2002 Eurovan stalls after climbing hill on hot day

[barkleybeast]

Our 2002 Eurovan with 186k miles developed a problem earlier this past summer. It stalls after climbing long hills on hot days. The stall occurs only if you slow down - if you keep it reved up it does not stall. It doesn't want to restart when this occurs - just cranks and cranks. Let it sit for 15-20 minutes, and it starts and runs fine again. If you're in a hurry, you can keep cranking and pumping the gas pedal, and eventually it will catch, and if you keep it reved up you can get it driving again, but if you let it drop to idle, it stalls again. Also, we noticed that when it stalls like this, the radiator fan does not run. It usually runs for a few minutes on a hot day if you shut it down normally. The dashboard coolant temp gauge always reads the same normal temp in these situations.

We had a shop replace the radiator temp sensor and both O2 sensors, since this felt like it might be a hot day rich/lean issue, and because we had gotten some O2 sensor engine codes, but that didn't fix the problem. The problem is almost impossible for a shop to reproduce, because it has to be hot, and you have to drive it for a long while up a steep hill.

A couple years ago we had the cam position sensor replaced after it failed, but this doesn't feel like that problem.

Of course, after it stalls, it takes a lot of muscle to steer and brake, so this is more than just an inconvenience on a windy mountain road.

Any ideas as to what may be causing this?

[ach60]

Air, Fuel, Spark.
My guess is you're starting to loose your fuel pump.
Set up a way to test your fuel pump pressure, at the time of failure.
You'll find your fuel pressure has dropped to the point you're not getting gas enough to run.
May be pump(s) or relay, or harness may be damaged, so test, don't throw parts at it.
_________________
Good Luck
Al

[Abscate]

Al is right on point. Fuel pressure test under conditions of failure. You might get some indications with a cold fuel pump test not Meeting spec but a false negative can’t be ruled out
_________________
.ssS!