91 GMC hesitates when cold. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Slatherd · 11-21-2005, 10:27 AM

My 91 GMC has just started doing this recently since its started getting colder up here. When I start it up, it starts fine and idles fine. If I leave before it gets warm it sputters and staggers till the temp gets up there a little.

This is a bone stock 91 TBI 350. Fuel filter it about a year old. I am running a 170 deg thermostat, as I do have a chip. Other than that all is factory.

Any ideas?

**Boog** · 11-21-2005, 08:08 PM

Considering the age of the truck it could very well be the coolant temp sensor mounted in the intake manifold next to the thermostat housing. They're not expensive and can make one run terrible.

piecesparts · 11-22-2005, 05:40 PM

I imagine that this truck is also a TBI setup, I would look at replacing the "Cold Start Solenoid" to make sure that it is cycling properly. If the truck is stying on the solenoid to long it will run rich and bog on acceleration.

11-21-2005, 10:27 AM	#1
Slatherd Registered User Join Date: Jan 2005 Location: The great white north Posts: 46	91 GMC hesitates when cold. My 91 GMC has just started doing this recently since its started getting colder up here. When I start it up, it starts fine and idles fine. If I leave before it gets warm it sputters and staggers till the temp gets up there a little. This is a bone stock 91 TBI 350. Fuel filter it about a year old. I am running a 170 deg thermostat, as I do have a chip. Other than that all is factory. Any ideas? __________________ Check out my profile to see my truck. 1991 GMC 2500.

11-21-2005, 08:08 PM	#2
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 14,116	Re: 91 GMC hesitates when cold. Considering the age of the truck it could very well be the coolant temp sensor mounted in the intake manifold next to the thermostat housing. They're not expensive and can make one run terrible. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver 'primer is finer' Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-22-2005, 05:40 PM	#3
piecesparts Parts and more parts Join Date: Nov 2003 Location: Lebo, Kansas (middle of nowhere Posts: 6,821	Re: 91 GMC hesitates when cold. I imagine that this truck is also a TBI setup, I would look at replacing the "Cold Start Solenoid" to make sure that it is cycling properly. If the truck is stying on the solenoid to long it will run rich and bog on acceleration.



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