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Hey everyone! I just recently got my first old ford, a 1987 f150 5.0 EFI with the 302 in it. It’s all original with a rebuilt motor with 100,000 miles on it. I’ve had it for about 2 months and drove it down from South Carolina to Florida and it drove like a dream. Just recently I’ve run into an issue with It staying running. I will fire it up and it will run from anywhere between a couple minutes to 10 minutes then will just shut off. After it shuts off you can’t fire it right back up you normally have to wait a little while. I’ve done some research and found that the PIP wire is a common problem with this year of Ford. I believe the problem is electrical but I’m far from a mechanic by any means.
Things I’ve done to it:
changed and gapped spark plugs (copper core)
Drained and flushed radiator/ coolant system
Oil change
Went over the fuel system. All fuel pumps work (in both tanks and high pressure one further up the rail)
Had a new electrical harness put on the ignition coil
I also swapped the icm on the distributor and was very careful to mark rotor and distributor placement when doing that with a marker and not fully remove the dizzy just turn it. Could I have created a timing issue doing this, would that cause the truck to shut off like that then take some cranks and time to start again?
I briefly looked at the vacuum lines but I’m not sure I saw any issues there. If it was a vacuum issue wouldn’t the truck be able to fire right back up every time?
I’m very new to this I bought the truck so I would be able to teach myself how to work on cars but this one is stumping so any help would be greatly appreciated. I think I covered everything but if you need more info just let me know!
Yeah the icm was grey and on the side of the distributor. What’s the best way for pulling the computer? Disconnect battery and just unclip any harnesses and un bolt from truck?
Check the condition of any sensors that may affect the fueling of your engine. As the truck warms up, it is going to have different fuel requirements. Check the IAT, TPS, MAP, coolant, and oxygen sensors to see if they are functioning properly.
Do above as well, but you definitely having a leaking caps! Replacing yourself is doable, if you know how to do that stuff. Make sure to clean all old acid off and check all the traces around for continuity. I don’t trust myself with that stuff.
Yeah, that doesn't look good. I have about 40 years of experience in welding, including doing stuff like that, and I wouldn't touch it. I guess it may depend on your pocketbook, but all of that stuff is about 37 years old. I personally would look at getting a remanufactured one.
Do above as well, but you definitely having a leaking caps! Replacing yourself is doable, if you know how to do that stuff. Make sure to clean all old acid off and check all the traces around for continuity. I don’t trust myself with that stuff.
so you think it would be best to get a new ECM? I don’t trust myself with that kinda soldering either lol what would be a good place to find a new ECM?
Check the condition of any sensors that may affect the fueling of your engine. As the truck warms up, it is going to have different fuel requirements. Check the IAT, TPS, MAP, coolant, and oxygen sensors to see if they are functioning properly.
thank you sir I will also make sure to check all my sensors
Yeah, that doesn't look good. I have about 40 years of experience in welding, including doing stuff like that, and I wouldn't touch it. I guess it may depend on your pocketbook, but all of that stuff is about 37 years old. I personally would look at getting a remanufactured one.
10-4 thank you for the input, I’m brand new at this and learning as I go! Any recommendations on where to get a new ECM?
I wouldn't buy a computer until you do more trouble shooting. The computer in it now is remanufactured. They all are.
Get close up pictures of the legs of the capacitors.
What you're seeing on the board might be from the remanufacturing process.
When it won't start, do you lose spark to the spark plugs?
Do you have fuel pressure? You need to check that with a gauge at the Schrader valve on the fuel rail.
When you cycle the key from off to the run position, do the fuel pumps prime for two seconds, then shut off?
Do you have a tachometer in your instrument cluster? The tach should move while you're cranking the truck.
If you're losing spark and the tach isn't moving, that would point to the PIP sensor in the distributor, or the ignition control module mounted on the distributor.
What part number is the ignition control module you put on? Did you use thermal paste when you mounted the ignition control module to the distributor?
What style battery terminals do you have? If you have the ones in this picture, they could be your problem. Also, the two ground wires pictured, need to be connected to the battery negative terminal.
Ground connections that need to be cleaned and replaced if necessary are; the main ground cable from the battery negative terminal to the engine block and frame, the connection near the windshield washer bottle, either on the radiator support or inner fender, the one near the driver's side hood hinge, and one at the ECM behind the driver's side kick panel.
