[Steve B]

Just put an Autolite 2100 on my '56-F100. The original carb was the old 3 bolt base Ford carb. That old carb leaked, iced in winter, and was hard to start hot. I changed to the later manifold, and put on the new 2 barrel purchased from Pony Carbs.

The engine will idle well down to 500 rpm, has good vacuum and runs well overall, but does two strange things:

When BACKING slowly (very light throttle-1,000 RPM or less) up a steep grade which is sometimes necessary where I live and work, the engine will run fine for about 10 seconds then die out as if starved for fuel. I can re-start easy enough. I thought a low fuel level was the problem until I realized the motor runs great up grades at WOT-so plenty of fuel right? Could this be a low vacuum signal not pulling fuel through the emulsion tubes?

The other weird thing it will do is when the engine is fully warmed up, and has sat for 10 munutes or so, the engine will start instantly with no throttle, run for about 2 seconds, then die. The engine will then re-start instantly with no throttle and keep running.

I am also getting a slight surging at mid RPM's light throttle.

Timing is around 12 BTDC, manifold vacuum to the dist gives 8 deg. more. Total timing is about 36 degrees at 3,000 rpm.
Any Ideas?
Steve B

[ August 29, 2002: Message edited by: Steve B ]</p>

[dmorris1200]

Just thinking out loud here, haven't experienced same problems. Could float level be off, while backing up steep grade would shift gas toward front of fuel bowl while accelleration tends to push gas toward rear of bowl. Maybe a real long shot but old factory carbs used to use one-way check valves in the fuel filters to aid in start-up.

[RAW]

For the surging issue, try turning the idle screws in say 1/2 turn. The other problems strange and not a clue.

[KULTULZ]

Curb idle setting on an automatic should be 650-750RPM's. Do you have a dashpot on the application? This may be your stalling problem.

The surge at speed will probably turn out to be a vacuum leak or incorrect/defective power valve. Connect the distributor vacuum advance to ported vacuum and see if there is any difference.

[woodz428]

I would check the power valve because of the other symptoms you've mentioned. I have also had experience with carbs from that company ( I do a lot of 'stang work) and I don't think they make them for daily use, more for pulling show cars on and off trailers. I have had to take both the carbs my customers had purchased apart and correct internal problems. For your needs you'd have been better off and less pocket light by getting an Autozone or equivalent carb.

[KULTULZ]

You know, I have heard this several times before. Kinda makes you wonder what you are paying for.

[Steve B]

Yes, I'd have to admit I would have been just as well off (and richer!) had I simply put a kit in a wrecking yard carb or bought a rebuilt one. I fell for the hype- what can I say? They claim to correct "internal problems" and claimed to jet the thing for the 292, so who knows?

As for the symptoms I described, it turned out to be a simple fix. I tried ported vacuum to the distributor, and the low speed running problem was solved as well as the hot re-start symptom. I'm scatching my head over this, but I guess it has something to do with not enough advance in the first instance, and too much in the other when using manifold vacuum.

Anyway, I don't want to dis Pony carbs- they were very responsive to a couple of smaller issues I had. But if I had to do it again.....

[KULTULZ]

[quote]...but I guess it has something to do with not enough advance in the first instance, and too much in the other when using manifold vacuum.<hr></blockquote>

BINGO! The vacuum advance is always ran off ported vacuum unless it is a special factory emission system.

[quote]Anyway, I don't want to dis Pony carbs- they were very responsive to a couple of smaller issues I had. But if I had to do it again.....<hr></blockquote>

I understand your position exactly, but on the other hand, you could have found base jetting in the FORD Master Parts Catalog for 1957 and gone from there.

The truth of the matter is that the Autolite 2100 and 4100 is one of the esaiest carbs to work with and a properly set up 4100 will out perform a similiar Holley on most street applications.