Hard start throughout day fine first time in morning

1996 GMC SUBURBAN
133,000 MILES • 7.4L • V8 • 4WD • AUTOMATIC
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STEW_BNIXA
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  • 1 POST
In the morning the truck starts right up. Every start after that takes twenty seconds of cranking until it finally coughs to a start, and smells very rich. Takes a few seconds to smooth out after start but i am not giving it any fuel, just letting it idle and settle down. Does not matter if the truck sat ten minutes or two hours.

Fuel pressure test:
AM: key on 55.
AM: engine running 58.
ran to operating temperature, shut off
pressure drops 5 lbs in thirty seconds.
pressure dropped total 20 lbs in five minutes.
pressure dropped total 35 lbs in ten minutes.
key back to on pressure shoots up to 55.
Aug 8, 2017 at 6:18 AM
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STRAILER
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  • 53,854 POSTS
Hello,

It sounds like the engine coolant temperature sensor is off and causing problems but what will give us a clue is to read the codes, Here are some guides to get us going in the right direction.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

and

https://www.2carpros.com/articles/coolant-temperature-sensor-cts-replacement'

Please let us know what happens, we are interested to see what it is.

Cheers, Ken
Aug 10, 2017 at 12:09 PM