99 blazer / cold hard start and stalling

[laughnjay]

99 blazer, 4.3 vortec, 4wd, man. trans. Truck is very hard to start when cold & rough idle then stalls sometimes when cold. If I let the fuel pump run for a few seconds before starting, it would sometimes be easier to start. Once the truck has been running for a while problems all go away. I changed fuel filter & checked fuel pressure. While fuel pump runs with key on, engine off, fuel pressure maxx's out gauge @ 60+psi once fuel pump stops pressure drops to 0 psi. While engine is running pressure is a constant 57 psi.

 

 

Please any help would be greatly appreciated. Thanks

 

Jason

[GM-Tech]

once fuel pump stops pressure drops to 0 psi.

 

It's likely this is your problem. It should not drop to 0. The check valve in the pump is probably bad, allowing the fuel line to drain out, giving the hard start. Need a pump to fix this.

[laughnjay]

once fuel pump stops pressure drops to 0 psi.

 

It's likely this is your problem. It should not drop to 0. The check valve in the pump is probably bad, allowing the fuel line to drain out, giving the hard start. Need a pump to fix this.

 

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Thanks for your help, Thats what I was leaning towards but wanted to make sure before I drop $300 for a new pump.