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stalling...

jamespetkau

By jamespetkau
in Ask A GM Technician

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jamespetkau New Member

jamespetkau

Posted
Posted

i have a 1990 gmc sierra 1500 with the 5.7L, the problem being when i am in gear (forward or reverse) the engine wants to stall at low rpm, however there is no such problem when in neutral or park. before i start replacing parts, i am wondering if anybody knows what this could be or how to know at least what it isn't. the engine is internally stock as well as the transmission. thanks.

bmcduffy Enthusiast

bmcduffy

Posted
Posted

Hi James,

I don't know if this is the same thing but it sounds like what my wifes 92 Sunbird went through a few years ago.

 

I am assuming you are running an automatic tranny. When she slowed down it felt like she was in high gear with a manual tranny and you forgot to put in the clutch, and it would stall out.

 

Now, I don't have the paperwork in front of me and I can't remember the name of the part but it was some sort of module in the auto. tranny. Wasn't too expensive and it definately fixed the problem. Dealer said it was a common problem. Hope this helps.

 

Boyd

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted
I don't know if this is the same thing but it sounds like what my wifes 92 Sunbird went through a few years ago.

 

That's the infamous TCC solenoid problem that affects many 125 transmissions, like you had in that car. His truck does not have that trans and does not suffer from that problem.

GM-Tech Senior Enthusiast

GM-Tech

Posted
Posted
i have a 1990 gmc sierra 1500 with the 5.7L, the problem being when i am in gear (forward or reverse) the engine wants to stall at low rpm

 

Lots of distributor problems causing that in those years. Sometimes, oil would wick up the distributor shaft and soak the inside of the distributor. In most cases, it would just be the pickup coil magnet material deteriorated. At low speeds, not enough of a signal could be generated to trigger the module to fire the coil and the vehicle would stall. Get the RPM's up a bit and this wouldn't happen.

 

I'd look to the pickup coil.

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