When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I just bought a 1989 GMC K1500 with a throttle body injected 350 Chevy. I suspect it is the IAC because it idles at a very low RPM and almost stalls sometimes when you go from drive to park, or from drive to reverse. It's stalled on me twice now when shifting but always starts right back up. It's not causing me not getting to work, but it's more of an inconvenience to have it stall sometimes. I know how to install the new IAC on the throttle body, but my main question is: do I have to recalibrate the newly replaced IAC valve? If so, how would I go about doing this? I'm a bit of a newb to the whole TBI thing since all I've ever driven is something that has a carburetor.
I just bought a 1989 GMC K1500 with a throttle body injected 350 Chevy. I suspect it is the IAC because it idles at a very low RPM and almost stalls sometimes when you go from drive to park, or from drive to reverse. It's stalled on me twice now when shifting but always starts right back up. It's not causing me not getting to work, but it's more of an inconvenience to have it stall sometimes. I know how to install the new IAC on the throttle body, but my main question is: do I have to recalibrate the newly replaced IAC valve? If so, how would I go about doing this? I'm a bit of a newb to the whole TBI thing since all I've ever driven is something that has a carburetor.
Thanks!
Well, thankfully, carburetors are no longer on new cars and pickups. I have overhauled every kind. I kind of like the TBI system of fuel delivery. Its simple and direct to repair, although it wont beat the performance and MPG of direct or multi-port fuel injection of gasoline motors. As to your IAC valve, its as easy as it gets to changing it out, Its right there on the side of the throttle body. You MIGHT be able to clean it, but if not Rock Auto has them for 16 to 39 dollars. Its an easy fix and no, you dont need to calibrate it. I always recommend "Neverseize" when dealing with aluminum item threads, like your throttle body fuel injection unit and the IAS valve.
This is a single injector TBI, but its the same with a twin fuel injection TBI system.
Well, thankfully, carburetors are no longer on new cars and pickups. I have overhauled every kind. I kind of like the TBI system of fuel delivery. Its simple and direct to repair, although it wont beat the performance and MPG of direct or multi-port fuel injection of gasoline motors. As to your IAC valve, its as easy as it gets to changing it out, Its right there on the side of the throttle body. You MIGHT be able to clean it, but if not Rock Auto has them for 16 to 39 dollars. Its an easy fix and no, you dont need to calibrate it. I always recommend "Neverseize" when dealing with aluminum item threads, like your throttle body fuel injection unit and the IAS valve.
This is a single injector TBI, but its the same with a twin fuel injection TBI system.
Thanks! Appreciate the help, makes me feel more comfortable about replacing it.
Another question has arisen:
My check engine light has also been going on and off intermittently. Once when I was driving it home from where I bought it (but it shut off after about 20 miles) and another just this morning, it didn't shut off at all. (But i only drove 14 miles to go to work, so I suspect I didn't drive it long enough to let it run it's course). I don't have an ECM monitor to check for any codes, if it's throwing any. (it just about has to be throwing a code if the "Service Engine Soon" light is coming on, though) Would the ECM throw a code if the IAC valve is going bad, or are there more issues than I think?
Last edited by Tex57; Feb 15, 2018 at 1:18 PM.
Reason: forgot a word at the end of the paragraph
Idle Air Control Valve replacement
