93 caprice we weather rev/stall
 

Hey guys wat up?

I've been having this problem for a long time. After it rains/snows extensively my caprice starts acting up. It starts fine, and makes it through a mile or two without any problems. Then all of a sudden as i slow for a stoplight/whatever the engine revs up and down, and continues doing so until it shuts off. I've had the distributor cap replace, also replaced the spark plug cables. Today when my car started acting up i shifted into park-and for some reason the engine corrected itself and ran normally-does that give you guys any clues? I'm really stuck here, i appreciate any help.

I would check all the electrical connections especially the ones going to the computer. It sounds like water is getting in and shorting something out. Is it giving any engine codes?

Sounds like a vacuum leak.

throttle position sensor.

In the late 80's and 90's as more computer controlled equipment came along there are quite a bit of low voltage circuits that contol engine management. I recall in 1989 a neighbor of mine had a 1989 Cherokee Chief. His wife had a problem with it every time it rained hard or she went through a carwash it would run really rough and sometimes stall out. Back and forth to the dealer numerous time. Then one morning I was over talking to him, I was standing in front of the Jeep and he started it up. I saw the smallest wisp of steam come from behind the grill. As it turned out, the engine harness was pinched behind the radiator mount and finally chaffed the wiring. Point being, a slight grounding or bad connection can cause problem that may take a long time investigate. Start with the basics, check all electrical connections, wiring harnesses, grounding straps etc.

Is it a 9C1 or a civi? Are running an L03 or L05 motor? The second question isn't as important, but having owned 3 9C1's, there can be a lot at work you don't realize.

I second the wiring check, especially your ground straps. Shifting into park (next time shift into neutral instead) just takes load off the motor allowing it to correct itself normally. Check your battery cables and ground as well.

I've got a T56'd '96SS and my wife drives a T56'd '94 Caprice Wagon, so I know "a little" about these cars. My first B-body was a '93 OSP 9C1.