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1998 Chevy Blazer no start in rain or damp weather

I am a laid off mechanic doing some side work. I friend of mine has a 98 blazer that will not start in damp weather. Here’s the kicker, it has spark to the plugs. New cap, rotor, pick up coil, and wires. Fuel pressure is around 60psi. I think it might be in the fuel injection. I drove the SUV into my garage, While the engine was running I watered the distributer down along with the wires. It ran fine. I shut it down and tried to start it a few mintues later with no luck. I took the distributer apart to inspect it for water and found nothing. I reassembled it and still had a no start situation. I am running out of ideas. Anyone experience this before? Or better yet fixed this before? He had it to a few other shops and they could not figure it out.

Have the wires and plugs been changed at any time? The wires may be arcing through the boots when the wires are installed and close to the cylinder head. Wet conditions may make this worse. Also, has anyone checked the coil for cracks?

The wires and plugs were changed recently. The coil looks good. I crank the engine for 30-40 seconds and run to smell the exhaust for gas and there isn’t a gasoline odor. If the engine lost spark the exhaust would smell like fuel. I hope the neighbor were not watching, you might see me on “My Strange Addictions” lol

If your suspicions about the fuel injectors is correct, you should be able to use a mechanic’s stethoscope to hear if the injectors are pulsing. OR a long screwdriver for the poor man’s stethoscope.

Not as easy as you think. It has the internal spider injector system. It is inside the intake manifold.

I’m assuming the truck runs fine otherwise.

It sure seems like a high voltage electrical problem to me. I’d exhaust all the possibilities there first, before going on the fuel system. Sometime you have to completely remove the coil, put it on a table, and clean it off with soap and water before you can see a crack. The crack can be so tiny it is almost impossible to see. I had a similar problem with a VW Rabbit years ago, and I sprayed water all over the engine, and it would run fine. The first time it rained, it would stall. When I removed the coil I found the crack.

Have you check for carbon tracks on the inside or outside of the distributor cap?

Does the ignition system use a separate condensor? That’s a possiblity too. You might try replacing it.

If your car has a capacitive discharge ignition system, that could be the problem. Those don’t take well to dampness. Usually you have to replace the whole module.

If the problem is in the fuel system, my first guess wouldn’t be the main injectors. You can listen to them as posted above, but I doubt doing so will tell you much. My first guess in the fuel-system would be the cold-start injector. It is supposed to inject some extra gas if the engine coolant is below a certain temperatrue (usually around 90-100 deg). Perhaps something is failing and it isn’t doing it’s thing, which would make the engine hard to start in colder temperatures. Add dampness to that, and it might indeed not start at all.

Best of luck.

“I friend of mine has a 98 blazer that will not start in damp weather. Here’s the kicker, it has spark to the plugs.” I assume that means it has spark to the plugs when you checked it. Was it in a no start mode at the time? Until you can replicate the no start mode you are chasing ghosts, Try an approach of a spray bottle of water when the engine is cold to the wires etc. to see if you can replicate the problem, or check it out when the no start problem occurs. Really sounds like electrical problem rather than fuel problem to me.

I didn’t take to coil off but I did give it a very good soaking while the engine was cold. I also soaked the cap and wires. I soaked a module near the coil, not exactly sure what it is, it has a nice sized heat sink on it. Engine starts each time with those items soaked. There is a slight backfire each time I do start it. I’ll go out and try to start it again in a few minutes. Perhaps the water needs to soak in? I didn’t use a garden hose this time I used a Windex bottle with water in it, so I can focus on individual items.

Next spray down the crank position sensor & see what happens.

Does this thing have that terrible, useless, trouble prone GM Passlock system? If so, what’s the little red light doing during a no start?

Just replaced crank position sensor this morning with a new one. Started the engine ran fine. I hose down the engine and now it will not start again. So the run down is new cap, rotor, cam position sensor, crank position sensor, wires, plugs. It has spark, but I can not be sure if the spark is at the right timing. Once is a while it will back fire or kick. The engine will abruptly halt as I am turning it over, as if the plug is firing out of time and fighting the starter. I did spray starting fluid in the intake and it does not help. I’ll check on the Passlock system.

Passlock system seems to be fine. I relearned the crank sensor and it appeared to run fine. I did notice something after hosing it down again. The fuel pump doesn’t always run. I cycle the key and i did not hear the pump, I turn the key off and the pump cycles. I don’t know if the Passlock has something to do with that? I need to track down a wiring schematic.