Intermittant problem 1986 Volvo 740 GLE Stalling out at Highway Speeds

So I’m the proud owner of a 1986 Volvo 740 GLE. About 3 months ago, the car stalled at 70 mph. I noticed myself decelerating on the highway and changed lanes and coasted to a safe stop on the shoulder.



Initially the car wouldn’t start up again. But after leaving it off for a minute or two (it doesn’t need much time), it started right back up as if nothing was wrong, and I didn’t have a problem again for another few weeks until it did it again. It’s died this way on the highway, on surface streets (25 - 35 mph), and most recently this morning, after driving all over the greater san diego area without incident, and arriving back at my apartment, it wouldn’t start when I needed to leave.



I asked my favorite mechanic from back in the Bay Area (when my care first stalled), and he said it could be a relay going to the fuel pump, and that relay was under my fuse holder behind the ash tray.



I’m not sure how I’d Identify a bad relay. but he said thermal expansion could result in an intermittent connection in that relay that would obviously take out my fuel pump when things got toasty.



The car was definitely a bit hot today, but I wouldn’t say the stalling incidents to date really correlate with enormous amounts of heat and aren’t even necessarily preceded by all that much driving.



I’d bring the car to a trusty mechanic, but I know this sort of intermittent problem would be a witch hunt and a money sink.



Maybe with some assistance / description, I can inspect that relay. Anybody got any experience? links to some pictures? tutorials?



One other factoid that is probably worth mentioning. I think my spark plug wires are ones that twist off, and the last place I brought the care to get an oil lube filter / tune up they pulled one off and totally broke it. I seam to recall the employee successfully putting the wire and the part that broke off back together. I figure that boo boo didn’t really kill the cable, and that can’t be my problem anyway. If that wire was the problem, I would be running rough and occasionally missing with that cylinder right? not stalling out at 70 mph and then starting up no prob 150 seconds later.



-Ethan

Well Gollee
sounds like sarvation to me
me me …a fuel/fuel filter check… would be
#1
me me …Vac check… would be
#2 to me me
timing would be #3 but thats just
ME

My guess is that the fuel pump is failing and a failing fuel pump uses more electrical current than a new one.
Over time, more current through the fuel pump relay can burn the contact points and cause problems.

So it’s possible if you replaced the relay you could still have this problem.
About the best way to verify if the pump is going bad is to spray some carb cleaner into the intake when the car will not start.
If it starts up momentarily on the carb cleaner then you can probably figure on the pump being bad rather than the relay.

If it will not do anything on the carb cleaner, then you have to assume an electrical problem; coil, ignition module, ignition switch, etc.

If the fuel pump has never been replaced then it’s long overdue; and fuel pumps can go on and off like this.
Hope some of that helps you out. :slight_smile:

I had a 95 Jeep Cherokee with a similar problem. Very dangerous to drive, especially on expressways with a semi on your rear. I felt like I was putting my life in jeapordy every time I drove (not ot mention the life of others).

After close to $2,000 in replacement parts, fuel filters, pumps, timing sensors, etc., I realized the dealer was just guessing. Next they wanted to replace all the computer items and still couldn’t guarantee they’d solved it. I could have replaced the entire engine for what they charged. I finally got rid of it since how could you tell until it was too late that they hadn’t fixed the problem?

Good luck. I’d say replace the car.

It very well could be the fuel pump relay. If you are going to keep this car then I recommend you purchase a good service manual for it. Factory ones are the best. It will save you a lot of time and money for problems like this and more in the future. Check out Ebay for some good deals on them.

I HAVE A 1990 740 GLE 308,000 MILES LOVE THIS CAR .
BUT (AND THIS ISA BIG BUT)IN THE PAST YEAR ITS ALMOST
GOT ME KILLED SEVERAL TIMES . YES, IT LIKED TO JUST
SHUT OFF LIKE IT RAN OUT OF GAS AT ANY TIME AND SPEED,YES EVEN 70 MILES AN HOUR WITH A 18 WHEELER ON MY BUTT.TURNS OUT AFTER REPLACING THE IN TANK FUEL PUMP AND INLINE FUEL FILTER ,THAT A SMALL SOLDERED
SOCKET ON A TINY PC BOARD IN MY FUEL PUMP RELAY(WHICH IS LOCATED BEHIND MY ASH TRAY)WAS THE CULPRIT