1999 gmc jimmy will not start after it rains?


#1

I have taken to mechanic- no codes, all reads well. have changed fuel filter, checked fuel pump, spark plugs, battery fairly new. after it rains, it cranks-engine shakes-wants to start but wont. Almost like gas or ignition will not kick in. if sunny, ok- This only happens after it rains- Any ideas or if anyone has experienced this, it would be much appreciated.


#2

Might have a bad coil wire


#3

Put in a new set of spark plug wires. This is a common problem. Old plug wires become porous or crack, moisture from rain gets inside and shorts the wires out. Then car won’t start in rainy weather.

You can verify by waiting until dark, then open the hood. Use a spray bottle to spray some water mist on the old ignition wires. Then have someone else crank the engine. You may see arcs as the wires short out due to the moisture.


#4

Agree with @jesmed1 since a new set of plug wires usually fixes this problem.