2000 s-10 4 cyl

[Truck633]

used to start on first try every time, got to where it will crank for 5 or ten seconds now before it starts. I changed the fuel pump because it was not pushing the required 51 lbs (has 150K on it, it was time) but that didn't solve the problem...Any ideas?

Thanks

Tom

[MT-2500]

Originally Posted by Truck633

used to start on first try every time, got to where it will crank for 5 or ten seconds now before it starts. I changed the fuel pump because it was not pushing the required 51 lbs (has 150K on it, it was time) but that didn't solve the problem...Any ideas?

Thanks

Tom

Did new fuel pump bring pressure up to specs?
51 is a bit high.
What is the engine cranking fuel pressure?

Will it start good with a shot of carb spray in intake.
If so you have a fuel delivery problem.

Any check engine lights or codes?

Good Ac delco pugs and wires and coils?

[Truck633]

Leaning towards crank position sensor, I haven't tried the start fluid to the intake yet, but the way its acting, I think I am on the right track. I have a solid 47 psi during crank so I am going to rule out fuel delivery.
Thanks

Tom

[MT-2500]

Originally Posted by Truck633

Leaning towards crank position sensor, I haven't tried the start fluid to the intake yet, but the way its acting, I think I am on the right track. I have a solid 47 psi during crank so I am going to rule out fuel delivery.
Thanks

Tom

The carb cleaner spray not start fluid in the intake will help rule out fuel delivery problem.

Also check for good hot spark to all plugs when no start.
If good spark to plugs your crank shaft sensor is working.

Any codes or check engine lights?
Is the problem on a cold start or hot start or both?

[Truck633]

no codes, cold start only so far. I can cycle the ign a couple of times and it seems to catch up, after it has been running, it starts right up.

[MT-2500]

Originally Posted by Truck633

no codes, cold start only so far. I can cycle the ign a couple of times and it seems to catch up, after it has been running, it starts right up.

Watch tht fuel pressure when you first turn on key.

Does it build full pressure the first 2 second prime up?
Or do you have to flip the key on a couple times to get full pressure and watch fo fast leak down.
Also try the carb cleaner start test.