1999 gmc sierra. Truck starts right away in the morning & when I get off of work. When I go to the gym after work & come out an hour & half later, I have to floor the accelerator to get it to start. I already changed the fuel pump & the fuel filter.
U MAY HAVE A DEFECTIVE ENGINE COOLANT TEMP (ECT) SENSOR, U NEED A SCAN TOOL TO TEST THIS PART, THIS IS NOT THE SENDER FOR THE TEMP GUAGE THIS IS THE SENSOR THAT TELLS THE FUEL INJECTION COMPUTER HOW COLD OR HOT THE ENGINE IS, IF IT READS LOW THE SYSTEM WILL GET TO MUCH FUEL AND CAUSE A HARD START, DO U NOTICE ANY BLACK SMOKE WHEN IT FINALLY STARTS?
What size engine? and is it a vortec? engine VIN as well. 8th vin number
have you check fuel pressure? must be above 55psi almost to the T on these engines. 55psi WHILE your cranking. only check when its having the hard start. could have a bad regulator. when it warms up seal may leak. if its not at 55psi and you changed the pump and filter, you have a bad regulator. hopefully you dont have the spider style injector system. they get pricy.
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My '99 Sierra 2500 does the exact same thing. Hard start after 10 minutes being idle, but starts right up after 8 hours or more.
Hooked up a tester, but came up with nothing. Changed fuel filter, ran injector cleaner and high octane fuel. Nothing helps.
When it starts finally, the exhaust smell is rich with fuel, like paint thinner. No black smoke, but a whitish color.
I have the same problem with 5.3 liter chevy 1500 pick-up. When it does start it idles rough, and when you accelerate hard grey smoke out of the exhaust. We have replace fuel tank gauge/pump, fuel filter and given it a tune up.
i have a vortec v6 in my jimmy need to find etc valve can not seem to find it any ne got a diagram to find it
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