stalling in high humidity?

Question

1991 Dodge Caravan 4cyl 2.5 runs good except when it is really humid. Then it will die. it will restart, but won't stay running if you press on the gas or put it in gear. But if you let it sit for awhile. It will start up and run perfect.

Answer 1

The only thing that comes to mind is that maybe you are getting some condensation inside your distibutor. Have it checked out. Hope this helps.

Answer 2

Two things I'd look at:

1. Make sure the air filter is relatively clean and not ancient and full of dirt.

2. The throttle body might need cleaning. The oil and gasoline vapors from the PCV and breather hose will accumulate in the throttle body on the engine side of the throttle plate. This restricts air flow and can lead to stalling or a rough idle. You can clean it with a clean rag and a can of throttle body cleaner. Just hold the throttle plate opne and spray and wipe the goop out until the rag comes out clean and you see aluminum where there was once black sludge.

When an engine gets old the compression is not like new and the thinner air can throw off your fuel air mix and since compression is lower it will make the engine run odd or stall in higher temp's.

There are temperature sensitive sensors in the engine and these will often behave like the engine is already warmed up and you might start the car with the sensors adjusting the timing and fuel air mix on a cold engine rather than a hot engine. The way it usually works; the "loop" closes when the engine gets warm or hot and the computer or brain box takes over the engine functions If it is already 80-100 degrees outside these sensors will close the loop sooner than is typical and if your car is parked in the sun it will already be hot or very warm.

There are some things that you have to work around on this planet and extreme temperatures is one of them. In the Sinai Desert the helicopters (Hueys) cannot fly at temperatures higher than 110 degrees for fear of "stalling" meaning the air is too thin to support the weight of the aircraft in flight and even at maximum power it might not have sufficient lift to be safe to fly or haul troops around.

Good Luck!

Answer 3

Your question stirs awful nightmares for me. I had a 4 cylinder 1995 Caravan. Biggest piece of shiit I ever owned. However, I digress. I would suggest one remedy would be replacing your spark plug wires. The reason is that humid air is a better electrical conductor than dry air. If your spark plug wires are old and cracked, they can crossfire, meaning that the electricity jumps from wire to wire instead of traveling all the way to the spark plug and firing there. This happens more readily in humid air. You can see the sparks jumping around between wires if you open the hood at night in the pitch dark. Your engine will run like crap or not at all if this is occurring. I had this problem on an old Datsun, and I could not for the life of me figure it out until one dark rainy night it wouldn't start and I opened the hood and had my dad try to start it, and sure enough I had a fireworks show going on under the hood that would have put July Fourth to shame. Now mind you I am not suggesting that this is the only reason a 4 cylinder Dodge Caravan will stop running. Mine stopped running for much more serious reasons. Let me know if you ever have problems with cracked heads, blown head gaskets, corroded water jackets, water-filled cylinders, oil leaks, blown fusible links in the starter, overheating, and other assorted issues. These are just some of the reasons my Caravan is in a landfill with barely 60,000 miles on it.