Intermittent stumble and miss
Intermittent stumble and miss
1962 98 394ci
Car had a stumble with an occasional pop through the carb at the 2nd gear shift and a steady miss while accelerating.
Every now and then it would fall on its face at the shift then pick back up but slowly.
Replaced plugs, wires, coil, rebuilt fuel pump, new alternator to replace generator and external volt Regulator.
Timing set at 6- 6.5 btdc. Hook vacuum advance up and it maxes out around 44*. No detonation.
Dropped gas tank, cleaned pickup sock and added new fuel.
New rubber fuel lines and filter.
Ran great.
Developed a bit of a hesitation after a few drives but nowhere near as bad as it was.
Adjusted choke and a few other carb pieces today and she ran like a scalded dog on the test drive. Better than ever.
Parked her in the garage. Took it for a spin a while ago and now she runs like she did before all that work.
I'm leaning toward a bad ground/ loose wire some where but where?
New connectors on coil wires and alternator wires.
Any ideas?
Thanks
Car had a stumble with an occasional pop through the carb at the 2nd gear shift and a steady miss while accelerating.
Every now and then it would fall on its face at the shift then pick back up but slowly.
Replaced plugs, wires, coil, rebuilt fuel pump, new alternator to replace generator and external volt Regulator.
Timing set at 6- 6.5 btdc. Hook vacuum advance up and it maxes out around 44*. No detonation.
Dropped gas tank, cleaned pickup sock and added new fuel.
New rubber fuel lines and filter.
Ran great.
Developed a bit of a hesitation after a few drives but nowhere near as bad as it was.
Adjusted choke and a few other carb pieces today and she ran like a scalded dog on the test drive. Better than ever.
Parked her in the garage. Took it for a spin a while ago and now she runs like she did before all that work.
I'm leaning toward a bad ground/ loose wire some where but where?
New connectors on coil wires and alternator wires.
Any ideas?
Thanks
Last edited by Mikeyt; Sep 1, 2024 at 05:24 PM.
Make sure the distributor mechanical advance weights move freely. Not unheard of for the distributor lead or the advance plate ground wire to get a bad connection either.
That steep ratio drop between 1st and 2d shift makes a lot of problems.
That steep ratio drop between 1st and 2d shift makes a lot of problems.
We checked the weights and they seemed to be fine. No hang ups. I will give them a thorough once over again.
One thing I did notice is the the timing mark jumps all over when accelerating. Once it gets over a certain RPM, I'll have to pay more attention to the exact number next time, it stays put. Not sure if that's normal.
It did that when the initial settings were changed and it ran fine. Until it didnt.
There is a wire that attaches to the bottom of the distributor body and the negative side of the coil. It is tight but not sure of connection underneath. Is it corroded or not? I'll have to get a mirror in there.
I will also check connections under the cap.
Thanks for the reply.
I know this may not be an easy one.
Man I thought I had this thing dialed in for a minute.
One thing I did notice is the the timing mark jumps all over when accelerating. Once it gets over a certain RPM, I'll have to pay more attention to the exact number next time, it stays put. Not sure if that's normal.
It did that when the initial settings were changed and it ran fine. Until it didnt.
There is a wire that attaches to the bottom of the distributor body and the negative side of the coil. It is tight but not sure of connection underneath. Is it corroded or not? I'll have to get a mirror in there.
I will also check connections under the cap.
Thanks for the reply.
I know this may not be an easy one.
Man I thought I had this thing dialed in for a minute.
I forgot to add there is also a random loud ticking noise from the top of motor occasionally. Sounds like a stuck lifter or something. Usually clears up after a few minutes. There is no rhyme or reason why it does it when it does. Totally random.
It was not making that noise when running poorly yesterday but it did it earlier in the day for less than a minute.
It was not making that noise when running poorly yesterday but it did it earlier in the day for less than a minute.
Pulled cap and rotor.
Primary wire and condenser wire go behind a screw on the contact point base.
They weren't loose enough to wiggle but I was able to easily pull them off without loosening screw.
All other wires and connections looked good.
Points had some white build up on negative/ stationary side.
Cleaned points, reinstalled. Cleaned and Tightened connections, set dwell and timing and she runs great again.
We shall see. I hope it's just that simple.
Primary wire and condenser wire go behind a screw on the contact point base.
They weren't loose enough to wiggle but I was able to easily pull them off without loosening screw.
All other wires and connections looked good.
Points had some white build up on negative/ stationary side.
Cleaned points, reinstalled. Cleaned and Tightened connections, set dwell and timing and she runs great again.
We shall see. I hope it's just that simple.
Thread
Thread Starter
Forum
Replies
Last Post



