1998 GMC Sierra poor starting, smell of gas no fuel leaks

Tiny
MULE460
  • MEMBER
  • 1998 GMC SIERRA
  • V8
  • 4WD
  • AUTOMATIC
  • 91,000 MILES
The engine is a 7.4 liter/ 3500 series. I have R & R the upper Manifold repaired the vaccuum hose to fuel pressure regulator, removed the injectors and sent them out for cleaning. The injectors were supposed to be spraying properly and electrical was good. Service eng light works with ignition on eng off.

I had a pool of fuel at base/of manifold when I broke it down I cleaned the throt./Body and upper manifold, removed all standing fuel.
The only time I had a service code was in 2001 when a O-2 sensor went bad. I have 22# of fuel pressure when key on/ engine off, and 56# when running, I did not do a bleed down test.
Will a cam sensor or a crank sensor cause this without tripping a code?
Fuel Pump?
What do you think I should do now?
I still feel this is injectors not closing. I will appreciate any help you could give.

Thank You in advance, Bill
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Friday, February 5th, 2010 AT 3:29 AM

3 Replies

Tiny
2CARPRO JACK
  • EXPERT
Did you check the fuel ressure regulator when you did the vacuum hose? Those regs blow out, and fill the vacuum line with gas, which causes the vacuum line to fail. All injector o'rings new? When you do injector o'rings I use a very thin film of motor oil to lube them so they dont get nicked, if the top o'rings get nicked they can leak fuel. Check the reg first
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Saturday, February 6th, 2010 AT 8:23 AM
Tiny
MULE460
  • MEMBER
Yes, I checked that when the manifold was off and I had to replace the rubber hose to the regulator after washing the engine and the liquid that came out was only water. With manual vacuum check had no leak of fuel in rubber hose.
Thanks, Bill
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Saturday, February 6th, 2010 AT 10:06 PM
Tiny
2CARPRO JACK
  • EXPERT
If it had a puddle of fuel, it must be an injector leaking or a bad upper o'ring on one of them
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Saturday, February 6th, 2010 AT 10:33 PM

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