Posted August 4, 200717 yr comment_217445 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 Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/ Share on other sites More sharing options...
August 5, 200717 yr comment_217479 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). Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217479 Share on other sites More sharing options...
August 5, 200717 yr comment_217498 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. Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217498 Share on other sites More sharing options...
August 5, 200717 yr comment_217504 When I had a miss it turned out to be a spark plug. Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217504 Share on other sites More sharing options...
August 5, 200717 yr comment_217506 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 helpsJimSometimes fuel issues sound like ignition Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217506 Share on other sites More sharing options...
August 6, 200717 yr Author comment_217549 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 Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217549 Share on other sites More sharing options...
August 8, 200717 yr comment_217765 If you have a points style ignition the points may be bouncing. Try a new set. Link to comment https://www.classiczcars.com/forums/topic/25105-hi-rpm-miss/#findComment-217765 Share on other sites More sharing options...
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