My 1991 RS will usually idle at about 700 rpm's. In the past few days I have felt some slight surging while waiting for the green light. I have been trying to catch the exact rpm's that it surges too but I haven't been able to catch it in time yet. My estimate would be that the rpm's are surging from 700 up to 1000 or 1100.

What steps do I need to take to correct this problem?

TIA!

 

Additional Info: the car has about 160K miles on it.

 

Anyone ?....

 

You might try cleaning your IAS and TB,just a guess.

 

My old 91 RS 305 TBI did the same thing for a few days before it threw the magic code. TPS. New one takes just a few minutes and all fixed. Test the TPS and see if it is right!

 

my guess is ...............IAC assembly or TB, use brake cleaner and clean TB...., can also be a bad sensor...........

you might need to put it on a computer for about 39 - 55 dollars for diag ....at a garage with scanner.... they will also flush out the iac.... if thats the problem..

good luck i got the same problem with my 85 iroc TPI and i am at this point with the car. if a sensor is reading wrong and the computer is telling the cold start injector to fire...etc....there are alot of derivatives to this problem.

resetting TPS is also possible.

i am taking my car to a garage this week for diag, to many variables for me.

solution for me:

1. so i will start with a computer diag, get my iac counts with there scanner adjust tb if reading is wrong. get feedback on my iac and pintle which i got my eye on ....i am also concerned the problem could be a bad sensor messing up my computer...