Working on my daughter’s 1999 Chevy express van 5.7L. It has a intermittent no start problem. Over the last 3 years I have put 3 crank sensors on it. It also has a new distributor cap rotor plugs new injectors fuel pump filter plug wires coil & module. This time the only code it shows is a P1336. Crank sensor needs relearn. That has never come up when I previously changed sensors. I replaced the sensor plug in and it has 12v with the key on has a ground on middle wire and 5v signal on last wire. With the three previous sensors there are no marks on it from the ring. As far as I can see the ring is good when turning it by hand. When it does not start it has 45lbs of fuel pressure and plenty of spark. Tried to do relearn but when you get it to run you have to turn it off and restart but it won’t restart. I don’t think the relearn would keep it from starting all the time. Any help would be appreciated. Thanks in advance for your time.

 

These vans have an issue with the distributor internals as well as the cam sensor harness going to the distributor. Moisture build up. Check the wiring going into the electrical connection of the cam sensor. Mine had corrosion of the wires. Hard starting would show up for me on rainy days. Replaced the wiring connection and all has been fine.

 

thanks for the help. It has a new GM distributor and I checked it recently and rotor & cap look new. I will check the harness. This thing will start every now and then. When not starting it has 50 psi of fuel and plenty of spark. I am now leaning to the passlock system. Waiting for a new bypass module. Something new it started yesterday, with the key off and out the relay for the fuel pump keeps clicking. I know because my fuel gauge I have hooked up to the rail keeps jumping. I have to disconnect the battery to stop it.

 

I just recently replaced the key lock assembly in my wife's 2004 Silverado and had the problem you are concerned with. I found a youtube video that fixed the starting issue. Simple and easy fix.