96 Silverado Hard Starting

[glbell62]

1996
350,5.7

After putting everything back together after replacing the intake manifold gasket the engine is very hard to crank but every once in a while (4 or 5 start attempts)
it starts perfectly and runs great, but if I turn it off it goes through the same thing again hard cranking.

Is it possible the rotor or distributor is on backwards? (I changed the rotor and am pretty sure I put distrubutor back in same spot but just trying to think of what it might be or would it not start at all if this was the problem.
Would a crankshaft position sensor cause this behavior? I don't have andy code testers but would go get one if this would help diagnose.
I am trying to narrow down the possiblilities before taking it in for a diagnosis.

Any suggestions would be great

Gary

[louisanagambler]

BUY A NEW TRUCK, ITS THAT SIMPLE

[lynntrull]

If the engine is out of timing this will happen. Most of the time when you take out the distributor, even if you mark it, you have to have a scan tool than will display the cam position offset to set the cam position sensor to 0* +/- 2*.

[lynntrull]

If the engine is out of timing this will happen. Most of the time when you take out the distributor, even if you mark it, you have to have a scan tool that will display the cam position offset to set the cam position sensor to 0* +/- 2*.

[ROBERzo]

hi, main is 2001 was too hard to start, I dicovered that fuel pump was not holding presure; just change hose betwin pump and module and is working fine. good luck