Mechanics

CHEVY IDLES FINE BUT STALLS WHEN PUT IN GEAR.

1990 Chevrolet Silverado • V8 2WD Automatic • 100,000 miles

Truck stalls when I put it in gear. I have changed the TPS sensor, injectors, fuel regulator, plugs, wires, cap, rotor, coil, runs/idles strong but then put into gear and it stalls out. Any ideas would be great thanks. 1990 Chevy Silverado 350 V8 5.0L

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Wa
May 23, 2011.




You may have a bad IAC ( idle air control) but try eliminating any vacuum leaks and cleaning the throttle body first. Remove the intake snorkel, have someone hold the throttle wide open for you and scrub the back side of the throttle plate and surrounding bore with an old tooth brush and some carb cleaner. Be sure to spray some into the small holes next to the throttle plate. That should help stabilize the idle. If it still has a problem, replace the IAC.
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Wrenchtech
May 23, 2011.
The IAC was it, I bought it took 5 minutes to put it in fired right up and did not stall when I put it in gear. Thanks for the answers!

Tiny
Wa
May 24, 2011.
You should still clean the throttle body to prevent further problems.

Wrenchtech
May 24, 2011.
Hello. My 1988 does the same thing.I replaced the IAC and that did the trick I thought. An hour later I went out to check it and it was doing the same thing. Starts and runs great untill I put it in gear, then it stalls unless I keep hitting the gas.

Tiny
Silverado88red
Oct 1, 2011.
You need to start a new question of your own please.

Wrenchtech
Oct 2, 2011.
This was a friend of mines truck broken down at my house so I did not know this truck well. It had several things wrong with it and has over 200,000 miles on it. I was working with their low budget so I had limited funds available. It needed lots of repairs (fuel injectors, Throttle position sensor, Fuel Pressure Regulator, IAC, Dist cap/Rotor/plugs/wires, starter, tune up items, etc) all because it was not well maintained. Along with the other things I replaced when I replaced the IAC valve I replaced the Fuel Pressure Regulator at the same time and inside the spring was broken, rusted and corroded. When I replaced them together it helped until operating temp kicked in but in the end I still had the stalling problem. What wound up really finally fixing it was the coolant temp sensor. What I read at the library was when the truck first starts it runs on the main computer using those settings but when it gets to operating temperature it goes off of it. It took me a while of checking everything I had repaired over and over and then I replaced the Coolant Temperature Sensor and it ran good after that. I don't think that part was too expensive either. Like $15-20 bucks. Hope all that helps you!

Tiny
Wa
Oct 2, 2011.
Thankyou!

Tiny
Silverado88red
Oct 2, 2011.

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