Chug - Chug - Chug.....

[TedW]

A while back I posted that my truck was hesitating in third / under load. It turns out to have been stale / old gas: some octane boost and other miracle additives took care of it.

Now I have another issue: When I start the truck cold it chugs violently (and usually stalls) until I push the choke back in. Very, very rough starting, but once it's idling everything is smooth as silk.

I never had this problem before. Some details:

Weber 1 bbl.
Pertronix
New head
4k on engine

Any ideas? Thanks in advance for any / all replies,

Ted

[stomper]

It's either fuel or electrical. I recently had a similar problem, which was fixed by cleaning the carbon off the rotor button contacts. May be this, points carboned up or not gapped correctly, or perhaps the fuel filter is clogged or there is crud in the fuel bowl. Start check g a few things.

[TedW]

Stomper:

I have a Pertronix and a new Ducellier - everything has run great until recently.

I also have a Carter 4070 electric fuel pump - again, eveything's been great until recently

Ted.

[printjunky]

Sounds likely fuel/air (vacuum) related. I'd double check fuel flow (pressure/volume - I'd just unhook the line and do a visual flow test into a jar or the top of carb). The 4070 is supposed to be great, but I'd still suspect fuel delivery. Might not be the pump, might be a clog, filter, kink, etc. And I'd do a "spray-test" for vacuum leaks (and/or a visual/touching/listening check for obvious ones)

Also, I think the Webers have a clogging issue due to a poorly placed orifice, but I'm not sure. I had a Weber on a SIII in college, but have a Rochester I swear by now.

But I'd also check the ignition system over well. I had some spark plug wire arcing recently and while my problem was primarily fuel-delivery related, I'm sure that (and a vacuum leak) didn't help.