Project Z

Hey guys,

I can't figure this out. Car's got vac-advance distributor (not computer controled) and an old carb.

When idling in garage in neutral (manual trans) the car will rev just fine, no hesitation or stumble. Put the car in any gear and when comming off idle, just tipping in or nailing the gas, it goes into a pretty good stumble for a second and then the power comes back on.

I've played with the timing several times going from slightly retarded, straight up, advanced all with the same stumble. The distributor is quite old but it seems to be advancing normally as the throttle is applied under a timing light.

I'm at a loss for what to try next. Thanks for any help/advise.

Keegan

RB83L69

It's a fuel issue.

What carb is it?

Project Z

Here's where you'll get mad at me. I am restoring a 1987 Iroc. I'm also doing a 1965 Mustang convertable. (I know, sacreligious). The problem's with the 'stang. It's got the factory 2bbl set-up, which I've got the rebuild kit for, just havn't done it yet.

I understand if you want to lobby to have me kicked off of the forum, but this is the best one one the net and I havn't found a decent Ford one yet. Sorry.

Keeg

RB83L69

The old FoMoCo annular-discharge 2-barrel??

AAAAH-ha-ha-ha-ha-ha-ha-ha-ha!!!!

The cure is a Holley 4412.

You're right, this topic will probably get closed soonly.

Project Z

That's what I was affraid of, thanks. I think I'll check Jegs ect.. for the best price.

You sound like you speak from experience, so no use tring to re-hab the factory carb?

Thanks again.

RB83L69

No actually, I've never seen or heard of anything remotely like that. There's a first time for everything.

Most likely, the fordium (an isotope of the same element as chinesium) has dissolved somewhere. That's what seems to happen to those.

It sounds kind of like the accel pump isn't working; but I'll bet that if you CAREFULLY look down into the venturis and open the throttles slowly and watch the fuel feed out of the discharge "nozzles", you'll see it come out in spurts and blobs instead of a smooth flow. I've seen a number of them do that, and the only cure I ever found was another carb. And it sure as hell wasn't going to be one of those FoMoCo POSs if it was my money, or if I could talk the customer into getting something decent.

I've run alot of 4412s over the years.... had one for a few years on a 59 Ponitac I used to have, with a 389. Ran a whole lot better than the old Rochester 2G that came on it.

A 7448 is another one that would work. It's 350 CFM but otherwise very similar to the 4412. I have the marine version of that on my boat (F*rd 302), it runs surprisingly hard.

The ones of those that used to make me laugh the hardest were the ones where F*rd used that stupid EGR spacer plate, which would erode so bad that you'd not only have a major exhaust leak into the intake, but also to the outside world, at the base of the carb. My little brother and I used to keep one of those in stock, we replaced them so often.