I posted this in the 87-96 subforum but I was told to try some of the other subforums for this question.

I recently picked up a 1987 Ford F250 XL and have had a series of pretty irritating issues. When I first picked the truck up, it started right up and I drove it about 20 miles before putting some gas in. Keep in mind that the gas gauge does not work (more on this later). After fueling up, the truck would crank but not start. I pulled the air cleaner off and found that there was a substantial fuel leak right at the fuel filter up by the carburetor (this is a 460 with a Edelbrock carb). Needing to get the rig home, I primed the carb and she still didn't want to start. After several minutes of trying, she finally started up and I got her home. The next day she starts right up in the morning and I head to work. On my lunch, I go to head home and she just cuts off when I shift into 4th. I coast into a nearby parking lot and once again she just cranks and cranks but no start. I remove the air cleaner again to find that the aforementioned leak has become massive. I immediately replaced some of the hose as well as the fuel filter and got that leak taken care of. But still no start, no even when priming the carb with gas or starting fluid. She would just crank and crank, sometimes sputtering a bit but then dying. The weird thing that happened that made me think this might be have been a fuel related issue was that she would start for a second if I played with the tank selector switch while cranking the truck over, but no matter what she only started for maybe 10 seconds before dying. I got pretty frustrated and I had also flooded the carb by this time so I got a ride back to work and decided to take a look after work.

I come back after work and try to start it and she starts right up. The idle was pretty rough but I took this opportunity to get the truck home. I turned the truck off and decided to clean the carb up a little bit. After a while I had my girl start the truck up and it ran for about 1 minute before cutting off. No sputter or cough, just a clean cut off. That's when one of my buddies mentioned replacing the Ignition Control Module, located in the drivers side fender well. I went to the parts store and got a replacement (yes the color codes matched) and also got a replacement ignition coil. I took out the old ICM and noticed several holes in the silicone that the chip is inside of (I will attach pictures). I put both of the new parts in and the truck started right up and there was a noticeable improvement in acceleration, however the idle was still shaky and unacceptable. I figured I had taken care of my problem but boy was I wrong. I drove the truck about a total of 25 miles the next day before I started having the issue again. This time I had parked it at my work and it had sat for about an hour before I went to start it. When I started it, it was idling at about 500 rpm and very shaky. It ran for about 45 seconds like this and cut off just like before. Frustrated, I opened the hood and could see that the fuel filter was full of fuel, so I decided to unbolt the ICM from its spot and look at it. I noticed a small pinhole had appeared above where the white wire goes into the silicone on the back of the ICM. I then tried starting the truck again and it started right up.

It has not done anything questionable since, but this was just yesterday. I need to know what could be causing those holes in the silicone or if that is just normal. Also, could this actually just be an intermittent fuel pump issue? This truck has the dual tanks with low pressure electric pumps in the tanks. My gas gauge doesn't work and I think that is due to the replacement fuel tank selector valve either being faulty or not wired in correctly. I know that flipping the switch kicks the pump on for whichever tank is selected so I am thinking that this could also be a fuel pump issue or something wrong with that valve or switch. I want to bypass the valve for now but I don't know what to do for the wiring side of that task. This is my only vehicle right now and I am really regretting this purchase but I need to get it figured out. Anywhere in particular I should start looking? Anyone else had issues like this? Any help would be greatly appreciated.

Here's a photo of the old ICM. Note the several holes that look like they melted the silicone:


And here is the new one after 24 hours of use. Note the small hole that has appeared above the white wire.

 

First off, you do not know if you have a spark problem or a fuel problem. When it won't start, you need to know if you have spark or not. Go to Harbor Freight and buy one of these. Plug it in when the truck is running and get used to what it does and what the spark looks like when it is running. Next time it won't start, check for spark.

 

I would agree, check for spark & fuel when it won't start. Not even attempting to start with a shot of starter fluid implies an ignition problem.

Don't know what to say on the small holes you're seeing in the ignition module but my suspicion is that they're unrelated to anything.