I wasn't exactly sure which forum to put this in, but here is the problem:

I have an 86 E150 5.0L v8 conversion van. It had been sitting in my garage for 3 years before just a few weeks ago when I decided to get it up and running again.

I put in new transmission fluid, changed the oil/filter and air filter. For the most part it will start up quickly and run very smoothly.

What happens is that maybe 1 in 4 times it will not turn over when I turn the key. I'll have to wait 3 or 4 minutes and then, crank the key in the ignition while applying much force as far as the key will go to get it to turn over. It usually starts with no problem once it turns over. Could this be a sign that I need a new ignition switch?

The other problem is that occasionally when I am downshifting to make a turn - specifically, a right-hand turn - the engine will die. If I slow down almost to a stop before making the turn, the engine will stay running. Any amount of excess speed causes it to die (occasionally). I have Not checked the engine timing yet.

Lastly, I noticed while on the freeway that if I drove at a speed of 45 or above while the road curved to the right, the engine would sputter a bit occasionally. Once the road straightened out, the engine ran smoothly again.

I'm planning on ordering and installing a new fuel filter. The vehicle has a canister filter and also an in-line filter. Which ought I to replace, if not both?

Thank you for your help!

 

Replace both filters if you have them. The canister filter is a Pre-Filter as you van most likely has two fuel pumps. You have a LOW PRESSURE pump in the tank and a HIGH PRESSURE pump on the frame rail. It's a dual circulating system. The LOW pressure pump feeds the HIGH pressure pump. It's possible that your LOW pressure pump may be failing. Also check to ensure that the grounds and ground connectors coming off the battery are solid connections. Ford used a fuse connector on the small ground lead off the battery post in the 80's that would sometimes fail. This occured on my 88 Ranger making a right turn. Finally let loose on a right turn and engine died solid. Drove me nuts for about 3 days. I cut the fuse out and make a solid crimp connection. They used the fuse connector for assembly line install ease.

Suspect yopur ignition switch is worn and failing for that issue.

Being an 86, I would also replace the rear gear lube with a good synthetic lube and repack the front wheel bearings.