Yellow truck - 79 F350 460 C6 4x2

Having three trucks means that they don’t get driven everyday. One of the problems with this is that the “new” gas boils out of the carb and fuel lines-a problem exacerbated by the Yuma heat, which has been topping 120 lately.

So years back, I put electric fuel pumps in all the trucks. I get in, turn the key, wait a moment for the pump to change tone, then fire it up. Works great...until it doesn't.

Last weekend, I was picking up the daughter from work at about 3 pm. 118+. I had to wait a few minutes for her, idling with the AC on, then we took off. About a mile down the road, the truck died under acceleration-but only for an instant, then came back to life. All the gauges looked good, except the air/fuel ratio, which was momentarily very lean. After that moment, it was fine. The rest of the trip was uneventful

The next day, I was running errands, and the truck was fine. Went to pick up the daughter, and the exact same thing happened again. Driving along, momentary hesitation, then all was well. Getting weird now...

I wasn’t sure what was going on, but since it happened a moment after sitting in the heat, I figured it was some kind of vapor lock.

The next morning, under cooler and overcast skies, I drove past the daughters workplace and got into the left turn lane, rolling toward the intersection. That’s when I noticed I had no power assist on the brakes-the engine had died! Since I missed the arrow, I had a cycle to get it started, and it did start, for just a moment. Additional cranking only lowered the battery

The guy behind me happened to be a coworker, and we pushed the truck through the intersection and got it into a parking lot. I called AAA, and the tow truck eventually showed up. I explained the situation, and the driver jumped in, fired the truck up, and drove it onto the flatbed. Maddening!

Thinking it was starving for fuel, possibly doe to the external fuel pump overheating, I ordered a replacement pump and waited for the weekend.

Saturday morning finally arrived, so I went out and fired up the truck. It started right up, and I moved it to a shady spot to work on it...

Replaced the fuel pump. Truck fired right up! As I was cleaning up the tools, the truck died

Swapped-in the ignition module from the 78. Truck fired right up! As I was cleaning up the tools, the truck died

Swapped-in the coil from the 78. Truck fired right up! As I was cleaning up the tools, the truck died

Replaced the pickup coil in the distributor with the spare I keep in the toolbox. Truck fired right up. And stayed running

Ran errands today with no problems. Ordered another pickup coil for the toolbox...


Cracks in the pickup

 

Glad you got it figured out! Hunting down an issue like that is enough to drive you crazy.

 

Thanks-it was a long day!

Anyway, I had a bad pickup coil in the 77 a couple years back, otherwise I’d never have considered the distributor

 

My pick up coil has a crack between the two studs on the metal part. Truck runs good ,but wanted to replace it. Two pick coils from Napa didn't work ,starts but sounds like it's running on 4 cyls . I just put the cracked one back in and it's been running fine. I did buy a Standard part for it and it is sitting on the shelf(ohms out good). 79 f250 460 One of these days I will install it and see what happens. I guess I should put it in side box just in case. Either that or just get off my oss and install it.

 

It's nice having two parts-cannons with reusable cannon *****! Borrowing parts from another vehicle for diagnostic purposes is cool. Buying new parts for that purpose is not.

 

Living where it gets to 118 degrees is a little crazy, I don't know that I could take it. But then, I'm sure living where it gets down to -10 (or colder) in winter doesn't sound too sane to you.......

I start troubleshooting with the pickup coil first, after a few times of replacing it last. It always seems to be my problem.