C2 Misses at high RPM

[Wes W.]

Need some help. My 1965 with 365hp misses at high rpm (>4000) in 2nd gear. I don't notice it doing it in 1st, 3rd, or 4th. Car has electronic points. Local mechanic was thinking the vaccum advance may be bad. Car runs strong otherwise and starts right up.

Any other thoughts?? Thanks in advance for your advice!

[John H.]

Re: C2 Misses at high RPM

Need some help. My 1965 with 365hp misses at high rpm (>4000) in 2nd gear. I don't notice it doing it in 1st, 3rd, or 4th. Car has electronic points. Local mechanic was thinking the vaccum advance may be bad. Car runs strong otherwise and starts right up.

Any other thoughts?? Thanks in advance for your advice!

Is this at wide-open throttle? What do the plugs look like and what type/heat range are you using? How old are the rotor, cap, and plug wires?

The vacuum advance is inoperative under load.

[Loren L.]

Re: C2 Misses at high RPM

If it has original pop-up pistons, I'd suspect fouled spark plugs - even with electronic ignition the OEM plug wires are inadequate.

[Wes W.]

Re: C2 Misses at high RPM

Thanks for the replies..I will check the plugs and wires. As John H. indicates, its when the throttle is wide open and almost always at just over 4000rpm.

Any other suggestions or thoughts..throw them at me!

[Dan H.]

Re: C2 Misses at high RPM

Check dwell run out on the distributor, see if it goes way off when you increase RPMS. Happy hunting. OOPS, just saw it had electronic pts.

[Joe R.]

Re: C2 Misses at high RPM

Yeah, I'll throw one at you. When was the last time you changed your valve springs?


JR

[William C.]

Re: C2 Misses at high RPM

What plug gap? What wires?

[Jeff B.]

Re: C2 Misses at high RPM

Wes, I know you said high RPM but is the problem that you see at at hi revs when its under a load (hard acceleration), or no load like a sustained 4000 RPM cruise, or both. These conditions are different when considering fuel and air delivery and ignition timing. Often with electrial (spark) problems the miss is actually present all the time but can only be noticed under certain conditions. Start by simply checking or replacing the plug wires and plugs.

[Michael H.]

Re: C2 Misses at high RPM

Local mechanic was thinking the vaccum advance may be bad. !

Wes,

You might think about looking for a different mechanic.

I agree with others here. I would look at spark plugs and wires first.