grumpymatt

My 2001 Express LT with the Vortec 5.7 won't start. Was driving fine last weekend and suddenly won't start after sitting for 5 days. I check spark plugs, it has spark. The plugs were also wet with fuel. Fuel pressure is good at 60 psi. I tried using starting fluid, but it backfires badly and still doesn't start. The fuel pump was changed about 15k miles ago, and I think the distributor was done about 30k ago (before I got it). It seems to be getting fuel, spark, and compression, all I can think of is the timing is somehow wrong. I have a hard time believing the timing chain skipped, because it ran fine when it was parked. I think I'll try a new distributor. I also considered getting the MFI conversion, but it seems like it's getting fuel so not convinced that will fix it either.

Anyone have any other idea's?

Irish_alley

bad or weak camshaft position sensor

canucklehead

Clean under the dizzy cap. The 8 points get oxidation on them. Rotor too. It may have spark, but maybe not all 8, and it may be weak.
Have you checked for codes?

grumpymatt

I looked under the cap, it looked pretty clean. Spark looked strong on the 2 cylinders I checked.
No codes.

I could try the camshaft position sensor. Does it control timings?

canucklehead

If no codes then its had to assume its a sensor. The crankshaft and camshaft position sensors both give info to the computer for timing.
I would pull all 8 spark plugs. check the gap, (are they iridium)? worn plugs can cause hard cold starting, and misfires.

Iamchevyvanman

My old 2000 with the 5.7 was a very reliable van but I do remember at one time I had an intermittent problem, (not no start usually) but it would run fine and then all of a sudden it would run terrible and wouldn't go when I gave it gas and later it would run fine again. It actually had my mechanic stumped for a while too but it was a sensor problem, that's what I think you are having also. I think mine was cam position sensor.

grumpymatt

I replaced the distributor and that fixed it. The Cam position sensor is in the distributor, so not sure if that was it, or if it just needed a new cap and rotor.