My ex drives our kid around Maui in a 1990 740 GLE (non turbo) and it's been stalling at the most inconvenient places and not starting for say, 20-30 minutes (then it seems to run fine, at least for another 15-20min. Our savant mechanic with an inherent drive to sleuth out problems is stumped as to why this intermittent stalling is going on. This seems to be happening when it is warmed up, first did it the after "acting funny" in 4th of July bumper to bumper traffic over in Lahaina, when it got to it's destination, it crapped out in the driveway.

Then, it stalled coming home the next day (fortunately right by beach park), a hot day, so I went out to get here a tow. Got rope on, it starts. Take rope off, realize I killed my battery in my Subie Outback while I was fiddling around with the 740, so she pulls it around to jump the Subaru, and it craps out again. So, we get someone else to jump Subie, I turn around to tow her and we go about a mile, tow rope snaps after crest of hill, but, 740 starts up and makes it back to Pa'ia (about 12 miles from that point).

Next day, mechanic looks at it, starts fine. No problem is reproduced, so hard to diagnose. Tonight, it stalled out again and started right back up a couple times during the day, then really stalled out turning onto the busy Hana Hwy from Baldwin Beach, thought I was going to tow her again, but 20 min later, it starts back up. So, for the second night in a row, I follow her home, but tonight it stalls out when making tight turn uphill to get to her neighborhood. So, I manage to tow her up and over to her place. (Accidentally took off front bumper when hook slipped, but I got it back on). And, of course, it starts right up.

Some background:
-fuel pump relay has been tested and is working.
-a couple weeks ago two of the injectors were replaced (or fixed, not sure) after we thought it was really going south (oil in plug cylinder, power loss).
-spark plugs replaced at same time injector issue was being assessed.
-fuel pump and filter underneath were replaced last year. (could it be other fuel pump inside tank?)

This is driving me nuts! Every time I turn around this thing is stalling! Help!

 

Assuming that all the recent repairs are above suspicion, which is never a certainty, I'd look at the Crankshaft Position Sensor (very likely culprit). Then I'd look at the Radio Suppression Relay.

Not too clear on the "injectors and oil in plug cylinder" but that should not cause stalling.

 

DOES YOUR TEMP GAUGE GO UP OR STAYS IN NORMAL RANGE?

IF ITS OVERHEATING YOU GOT A HEAD GASKET PROBLEM OR COOLING SYSTEM FAILURE

OIL IN PLUG? you mean freeze plug or on one of the spark plugs?

Is your distributor on the back of the cylinder head? pop it open and see the condition of the cap and rotor and if there is any oil there.....

 

Typical fuelrelay problem. Heat causes the solder in the relay to crack and malfunction. After cooling down it works fine.

 

Where is the Crankshaft Position Sensor?
We dealt with the Radio Suppression Relay, when I noticed the wires off it several months ago. When that was off, the thing wouldn't turn over at all.

No, I don't think the oil that was on the spark side of the spark plug cylinder is causing this. Two of the injectors were not working correctly and were replaced about 3 weeks ago. It ran pretty well until Friday last.

Distributor checks out ok.

(and it's not overheating and no oil in coolant, I don't think we're dealing with a HG)

 

Crankshaft Sensor ( http://www.autopartsnetwork.com/volv...ensor/ava4J6PZ ] lies between the engine and the gear box. Follow this wire from the fender wall down to the engine and you will find it. Its easy to change but its difficult to reach/get to down there. Be careful when taking out the sensor as you could easily damage the connection point.