I have a 1986 F150 302 that I bought about a year ago. Once it got to operating temperature it would struggle idling or accelerating after turning the engine off and then starting again. I could usually limp it along and get it where I needed to go. I watched several youtube videos and read many forums and ended up throwing a parts bomb at it. I replaced: Idle control valve, throttle positioning sensor, Map sensor, egr valve, ignition

control sensor, coolant temp sensor, distributor cap, wires, plugs. Over winter and spring it is not as bad but now in Summer post 94/96 degrees after repeated starts and stops ( engine off truck sitting) it has a really rough start and dies. I have tried to gun it and rev it with no relief. I can let the vehicle sit for about 30 mins (same heat of the day) and it is fine and experiences no issues while running. It does not appear to be overheating but I did notice the temp is of course much higher when sitting than when the truck is moving and the fan is running.


the previous owner did a smog pump delete but left everything else on. I went ahead and did the EGR delete and plug the circuit with a closed sensor and it has stopped it from having issues when hot and running. Only now after turning the vehicle off after many drives on very hot days. I have felt the rail side fuel pump and it and the lines are cool to the touch and i have checked some of the vacuum lines are they have vacuum.


All the videos I watch and forums I read never seem to post the solution. Thanks for reading and I sure hope someone can help. I love this truck

 

What does the inside of the dizzy cap look like, is there a brownish dust in there ? What do the terminals look like on the coil ? Are they corroded ? Mine were.


But not anymore.

 

I also replaced my radiator a few years back too, I can't remember why, it must have begun to leak...

 

Pull the codes and see what you have.

 

Besides codes get a fuel psi reading with regulator working and not and vacuum at idle, 2000, 3000 rpm
Dave----

 

Let me look

 

I have checked the radiator and it does not seem clogged inside or the fins. I was thinking about changing the radiator cap and the thermostat to see if that helped.

 

Thanks, I will look today

 

This is what one of the members here told me to get years ago, to clean up the corrosion on the terminals.

 

You can not tell if the radiator is good inside or not by looking at it only from a flow test.
Now you can start the motor, radiator cap off, and when you get flow and the lower hose gets warm but not really hot.

Shut motor off and start feeling across the radiator core. If it flows some what good the full core should feel the same temp across it.
If you feel any cool spots that area has no flow and needs to be rodded, good luck finding a shop, or replaced.
Dave ----

 

Why are we worried about the radiator if the truck is not overheating?

 

^ agree. It sounds like some electrical component in the ignition system is getting hot ? could it be that thing attached to the distributor ? Isn't that the ignition control module ?

 

Here's a link to reading the CEL codes.

https://www.google.com/search?q=how+...t=gws-wiz-serp

I also wonder if the OP has the shroud on the radiator ?

 

I have replace the ICM. I have not replaced the coil but when I start it, the times it has issues it seems like a fuel starvation not electric

 

If you think fuel issue, you need to get a fuel pressure gauge and watch that while cranking and running.

Have you verified the coil connections are clean ?

I think we have talked about making sure the fuel pressure regulator is in good shape ?