2.1 dies after 40 minutes in extreme heat-SOLVED

[Howesight]

Hey Dave:

Here are my suggestions:

1. First, replacing the fuel pump is an excellent idea as preventive maintenance. The symptoms you have could be a failing fuel pump, but in my view, this is HIGHLY unlikely. When they die, they can give out and come back to life a couple times, but not as many times as you have found.

2. Most likely culprit is the ignition coil. Heat affects the windings in these 25 year old units. Not an expensive item. Also good preventive maintenance.

3. ECU: the ECU interface with the wiring harness is a portion of the printed circuit (PC)board itself. Over time, the twisting force on the connection can crack the PC board and the copper traces on it. Heat expands the gap. A quick fix is to turn the ECU 180 degrees around so the twisting force is applied in the opposite direction, thus closing the gap. The quickest test is to temporarily substitute a borrowed,known-good ECU and check for symptoms.

The most tell-tale sign that the ECU connection is your problem is if, when the symptoms appear, you see the tach needle violently swing up and down.

4. Hall sensor: the wires are not well-supported on these little units and damage to the wires sometimes occurs, causing the problems you describe.

Good Luck!
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'86 Syncro Westy SVX

[davevickery]

So I think this mystery was solved.

Here was my original description of the problem: "My van runs fine for 30 minutes or so then looses all power and if I pull over, it will idle for a minute before dying. Running it on the highway or around town doesn't matter. Won't restart right away but waiting a few minutes it will start right up and run for a few minutes before dying again. Waiting a half hour, it will run for 15 minutes. Overnight it will run well for 30-40 minutes again. It is obviously fully warmed up long before it starts to stall out. It has suddenly gotten much worse. Does anyone recognize these symptoms." O

Things it wasn't: 1) I opened the AFM and moved the board the wiper swings across just a hair so it would be making contact on a fresh path. No Difference.
2) Replaced FP regulator with a used one I had. No Difference.
3) Installed new fuel pump relay for $9. Replaced fuel filter (regular maintenance anyway). No difference.
4) Cleaned contacts on Hall sender connector, checked and cleaned up grounds. Nada

Turned out to be a failing fuel pump. $109 from Busdepot.

[mtwrench540]

splain how pressure can be resonable when testing quantity??just had same problem on 2000 exploder,pump wa only 2 years old,now have bosch life time from advanced auto!
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87 wolfsberg,74 181w/1915 and lots of patina! learned to fix vw's from hot vw mag in 1964,VWOA instructor,DSM,69 to73,service mgr at different porsche-audi dealers etc,etc,now retired!!! first vw new 64,transplanted 356 eng in 65,400characters are not enough space!!