Mechanics

CHEVROLET TRUCK ENGINE PROBLEM

1995 Chevrolet Truck • 162,000 miles

1995 chevy k1500 5.7l tbi. First thing in the morning start truck it runs for a few seconds then dies. Start it again and it runs a couple seconds then dies. This continues for a few minutes then the truck will stay running the rest of the day. Next morning starts all over again. Ive replaced oil pressure sending unit, pickup coil, ignition module, plugs and wires. A few weeks ago I replaced fuel filter, extremely dirty and the truck started up fine any time of day for a few days. Then it went back to the start die start die. Also checked fuel pressure. Undone fuel filter and with key on engine off was reading 10 psi.
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Klay
February 28, 2013.



Fuelpressure is ok, check for a vacuum leak undr the tbi unit, they tend to blow gaskets there. Uses choke cleaner and spray around it if it idles well or pick up rpm then you found it.

Hmac300
Mar 1, 2013.
I just checked the fuel pressure again this morning and with the key on 10 psi. Start the truck with the gauge still hooked up, pressure goes to 11 for a couple seconds then the pressure drops off to nothing and a second later truck dies. Could this possibly be the fuel pump going bad?

Tiny
Klay
Mar 1, 2013.
Yes it should maintain 9-11 psi for tbi units. I found this in our tip section though so you might check this out as well.
This tip applies to 1989-1999 Chevrolet GMC trucks with all engines. If the vehicle doesn't start (but cranks), or starts and then stalls, and you have found there is power to the fuel pump when turning the key on for two seconds, which is normal, but no power while cranking the engine or with engine running, the most common cause is a deffective ignition module.

Originally posted for 1995 GMC Pickup C1500 5.0L

Hmac300
Mar 1, 2013.
I have already changed ignition module. Earlier when I tested the fuel pressure again as soon as the truck would die fuel pump would kick on, truck would start again for a few seconds fuel pressure would drop to nothing and truck would die. Why is this just happening in the morning when the truck is cold?

Tiny
Klay
Mar 1, 2013.
Who knows but when cold it's oin open loop try replacing your coolant temp sensor see if that works. Scan for codes aby crossing A& B at aldl below lh side of dash

Hmac300
Mar 1, 2013.
Where is the coolant temp sensor?

Tiny
Klay
Mar 1, 2013.
Should be by the thermostat it will have a black and yellow wire going to it.

Hmac300
Mar 1, 2013.
Thanks I will give that a try

Tiny
Klay
Mar 1, 2013.