1987 F-250 loses power after 10 minutes while driving


#1

5.0L V-8, Electronic Fuel Injection, 79,000 miles, 2 WD, 4 speed manual. I’m the original owner.

If I drive it 4-5 miles on secondary streets (25-40 MPH) it shuts off without warning after 10 minutes and will not restart without a 20-30 minute wait. If I drive it 2-3 miles and park it for a couple of minutes it will not restart without waiting 20-30 minutes. Checked engine water temp gauge and it is normal.

The local mechanics found no spark when it failed at their garage. They replaced the ignition module on distributor. This did not fix the problem. In their second attempt they replaced the coil. Still the same problems persists and the mechanics are stumped.

It’s like something in ignition package heats up after 10 minutes and either sticks open causing no spark or closes shorting out the spark if that is possible.

Any ideas on what is causing this and how to fix it. Thanks – Glen


#2

If the ignition module and coil were replaced and there’s still a shut-down problem, then it’s time to check the distributor pick-up coil.

http://www.rockauto.com/catalog/moreinfo.php?pk=951144&cc=1124097

Tester


#3

How about the crankshaft possition sensor @Tester.

Yosemite


#4

The magnetic pick-up is the crankshaft position sensor.

Tester


#5

In the event the problem turns out not to be related to the distributor pick-up you might consider a failing ignition switch; or at least the electrical part of it.

I did not pull a wiring diagram for your truck but many Fords run their cabin blower motor current directly through the switch. The blower draws a lot of current new and much more when aged and worn.
That current goes through the switch and overheats it which then leads to intermittent stalling or no-starts. In some cases the plastic case of the switch can appear to be melted.

I tend to agree with Tester so I’m just putting the switch out there as a possibility. If the truck stalls it’s easy enough to check by testing for voltage at the ignition coil; the red and green wire if my memory is not too fuzzy… :slight_smile:


#6

Thanks Tester and ok4450.

I’m lucky to have another auto repair service center nearby and have an appointment for Monday. I will give them a print out of all suggestions received.

The original mechanics gave up and suggested a trip the nearest authorized Ford Service Center which is 8 miles away and involves a drive on a very busy interstate. This truck is not road worthy so it would need to be carried.

The ignition switch is something I did not think of. However the truck has no A/C and no heater fan turned on in the summer; still something to look at.

Also received a suggestion it is a distributor stator located inside the distributor that is the problem; any thoughts on that?

Thanks again – Glen


#7

Since the mechanics already discovered a “no spark” condition, that’s good news. This should be fairly simple for an experienced mechanic to diagnose. They just need to go though the whole electronic path that makes the sparks is all. Checking each component. On a 1987, there may be more than one component that is failing. It could be any or all of the parts mentioned above, but I’m guessing the most likely culprit is something associated with the crank (or in a 1987 it might be a distributor cam) position sensor.


#8

Just to follow up on the truck problem; I took the F-250 to a second repair service center. They replace the pick-up coil or stator as it also called as Tester suggested on Friday. I have taken the truck for two short runs and have experienced no problems. I think the problem is fixed!

Ironically this auto repair center is just across the street from me and is run by one mechanic and his extremely knowledgeable wife. She has auto shop knowledge like the Mona Lisa Vito character (played by Marisa Tomei) in the movie My Cousin Vinny. I noticed they work on a lot of older and classic cars and should have went there first. They also have great rates.

In addition to the stator they found 5 of 8 connection points in the distributor cap were corroded and replaced the cap. This had caused misfiring for about 5 minutes at start up after extended rain storms; a different problem. The distributor rotor was also replaced.

The original service center I took the truck to has a great reputation and has a number of certified young mechanics but they failed four times to find and fix the problem. They could only recommend me going to a certified Ford service center miles away and that was not a good option for me.

Thanks to all who responded.


#9

You need to add the service center to the “Mechanics Files”. This will help others get the same great service you got and help the shop too. Nothing like word of mouth to make a small business successful.


#10

Just added them. Five wrenches, Rich’s Service Center, Groton CT