Hello All,

I've got a problem with my engine in my '65 F100 CC. It has a 1970 351 in it. Here's the problem, yesterday it seemed to have a delay when I hit the throttle so I decided to advance the timing a bit to see if I could get it to go away. Needless to say when I drove it home, about 30 miles, that it was running really rough and sounded like it was missing on a couple of cylinders. when I got home I moved the distributor back to where it was originally ( i had marked it's placement beforehand). When I cranked it up this morning everything seemed fine, accelleration was fine so I drove it to work this morning (around 30 miles). When I got off of the interstate, the same thing happened. The engine sounded as if it were running without a couple of cylinders. I still had a few miles to get to work and just as I drove into the parking lot it seemed to clear up a bit. The ignition is the pertronix with an accel super stock coil. The carb is a month old Holly 600CFM which has been running fine. I don't know the age of the plugs but I intend on checking them next and possibly the plug wires. I will also replace the rotor and cap as they appear to have been scorched a bit on the tips. It doesn't appear to be smoking at all, just running rough. Please Help!!! I want to get this fixed before my wife lays into me about my addiction to old vehicles. yadi,yadi, yadi...

Thanks,

JamesH

 

Intermittent ignition problem! I hate those! Check the mechanical and vacuum advance on the distributor, check the shaft for slop. Try a new coil, try another Ignitor. The Pertronix rarely fails but you may have one. You do have 12 volts to the pertronix when the engine is in run mode right?
William in Atlanta

 

When you say a delay, do you mean when you hit the throttle from idle? If so, you may have two problems. The plugs are fouled and/or the accelerator pump is not functioning properly.
The acc.pump is used to give a small squirt of fuel due to the atmospheric pressure change when the throttle blades just start to open. The pump provides extra fuel during this quick "lean" period.
But thats just one possibility. Check that distributor anyway.

 

Well, believe it or not it appears to have all been caused from the vacuum line to the power booster. Which at highway speed didn't show as many problems but at idle, it was horrible. In the process of accidentally noticing the vacuum line I did re-adjust the pertronix gap (it was also off), replaced the cap, button, and all of the plugs (in that process I found out that the previous owner had all of the plugs gapped at .45 instead of the recommended .35). I also found number 8 cyl. had no gap whatsoever and the had fouled pretty bad. Needless to say, the truck is running great now with a little more power since it's hitting all 8 and the delay is also gone. (Probably more related to the ignition)

Thanks for all the help.

JamesH

 

Glad to hear you found the problem. It's always nice to hear the results of a problem when the solution has been found.