My 1996 Dodge Grand Caravan has developed a curious problem. It intermittently stalls, sometimes when slowing down, sometimes when going up an incline, sometimes on straightaways. Once stalled, it often won’t start again until it has sat for 20-30 minutes. Then it starts right back up again and drives perfectly normally until the next time that it stalls-which can be days or hours. The problem is definitely getting worse–six times today. Warmer temperatures seem to exacerbate the problem. Again, the engine runs very smoothly up to the point of the stall. My mechanic was unable to replicate the problem and his diagnostics showed everything to be normal. Any ideas?
Possibly a failing fuel pump. Go back to the shop and let the vehicle idle in the parking lot. When the pump gets hot the engine will die (should take less than an hour), go get the mechanic and show him. He can put a fuel pressure gauge on the vehicle to check the pump operation. If it’s not the fuel pump at least your in a parking lot and not on the road.
BTW if the fuel filter has never been changed the restricted flow will shorten the life of the fuel pump.
Along the lines suggested by Nevada_545 you could do a sort of half-baked “test” for an overheated fuel pump on your own. Get 5 gallons of fresh gas in a can. Leave it someplace shady and cool (as you always should with a gas can anyway). The next time you’re down under 1/4 tank or so, idle the van until it stalls. If it won’t restart, dump the 5 gallons of cool gas in there and see what happens. I would try this b/c I’d rather figure things out & fix them myself. You might prefer just trying out the shop parking lot.
Another thing to worry about on this van is the “Auto Shutdown (ASD) Relay.” The relay itself might be bad & shuts the van down when it gets hot. Or you could have some other issue that is telling the ASD relay to do its thing.
When it won’t start for 20-30 minutes is it cranking over just fine, but just won’t fire up? In other words - what exactly happens when you turn the key?
Turns over just fine - starter sounds great - nice and fast. After sitting for a bit, you can turn it over a few times and nothing happens. Then, the next time - it starts immediately.
Simple test for a bad fuel pump, or to eliminate the ignition system as an issue. Buy a can of starting fluid… Next time this happens, spray some starting fluid into the throttle body… If the van starts for a moment then dies, your ignition is fine, and you have a fuel issue… Let us know what happens.
I took the Voyager to my mechanic on Friday, May 11 - he idled the van for four hours - no misbehavior. Tested the fuel pump - no misbehavior. However, the senior tech made a case for the crank sensor relay being the culprit - essentially, that relay, when it overheats on higher-mileage vehicles, no longer gives the signal for spark to travel, effectively shutting down the ignition system. Once it cools, it fires up again. Since that argument matched my symptoms, I gave the go-ahead for replacement, and so far, so good - three days of driving with no shut down! Thanks for the tips, everyone.