1990 928 GT - Failure to start following rain...

If there is too much fuel for the car to start, pulling the fuel pump fuse will stop fuel delivery. When you then try to start the engine, if it tries to run for even a few seconds, you know that the problem is too much fuel. You haven't mentioned trying this...

Will do. Thanks fellows! Now I have to wait on it to rain, so it will fail again, so I can test it with your steps. Will post results afterwards.

I cant remember reading if you tested for spark when it would not start?

Have you thought of the crank sensor?

you could wiggle it and see if that changes anything or even warm/dry the sensor and wire with a hair dryer just to tray and eliminate what it is not.

The crank sensor has caused many a dead cars and it is exactly in the wrong area to get moisture.

in this picture the little round knob at the top is the bottom of the crank sensor that it pushed down through the bell-housing.
so this should help you understand that it is under the air cleaner at the very back of the motor right around that throttle cable pulley plastic wheel

So it happened yesterday morning again. So I tried the things you fellows recommended.

First I pulled the fuel pump fuse and it made no difference. It just turns the starter over, with no fire at all. So I put the fuse back in.

Then I pulled the air box and sprayed starting fluid onto the air filter. No change. Same symptoms and no start.

About 6 hours later I went back out there, & it cranked right up. Man, I am really frustrated.

Kent, it didn't even hit off the starting fluid?

Frankly, I need more info. Did you depress the gas pedal to the floor when you tried to crank it over with the fuse pulled?

Assuming there wasn't an excess amount of fuel in the engine, it is probably safe to assume that you don't have any spark. You need to remove two plug wires, one from each cap, and check for spark with the instructions I posted before.

Go to the parts store and rent a NOID light. You need to check your injector pulse simultaneously. Report back and be descriptive.

Not at first. I let it turn over with no pedal at all. Once it did nothing, I pressed the pedal to the floor and held it. No change. I smelled fuel strongly afterwards when I opened the hood, but it could have been from before I pulled the fuse.

I have spark tester and NOID light sets. Unfortunately, working on these cars for several years has forced me to stock my toolsets pretty well. Will let you know what they show, on next failure point.

Thanks for the help Austin.