Seeing as the weather is finally getting nice here in PA I decided to take my 78 F150 (429cj) out for a cruise. During the winter I would start it up and let it run, sometimes take it out, every week or two just to keep parts moving and never encountered this issue.

Yesterday when I took it out to run some errands (20 mile round trip) the engine started jumping a bit as though it was choking out; was about 15 miles into the trip at this point. At higher rpms this would cease, but as soon as it went to lower rpms would start up again.

Slowing down at a red light it stalled out and wouldn't immediately start. I sat there for about 5 minutes, got it running again (lots of black smoke out of the exhaust on start) and made it about a mile before it did it again at the next light as I slowed down to about 5-10 mph. Waited 5 minutes, started it up w/ black smoke again, and drove it all the way home running higher rpms and cruising through stop signs to avoid another stall. Finally got it into the driveway, stalling as I pulled in.

I let it sit for a couple hours, went out to start it, same black smoke, it picked up it's high idle as it does when it starts, gave the engine a slight rev to drop the idle, and listened as it attempted to try and stall. I'd rev the engine slightly to try and stop it, but would see the light black smoke again, eventually I gave up and it stalled out.

Only thing I did recently was filled up the tanks; was told to run premium in it when I bought it, so I'm not sure if it's something to do with bad fuel/carb/etc.

Any help/ideas would be greatly appreciated.

- Carter

 

Almost sounds like the choke isn't opening completlely, is this a manual or electric choke?

 

I know tons about computers/networks and almost next to nothing about mechanics, so bear with me here as I'm trying to learn more about my rig.

From what I just read online it sounds like I have an electric choke... I just pump the gas 4 times, fire it up, it idles high for a bit, I give it a slight pump of the gas and idle drops to normal. No manual intervention required other than the gas pedal required.

Your question made me think of something, I've gotten zapped a few times when opening the door (more than a static shock)... possible I have a short that could be screwing with the choke?

 

You got some trash in the needle/seat and it's flooding.
What carb you got?
Could be rebuild the carb time!

 

One time will suffice, just to set the choke, anymore just floods the engine.

 

Got it warmed up (one pump start, Thank you montana_highboy) and took off the air cleaner cover and carb was wide open, which is how it should be from what I read.

After it bogged/stalled out I did notice a small amount of smoke coming out from the one side of the carb, assuming this is residual evaporation? Should I try spraying some carb cleaner in there or ?

Thanks again.

 

THat's not residual evaporation.
That's flooding!!

 

Thank you sir.

Got some time and checked it out... flooding in the front right barrel and also a small leak coming from the throttle lever area.

 

Take a pic of your carb.
THen we can help you fix it.
There's several tricks to try before you rebuild your carb to cure the flooding.

 

Just wanted to follow-up and close this post. Finally had some time to work on the truck and found the issue was fuel pump.

Fired it up, it stalled out after about a minute, and noticed a black puddle under the engine (as well as all over it). While my knowledge of mechanical parts is very weak, I called my buddy who's a mechanic and explained what happened and where oil looks like it came from. Had him come over, fired it up, and he confirmed part/issue. Switched it out and back to cruising again

I do appreciate all input/ideas and thank you all much.

-Carter