1990 GMC SIERRA 125k TBI 350 starting issue

[1979Lee]

I have a 1990 GMC SIERRA 1/2 ton shortbed stedside With 125k
the engine is the original 350 w/tbi and 700R4 Tranny.
the problem i have with this truck is that when you go to start the engine you have to crank it for at least 5-7 seconds before it will start.
It runs excellent after that but when it comes time to start it same problem.

I have replaced the following parts , fuel pump/sock(old one wore out) and filter, ignition module(old one broke), cap/rotor, plugs ,wires, air filter, tbi to intake manifold gasket,.

when you drive on a long trip oh say 50 or more miles,
you go to start it and bam! starts instantly!

this truck get good mileage for such a large V-8
(18-20+ mpg highway) and idels very smooth.
it does have the ole small block chevy valve stem seal problems and uses maybe 1/4 to 1/2 half quart of oil every 3000k,
not bad for a 15 year old truck that used to tow a 25 ft 5000 lb
travel trailer (previous owner).

Does anyone know why it starts like this?
Is there a way to fix this problem?
Any one else have this problem?

One other thing has anyone elses white paint turn to $#!*
my bed paint is still good but the cab forget it

thanks in advance

1979Lee

[michaelmeck]

as for the starting , every tbi motor I have ever seen does the same thing after about 60,000 miles . they just don't like to be cold. and as for the paint my guess is that the clear coat is gone , I have a 92 and that is what was wrong with mine. It is a common problem with gmc paint.

[2000CAYukon]

I also have a 90 GMC K1500 and yes the paint is in bad shape. No starting problems (yet). Your problem sounds like the fuel pressure regulator. When the engine is off for a while, the pressure is down and it takes some time to build back up.

Try this, next time you go to start it, turn on the ignition but do not engage the starter. Let the fuel pump prime for 5 - 10 seconds and then try to start it. If it starts right up, the fuel pressure regulator is bad.

//2000CAYukon

[1979Lee]

Originally Posted by 2000CAYukon

I also have a 90 GMC K1500 and yes the paint is in bad shape. No starting problems (yet). Your problem sounds like the fuel pressure regulator. When the engine is off for a while, the pressure is down and it takes some time to build back up.

Try this, next time you go to start it, turn on the ignition but do not engage the starter. Let the fuel pump prime for 5 - 10 seconds and then try to start it. If it starts right up, the fuel pressure regulator is bad.

//2000CAYukon

Thanks for all the good suggestions on how to repair this problem.
looks like I will be replacing the fuel pressure regulator.
Thanks again.

[jerradjoe]

Try Looking at the fuel pressure regulator valve