I have a 88 formula 305/tbi when the car starts and it's still cold it idles at 1800 rpm in park and about 900 rpm in gear after it warms the rpm drop to about 1200-1400 rpm in park and 900 in gear and in gear it's really pulling hard have to use a lot of brakes to hold it back.When its in my gravel drive way it will spin the tires just like I am power braking it.Any ideas of things to start with.Thanks

 

idle issues are usually one of two things in my experience. Either your idle has come unadjusted, or you have a vacuum leak somewhere. I'd lean toward a vacuum leak.

 

IAC or you need to check out your TPS sensor or your computer. could also be a vaccum leak, but i dont think so. this happened to me, my computer had to be reset.

 

Ahh, forgot about the computer. My car is factory carbed so it's not something I think about often.

 

hey thanks ok ozz do you mean the linkage somehow got misadjusted or bent or whatever? The engine was rebuilt before I bought so no telling what happened.

And how do you have the computer reset is that a dealer thing?

I am going to go crazy on it tomorrow after family time is over of course.

 

Well, not so much the linkage, but there should be an idle adjust...some one here who has TPI should be able to know more about it. On a carb it's a simple screw adjust. I looked it up in my Haynes to try and help out but it says that not all models are adjustable. Sorry, I'm the wrong guy to ask about TPI/TBI models.

 

on my tpi, the screw is on the the drivers side on the throttle body plate. but you dont adjust that ever. it is set from the factory, the problem wont be that. check for vaccume leaks. use some rubber tubing and listen for a whistling in the engine. pull off some tubes here and there to check for change in the rpm. its also probably not that. next you have to cleen your IAC. just put the tip of the IAC in some solvent and scrub it. also i dont think its that but i have a used one that is not broken if you want me to sell it to you. i changed it thinking it was the problem but it wasnt. its only missing a gasket. to get the computer reset, i do think you need a special tool to do it. they will repair it by putting factory settings back on your rom. anywho jsut take it to a reputable car repair place or a dealership. it was 56 bucks for mine, so it should be something around there, and they can do it in under an hour. check that first before you start taking everything apart in your engine. you can also check your TPS sensor. i do know how to check that. i got fed up trying to fix it and took it to the shop. i dont think it will be that unless a wire is loose. it is on the passengers side of the throttle body. check that out, could be a wire loose.

 

Actually, on TPI cars, that little screw is used for setting idle. Its called setting minimum air, and if you did it correctly, then you most likely had to adjust this screw since the possibility of it being perfect after 15 years is slim.
I'm sure that the adjustment is similar for TBI motors also.

 

it should be fine. i was told dont touch it unless you have to. its set from the factory like that. i was told by gm guys. a friend of mine works for gm and he asked around the shop for me, and he was told to not touch it unless you know waht your doing, and its about a 2% chance it would be out of enough to make an idle go to 1400 or higher, over night.