1991 GMC Sierra starts, then stalls when hot - The 1947 - Present Chevrolet & GMC Truck Message Board Network

57chevyman · 07-23-2014, 09:54 PM

hey ya'll,

my brother has a 1991 GMC Sierra... it has the 5.7 engine.

it starts and runs great when cold. idles nice and smooth.

when the engine is hot and has sat for about an hour after shutting off, it will start and stall and be very hard to start. the problem only happens on hot summer days. if the truck sits long enough to cool off, it starts and runs normally.

bufmatmuslepants · 07-24-2014, 06:14 AM

If start by unplugging the timing advance wire, it should be on the passenger side by the firewall, and see if that allows it to start again. Then I'd check the coolant temp sensor as when they fail your PCM thinks its cold as hell and dumps fuel trying to warm it up.

07-23-2014, 09:54 PM	#1
57chevyman Registered User Join Date: Oct 2013 Location: Massapequa Park, NY Posts: 873	1991 GMC Sierra starts, then stalls when hot hey ya'll, my brother has a 1991 GMC Sierra... it has the 5.7 engine. it starts and runs great when cold. idles nice and smooth. when the engine is hot and has sat for about an hour after shutting off, it will start and stall and be very hard to start. the problem only happens on hot summer days. if the truck sits long enough to cool off, it starts and runs normally. __________________ Frank 1957 Chevy 3100 2000 Silverado z71 SOLD 2012 Ram 1500 Quad Cab 1992 International 4700

07-24-2014, 06:14 AM	#2
bufmatmuslepants Junior Member Join Date: May 2007 Location: Hampstead, NC Posts: 313	Re: 1991 GMC Sierra starts, then stalls when hot If start by unplugging the timing advance wire, it should be on the passenger side by the firewall, and see if that allows it to start again. Then I'd check the coolant temp sensor as when they fail your PCM thinks its cold as hell and dumps fuel trying to warm it up. __________________ 1979 K10 reg cab short bed 33x12.50s - GONE 1988 4x4 reg cab long bed 337k miles - GONE 1995 Z71 GU6 G80 F44 ext cab short bed 149k 305/70/16s - GONE 1995 NZZ GT4 2dr Tahoe 3" lift 14 bolt sf 155k 305/70/16s - GONE 1994 Z28 M6 1995 Z71 GT4 G80 ext cab short bed 215k GONE 1997 GT4 G80 Yukon 4 door leather, sunroof 168k miles GONE 2003 Avalanche Z71 GT4 G80 165k miles



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