Yo..new guy here. I recently bought a beautiful low mileage 87 F-250 with some nice mods, and I've been doing more upgrades since. So here's the skinny...got it with a very slight stumble...assumed to be a carb stumble, worse when cold and barely evident when warmed up...figured it needed a rejet or maybe a carb gasket. I don't know how to tune/diagnose/rebuild carbs so I took it to "a guy" who told me to give her a tune-up first, before he would look at it. I did the tune-up this past weekend...cap/rotor, plugs, wires, oil/filter..air filter was just done prior. Threw new valve cover gaskets on at the same time cause the old wires were oil soaked on one side. Soooo. I drove it Mon and Tue and I could feel a cleaner fire...just a bit, ran great. This morning (Wed) it was cold, way cold...35F The stumble has been obviously worse when cold the whole time I've had her. This morning I had a MFer of a time starting it because it wouldn't idle properly (no auto choke normally). I assume it was lack of auto choke/cold temps and wasn't worried. Once started it seemed to idle a bit rough..barely noticeable. Then I took off...good for about 50 yds then began to stumble. It stumbled/stalled at idle all the way to work...20+ miles. I though it would warm up and be fine any minute the whole time...never did. It stalled at every light, cause I was to sleepy to realize I could rev it to keep it alive. I got to work and it stalled as I slowed to put it in park. It ran fine at high rpms on the way. So I figured it would be fine after work (warmed up to 65 today), since I've always assumed it was the carb gasket that caused the stumbling, and I had figured it was really shrunk in the cold this morning. It started fine, but wouldn't run at idle just like before. I popped the hood to look for something/anything...nothing. I installed an MSD cap with that goofy extra thing that goes on top to harness wires or whatever. I threw it on cause it looks hot, but noticed the coil wire that sits in that clip thing only goes down so far and doesn't feel like it connects fully...anyway, after driving with it like that for 2 days with zero issues I wasn't concerned. When it wouldn't idle after work I took that top thing off so I could make sure all cap connections were gravy. I was able to push the cap and one other connection down a bit. I fired her up...runs fine..problem solved...yeah right. I drive all the way back to town to pick up my son with no issues. I got a block away from where I picked him up and it started again, but worse (I could still feel a VERY slight hesitation at higher RPM/after initial takeoff). I pulled over, checked the rotor and all cap connections, plugs, vac lines..everything I could look at...nothing. I limped the MFer home, reving at lights to keep from stalling, etc. So, it is a stumbly/misfiry feeling. No backfire, but feels close. Almost forgot..as I was parking at my house it stalled as I was putting it in reverse since it wouldn't idle. When I restarted, backed up 20 ft and put it in park it idled fine...of course it did, right. Being that I don't know **** I think it might be the timing chain, or maybe the distributor. Sorry for the novel...just wanted to paint the full picture. PLEASE HELP!!!!


Here's a pic of her

 

This should help. Skip adding it to the oil if not planning on changing oil in the near future.

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