My 86 ford f250 has the efi 302 and is running rough when in gear and backfires a little. Any ideas why? And could it be something besides timing? Ive retimed it, fuel pressure check, checked the sparkplugs, replaced the fuel pressure regulator and fuel filters and spark plugs wires and coil are just a month old

 

Rough in gear i meaning puahing the throttle when its in drive

 

First thing to do when diagnosing a computer-controlled engine is ask the computer what it thinks is going on; here's how:

Ford Fuel Injection » How To Run a Self-Test

 

Have you done a compression check?

I've been having similar issues with my '87 f250 302. It runs fine until the engine warms up, then it has an awful misfire, causing it to run really rough under any kind of a load (as soon as it's in gear and you give it gas). I finally gave up chasing possible culprits: egr components, tps, aic, vacuum leak, etc. I broke down and took it to a real mechanic who did a compression check and found #1 down around 120, with the rest in the 180's. Further inspection revealed the burnt valve on cylinder #1.

Hope this helps.
-j

 

Ive done a compression test and a fuel rail pressure test and they check out fine

 

Finally figured it out. I had a capacitor on my sound system which backfed into the battery casuing a voltage spike which fried my EEC