I took off the throttle body on my 1985 Fiero to examine because the car starts hard and runs poorly at idle. Eventually it will die and I have to restart. I tore down the TB and found a fair amount of corrosion everywhere including the throttle bore. I was suspecting the air control valve wasn't working properly and when I removed it the seating area in the TB was very corroded and likely was providing a poor seal. I am thinking of dressing the seat somehow. My idea is to turn a lapping mandrel from soft steel or brass and attempt to lap the seating area with valve grinding compound. Has anyone done this before or is there a better method to clean up the seat IAC seat?
Randy
theogre
NOV 28, 12:24 AM
I don't think some "rot" in/on the TBI is your problem. Having low fuel pressure &or iffy ignition can cause crap idle to engine stalls.
As to "rust" problem in IAC port... Maybe better to find another TBI but can try this...
Use a "dremel" w/ variable speed & sand paper disk. Run on lower speed so paper won't shred or eat the body. Many "dremel" have 1 or more grades & a lot of them because Very Cheap to bump the parts count in most kits but very few ever use them.
If too tight to fit in there, "dremel" flex shaft may work better.
Put armature in middle of hole to let sand paper touch the whole seat. Can try small felt wheels w/ polish compound after worse crap is off.
many "dremel" copies/clones take same flex shaft etc on the threads on the body but not all. If have 18-20v battery system some have a "dremel" kit that work w/ same. Example: Ryobi has several flex shaft tools as stand alone units or to work w/ "dremel" tools. If you get a Flex shaft, do not bend the shaft tight. Place/hang the motor so this won't happen.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
