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2002 Chevy S-10 won't start when wet

I have a 2002 chevy s-10 pickup, 4.3 V6 vortec, 4 wheel drive. It has developed a crank-no start when it’s wet outside. Snow, rain, even high humidity.

Things already done: cap/rotor/wires/plugs; coil; fuel pump (fuel psi between 45-55). There was an issue with the distributor being chewed up by the cam - cam gear was inspected and is supposed to be in good shape. A used distributor was installed by the local shop. Engine has 200,000 miles. I was told the timing chain is a bit stretched but there is no timing problem.

When it is running, it purrs like a kitten. Good power, smooth idle, no smoke and there is no engine codes generated by the crank-no start problem. I have power to the coil when it’s happening, fuel in the system, even have a spark out of each cylinder wire but it still won’t start.

Anybody out there have any idea? I think the car is possessed!

The next time its dry out and the truck is running, idle it while you mist the crank position sensor with a water bottle. See what happens.

The fuel pressure reads 45-55 PSI? That’s too low. You should be seeing something over 63 PSI.

You have the infamous GM Central Port Fuel Injection system. And how this system works is, there’s a central fuel injector under the intake manifold, and from the central injector are tubes that run to each cylinder. At the end of these tubes are what are called popet valves. These popet are forced open by the fuel pressure to inject fuel into the engine.

Go back and recheck the fuel pressure. And if it’s below 63 PSI, you need a new fuel pump.

Tester