Good morning,

I’m having an issue at highway speeds on long trips when changing altitude where the revs with randomly drop to 0 and bounce back up almost instantly, the car stutters and feels like it’s going to stall when this happens. It’s usually just as it drops under 2.5K revs under load, almost always on inclines and almost always on long trips, although I have experienced this once or twice around town.

Thinks I’ve gone through so far
- Replace all vacuum lines on carby
- replace air filter and pcv
- clean carby and replace gaskets
- reset idle speed and mixture
- check spark plugs (they were still clean)
- check timing (correct to Haynes manual)
- check and set automatic choke (tried setting it all the way to lean too)
- changed distributor points

I’m not sure what it could be, I’ve read a couple similar issues but haven’t had any luck yet. It happens very occasionally, but always on a 4+hr drive and very rarely around town. It never happens sitting over 3K rpm.


Many thanks for any advice.

Cheers,
Mitch