warm.

 

900rpm in park is normal for a tbi stock chip. So is 600 in gear. (auto)