C2 Acceleration Problem

[Sean L.]

9 months ago I bought a 1964, 365SHP roadster. The block is original with a after market Edelbrock carburetor. Unfortunately I know very little details concerning the level or quality of the power train restoration completed circa 2002. When I bought the car it ran great, with lots of low end torque, smooth idle and acceleration. However, shortly after I installed new AC 45R plugs (attempting to minimize some drive train lash) acceleration and general engine "smoothness" quickly deteriorated. The car now sounds and feels like a poorly tuned Harley Davison under any type of load above idle. I pulled the new plugs and noticed that one was fouled. I then ran a compression check and all cylinders held 150 PSI +/- 5 PSI. After that I decided to eliminate the spark plug variable, so I replaced the plugs again, but this time with new wires, but to no avail.

I'm not sure where to go from here. The 64' CSM talks vaguely about vacuum or carburetors problems, but I think I would be reaching in the dark at this point.

Any help/advice would be appreciated.

Thanks,
Sean

[Timothy B.]

Re: C2 Acceleration Problem

Sean,

Are you sure the spark plug wires are installed in the correct firing order? Outside of ignition points and distributor cap, it may be time to take the car to a good mechanic because you can spend $$$ on parts that are not bad.

[Joe C.]

Re: C2 Acceleration Problem

"When I bought the car it ran great, with lots of low end torque, smooth idle and...."

You do not have the original, or reproduction of your original "30-30" camshaft installed in your engine. Idle vacuum should be between 9 and 10 in-hg @ about 800RPM idle.

Now to your problem:
As stated above, check the ifring order of your newly installed wires. Also check for a broken plug insulator. If the problem was not present before you disturbed the plugs/wires/distributor cap, then it was caused by one of those items.
Reinstall your old plugs and see what happens. Same for your old wires.......a stretch, but you may have a bad wire. Eliminate everything that you disturbed, FIRST. Then get back and we'll go from there.

[Salvatore I.]

Re: C2 Acceleration Problem

Had a similar problem; after everything that was obvious was replaced (plugs; wires) I opened up the distributor cap and found that the metal tab at the top of the rotor was loose(it wobbled) and made poor contact with the distributor cap....Masked a firing issue.....

I would check this now that you have taken the other steps....With good compression in every cylinder, something is not enabling one or 2 plugs to fire....check the underside of the distributor cap for a broken contact or better, see if the rotor is intact....just my 2 cents worth.

[Sean L.]

Re: C2 Acceleration Problem

Tim, Joe and Sal,

Thanks for the help on this. I'll start with the plugs and work backwards to the distributor cap. Sounds simple enough. I'll let you know what I find.

Thanks again
Sean