I got a 97 s10 with a 4.3 and when its get humid out it wont start. its got new cap,roter,coil and ingition moduel.
Its got fuel pressure or i can dump gas down the throtle body and wont start.
i pulled #1 wire and put a test light in and theres spark but no start. 2 other thing i was thinking was crank positioning sensor and the distributor body.
it just wont start when its moist/ humid out.

 

Did you put plug wires on it?

 

On a dry day when it will start you could spray individual components/areas with a spray bottle of water to help locate the problem area. Also could try running it at night with the hood up to look for arcing. Be careful touching components when it is running, if it is leaking secondary high voltage and you touch it you will get shocked.

 

Try this forum.
https://www.s10forum.com/

 

You mentioned that you replaced the module, cap and rotor. Do you still have your original module? If so, I'd go back to it. You can always have a module tested at the auto parts store.

Also, make sure you use thermal paste below the module. You can get this on Amazon.

https://www.arctic.de/us/products/co...l-pastes-pads/

 

Lars,
I don't know about the 4.3's but in those years the 5.7's are notorious for the distributor caps causing problems and AC Delco caps and rotors being the only ones to use.
Also like Sugar Bear said try misting it with a spray bottle at night. Even better if you can get someone to sit in it and power brake it to get a load on the engine.

 

the plug wires are newer replaced a few years ago. i will try other sugestions thanks guys