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Hey people, I am having some issues with my truck. Keeping it short and simple. I drove it a few weeks back, parked it, the next morning it would stumble/die when the accelerator was pressed. CEL codes for CPS, IAC and MAF showed up. All have been replaced, along with the Cap/Rotor. The truck idles fine, but stumbles when the accelerator is pressed. I did a home made smoke test, and am unable to find any vacuum leaks.
Suggestions?
Last edited by CJG_GTX; July 5th, 2020 at 8:53 AM.
Hey people, I am having some issues with my truck. Keeping it short and simple. I drove it a few weeks back, parked it, the next morning it would stumble/die when the accelerator was pressed. CEL codes for CPS, IAC and MAF showed up. All have been replaced, along with the Cap/Rotor. The truck idles fine, but stumbles when the accelerator is pressed. I did a home made smoke test, and am unable to find any vacuum leaks.
Suggestions?
Sounds like a fuel injection issue. Check your fuel pressure PSI.
I agree with @oilcanhenry . I have the same truck I guess as both of you and recently my truck would take a long time to start, it would crank a long time. In my case it turned out to be a bad check valve in the fuel pump, so it was taking time to build up pressure. If memory suits me the fuel pressure point is under the hood, towards the fire wall slightly to the drivers side. I believe it is a black cap and faces upward, should be a shcrader valve in their. Conveniently placed so you can set the gauge on the windshield I might add.
Sounds like a fuel injection issue. Check your fuel pressure PSI.
Originally Posted by oilcanhenry
60 PSI is ideal, but GM say 55 to 62 PSI. I have the same year Chevy pickup as you, so this should be interesting.
Okay, So I ran the fuel pressure, and can post a vid if I figure out how. It starts around 55, then drops to 50 psi. When I touch the gas, the pressure jumps to 60, then I let off the peddle it drops back to 50-54. Sometimes as low as upper 40's.
Okay, So I ran the fuel pressure, and can post a vid if I figure out how. It starts around 55, then drops to 50 psi. When I touch the gas, the pressure jumps to 60, then I let off the peddle it drops back to 50-54. Sometimes as low as upper 40's.
Was the drop to 50 PSI at key on, engine off, or just at start up? At key on, engine off, pressure should hold and not lose more than 2-3 PSI in 5 minutes.
Was the drop to 50 PSI at key on, engine off, or just at start up? At key on, engine off, pressure should hold and not lose more than 2-3 PSI in 5 minutes.
At every touch of the pedal, it jumps to 60, then back to 50-52. Once hitting as low as 48.
Was the drop to 50 PSI at key on, engine off, or just at start up? At key on, engine off, pressure should hold and not lose more than 2-3 PSI in 5 minutes.
key on engine off, it sits around 55. Overnight it dropped to 44.
July 5th, 2020, 8:49 AM
'98 K1500 4x4, Stumbles/Dies.
