I did a fair amount of searching through this forum and couldn't find anything that sounded exactly like the problem I am having. My stock '79 stutters/stumbles when I'm cruising at 55 - 60 mph. If I kick it down, it'll go ok without stuttering (although it seems to be down in power). It used to stall out at stop signs, but since overhauling the carb that doesn't seem to be a problem anymore, although it did stall on me once since then. I replaced the fuel filter last fall and that didn't help.

Could this be an ignition problem? I've always heard that the distributors on the early cars were bad. Mine is stock...could it be the problem? How can I test it?

Could it be a fuel pump problem? I did the carb job myself, so there is no guarantee that it was done correctly, although it seems to be running the same as it did before I put the carb kit in.

Thanks for any suggestions.

 

Vaccum leak? Could be ignition, have you gone with the later model distributor? How does it act at WOT? if it will accellerate fine through all gears, it's prob not a fuel flow problem. How well does it idle?

 

What he said....

 

No, the distributor is the original. It accelerates ok (no stuttering), but it seems to be down on power versus when it was younger. I don't drive this car much anymore so it's difficult to make good comparisons. One thing I forgot to mention...the tach jumps around alot. This has happened for many years but has gradually gotten worse and worse. It seems to idle ok.

 

I'd upgrade the ignition then, plenty of info out there on that, just go with the later model distributor.

 

Tach jumping means part of your trailing ignition is messed up. Should just need a basic tune-up. Cap and Rotor, plug wires, spark plugs, test the ignitors and coils.

 

If it's a stock 79' it doesn't have ignitors being its a points system.

 

That's correct...it has points. It's been a while since I did a tune-up, but it only has a few hundred miles on it since. The tach was jumping before and after the tune-up. I've always heard that the original distributor on the early cars was prone to early failure, and have always assumed that was the cause of the jumping tach. Are there any physical signs that the distributor is bad?

 

IIRC, 79 - 80 cars have tach signal off the leading ignition. Otherwise, coldy's right. If the tach is bouncing, look at the ignition system. Something's not right.

 

Thanks for the suggestions. I have a distributor off a later year...no idea if it's any good. I've been trying to keep this car original (I bought it new in May of 1978), but hopefully I can make this conversion in a way that it can be un-done if I want to. Is there a way to test the current distributor to see if it's bad or not? As previously stated, I've always heard that the early distributors were not very good and would fail early on...but what does that mean? What goes bad? Is there a way to fix it if it's bad?

Thanks

 

Hey everyone - I think I found the cause of the stuttering when cruising. I decided to check out the coils (I had never had the coils out before) and the center connector on the leading coil was almost completely corroded away...I'm surprised it ran at all! That doesn't explain the jumping tach, but it should solve the rough running problem.

Thanks again for all your help.

 

i've had a similar problem.

when taking off rather quickly it does fine up until about 80 when it just starts stuttering and jerking. I've got a 12a with 80,000 miles on it. weber 45dcoe, holley red fuel pump, RB header and presilincer, holley pressure reg. Any ideas?

oh yea, new fuel filter as well.