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I've had some members ask about comments I made on throttle body cleaning. I was chasing a high idle when I found this info. There is a warning in the FSM (at least in 92) about using solvents. This doesn't mean you can't clean a throttle body. Just that you need to use some care in selecting chemicals. At some point in it's life mine was cleaned of the DAG coating which allows air passed the throttle plates at idle.
Here is the info from the TSM (ref: 92 FSM page 6E3-C2-14)
Here is what the Throttle body should look like. Mine had all of the Black DAG removed. Maybe mistaken for carbon build up
Last edited by belairbrian; Jun 2, 2019 at 11:31 AM.
Reason: add reference for pic
I took a peek at my old throttle body and it was all gone on my 1988 if they used it then. I swapped the original throttle body for a new aftermarket throttle body of the same size.
The base of the throttle body on my car was damaged/corroded and I swapped it to a new throttle body. The gap between the throttle plates is so tight on my replacement that it barely lets light through it, I hope this new one will last a while. I just need to find the bottom part with the heater hoses to replace mine.
Thanks again for teaching us about the "DAG-gone" coating... sorry, I couldn't resist.
Best regards,
Chris
P.S. What is the bottom part with the heater hoses called? I have not seen it's proper name and I need to know what it is called before I can buy one
Chris,
GM calls it the IACV/Coolant Cover Assembly (ref: 92 FSM FIG C2-19, page 6E3-C2-13).
On ebay it might be called an IACV plate, IACV housing or some variant.
I was able to find a 94 throttle body NOS. After I changed the plate on the bottom It works great. Also bought another since they are hard to find and it was $75 shipped. SInce I have the Coolant bypass done. I'm thinking about buying the bottom piece that only has the IACV portion, not the water passage.
Throttle Body Cleaning
