Car questions


1999 GMC Jimmy, only 65,300 miles, had the rocker sensor replace, injection fuel replaced, but, every time it rains it will not start. After it stops raining (stays in a garage, never out in the weather) and the sun comes out then it will cranck after a day or so. It does not have a cracked distribitor cap. My repairment is stumped, the GM rep is stumped and I am tired of paying a towing fee. Anyone else had this problem and how to repair? It is getting to be the rainy season in northern Louisiana and I dread going out every day not knowing if this car will start or not.


I’ve never heard of a rocker sensor. But the problem is almost certainly electrical and not fuel injector related. If I’m interpreting your post correctly, the engine doesn’t even crank when it’s raining. That would send any tech straight to places like the battery cable connections, the battery terminals, and the starter circuitry.

This needs to be diagnosed hands on, but it isn’t rocket science. It’s pretty basic diagnostics. I’d suggest trying a different shop.

Sorry, I wish I could provide a more specific answer.


You probably mean the “knock sensor”. This is part of the engine management system controlled by the car’s computer. I suspect whoever fixed it did not do a proper diagnosis or repair job. Find a reputable garage specializing in tuneups (they will have a powerful diagnostic computer)and I’m sure they will find the problem. Your GM folks are giving you a snow job. Most dealer mechanics work on nearly new cars and any weird problems they deal with usualyy have a factory service bulletin explaining how to go about it. Dealer staff ALMOST NEVER deal with vehicles like yours (age-wise) and don’t know how to diagnose vehicles with substantial miles on them. When I had a 1988 Caprice with an electronic carburetor, the dealer was the worst place to go. I patronize a shop where the owner rebuilds cars of all vintages and only employs first rate mechanics.


Sounds like you need new spark plug wires. Bad plug wires are a common cause of wet-weather starting problems.

Usually this affects cars sitting outside, but if your vehicle’s plug wires are old and dried out, it could be the problem. Hard to imagine a mechanic has not already replaced them, though.


You may have moisture inside you didtributer,or on you sparkplug wires. Open the distriguter cap and use a hairdryer to dry it out. You may get lucky. GOOD LUCK! nICKR1932@YAHOO.COM