hi rpm miss

[mars23z]

I was wondering if anyone has had this problem and what to do. My car runs great except when I m in 3rd or 4th and get on it I have a miss or a hesitation. Its only when the rpms get up around 5000-5500. I think it might need the carbs tuned or perhaps a distributer. Where should I start to look? Thanks for the help. Chris

[DaveN]

Guessing you still have the stock ignition system.... it's probably a simple ignition problem, just an indication the car is due for a tune up.

Try new plugs (one heat range colder if the old ones have deposits melted onto the insulators) & make sure the dwell is right.

If that doesn't fix it the next suspects are the distributor cap (arcing from one contact to it's neighbor) and the plug wires (insulation breakdown).

[albert_ey]

A similar was happening to me, The Fuel tank needed to be refinished, it was really dirty inside. I have also had that problem recently, It turns out my car needed higher octane gasoline. Give it a shot see if the higher octane works for you.

[1973Z]

When I had a miss it turned out to be a spark plug.

[JimmyZ]

I'd think distributor bushings first. Take the cap off and see how much play there is in the shaft. I had a distributor which behaved the same way. When I took the cap off I was amazed to find that the rotor was turning so sloppily it machined the inside of the distributor cap!

As mentioned above check the plug wires. Make sure that they are not laying on anything metal and that they are in their plastic stand-off clips.

Fuel problems sometimes sound like ignition problems. As mentioned above a dirty tank/clogged fuel filter can sound like a miss. Happened to me years ago.

Hope this helps

Jim

Sometimes fuel issues sound like ignition

[mars23z]

The plugs are brand new. I recently swapped out my L26 for an L28. When I had the L26 this happened until I replaced the pugs then it seemed to go away. Now when the mechanic swapped engines he used my pug wires from the L26 because they were fairly new and used brand new plugs. Is the plug wire the same for both engines? I will try the distruibuter this week. Iam sure the dist could stand to be replaced. What is a good upgrade for dist, ignition etc.Thanks Chris

[2Forty]

If you have a points style ignition the points may be bouncing. Try a new set.