Cold start problem

[borysewicz]

My 1996 s-10 has recently developed a starting problem. Only happens when the truck has been sitting for a long time. Hard to start every morning. Turns over fine but takes several attempts to start. Once started, runs fine, and will start fine unless it sits for many hours, especially overnight.

I'm thinking fuel pump, but this only happens overnight or when sitting many hours. Runs fine after finally starting.

Used to start quickly, every time. Problem is getting worse - harder to start in the morning.

Any ideas?

[MT-2500]

If it is a 4.3 w engine.
Check the fuel pressure on a cold start.
Specs are 60/66 lbs of fuel pressure.
You need close to 65 lbs on starting to squirt the injectors. If it is below 60 lbs it will not start good.
MT-2500

[borysewicz]

Thanks, MT.

How difficult is checking fuel pressure to do? I assume low fuel pressure = replace fuel pump? How difficult is it to replace the fuel pump.

[MT-2500]

You will need a fuel pressure gauge and a adapter th fit the test port on the fuel rail.
The test port on a 4.3 is on right rear of engine by dist.
If fuel pressure is not in specs. Check direct fuel pressure at fuel filter to see if fuel pump is weak.
They can lose lose pressure inside plamtuim or at fuel pressure regulator.
So check direct fuel pressure at filter. It should have over 20 more than specs if the fuel fump is good.
MT-2500