Does anyone know the size and pitch of the two screws that hold the TPS to the throttle body? I bought a used 52MM TB from a guy who broke the heads of the screws off when he was installing his new 58mm TB. I had to drill them out and now I need to install the correct size Helicoil inserts.

 

They are a very uncommon size and thread for some reason. Probably another of GM's attempts to frustrate us.

I've tried at several auto parts stores, AutoZone, O'Reilly's, Pep Boys, NAPA, and none had replacement screws or even knew the thread and pitch. I took one to Ace Hardware and couldn't match it up with anything there, either metric or standard.

I suppose replacement bolts could be ordered from Eckler's or Mid America or even GM. They may even know the thread and pitch, but finding the correct heli-coil would be another problem.

If I were you I'd just skip those bolts and go with something like 1/4 inch fine thread. They're really not that critical and only serve to keep the TPS from rotating.

If my TB threads were stripped that's what I'd do.

Hope this helps.

Jake

------------------
1986 Corvette Coupe, 415 CID, Edelbrock 6073s, ZZ9