Autolite 1100 stalls off idle at operating temp

I put a remanufactured Autolite 1100 on my 1965 Mustang 200 I6 and it functions perfectly while cold, but once it warms up, it will stall off idle unless I feather the accelerator. I have done the adjustments but obviously am not doing something right. Any thoughts?

Thanks,
David

What adjustments have you done? Can you take some pictures of your carb and Distribtor and post them?

choke OK in there?
Know about the 'finger' or steps on the external linkage on the side?
Is this w/in 7 min of starting? (Oh, sorry you said 'operating temp'. Well this is you I thought of these things).
What do you See
What do you Smell
What do you Hear
Feel
?
W E L C O M E !!!
and tell us more.

I assume you still have the loadamatic distributor. Does your new carb. have the SCV design?
Need more information on your build.
When you look into the carb. intake, do you see the accelerator pump shooting fuel into the carb. when you open the throttle?
The above needs to be confirmed before we go further.
If your dist. is of loadamatic design, is the vacuum pot moving the advance plate inside the distributor when vacuum is applied with a vacuum pump??????

Thanks all.

I did the bench adjustments per the manual and online videos without result. I am quarantined 2 and a half hours from the car so can't take any pics. I was advised by the reseller that only minor adjustments were needed and I actually broke the pump rod and had to get a new one.

I also had what appeared to be a rebuilt carburetor that was in the trunk that I tried first. It had the same problem but only much worse which is what led me to purchase another one.

The carburetor is a "new" NCI carburetor ( https://www.ebay.com/itm/Ford-Autolite- ... SweLBafiig ).

It has the SVC.

I am seeing a squirt when I barely move the accelerator but it is not really a mist.

I am running a DUI distributor with, 18V VPI and approximately 20 degrees advanced. The original carburetor did not have this problem and ran fairly well but the gaskets were leaking badly. The vacuum line is still running from the carburetor as it was on the original. I have tried it with and without the SVC (port plugged and unplugged) without effect.

I know I probably need to run the vacuum advance from the manifold but have not done so yet since it did not have the problem with the original carburetor. It runs really well under other acceleration and idling conditions.

It happens within the first couple of minutes so actually not at full operating temp. Up until that time it operates perfectly.

If the issue was the vacuum advance, wouldn't I experience issues at other acceleration/rpm conditions?

ci/Loadomatic.html
'the Hand book" from Matt at vintage inlines dot com and the above "tech archive' (blue box w/crossed screwdriver/wrench) are 2 resources many use to get up to speed on these 6 interesting engines (1960 - '96).

I see more of the chebby guys put the DUI on them than I like...

delesher":11trklsu said:

Thanks all.

I did the bench adjustments per the manual and online videos without result. I was advised by the reseller that only minor adjustments were needed

The carburetor is a "new" NCI carburetor, It has the SVC.

I am seeing a squirt when I barely move the accelerator but it is not really a mist.

I am running a DUI distributor with, 18V VPI and approximately 20 degrees advanced. The original carburetor did not have this problem and ran fairly well but the gaskets were leaking badly. The vacuum line is still running from the carburetor as it was on the original. I have tried it with and without the SVC (port plugged and unplugged) without effect.

I know I probably need to run the vacuum advance from the manifold but have not done so yet since it did not have the problem with the original carburetor. It runs really well under other acceleration and idling conditions.

It happens within the first couple of minutes so actually not at full operating temp. Up until that time it operates perfectly.

If the issue was the vacuum advance, wouldn't I experience issues at other acceleration/rpm conditions?

Click to expand...

Thank you for providing all the details it really helps in being able to give you an accurate answer. The long and short of it is that these older carb's with a SCV system won't work correctly with any of the newer distribtor's vaccum advance system, that is unless it's modified. The Ford "Load O Matic" is a unique advance system unlike any other that only works good for a mostly stock engine using a SCV carb and its matching LOM Distribitor. The newer vacuum advance systems are better in both performance and economy and by 1968 Ford had went to the better vacuum advance system (and even earlier in 1966 on the California emissions spec cars).

You have severial choices. Yes you could hook your DUI direct to manifold vaccum. Second since your orginal carb did seem to work well except for leaking gaskets it may have been modded already (without seeing the SCV vacuum ports this is only a guess) so you maybe able put a fresh carb kit in it and be good to go. Third you can do the SCV mod on your new Autolite carb it a fairly easy job see below link "Drop A Load". Last you could use a newer non SCV carb that has the correct ported vacuum source for your distribor of which there are many choices. I have done all these hookups and have my preferences, like mostly only using the carb's ported vacuum advance on a street type daily driven car if you are wanting the best in economy and drivability, (the Autolite 1100's are excellent for economy). Have also used the straight manifold vacuum source for vacuum advance and even no vacuum advance system on a drag race only car. Good luck on your tuning

Drop A Load post by Wsa111
https://www.fordsix.com/viewtopic.php?f ... 21#p591333

You said you have a DUI. 20 degrees initial is way too much. Should be 12-14 degrees with that distributor otherwise you will have too much total advance.
Is the engine completely stock??

bubba22349 - I did the DUI modification myself so I doubt the original carb was modified. Would this cause the issue of stalling when accelerating slowly off idle but running well otherwise? I will try pulling the vacuum off the manifold then modify the carburetor if that doesn't work. In the diagram to your link it looks like you get more vacuum off the carburetor than the manifold. Is that correct and does that make it more preferential?

wsa111 - the dui tech article and some others I've read advise advancing the ignition to the point where the engine knocks under acceleration. I never got to that point and didn't want to go any further. I will also try setting to the factory setting. I think it was 16 degrees for the automatic if I recall correctly. I'll double check my manual.

delesher":26wpkwfr said:

bubba22349 - I did the DUI modification myself so I doubt the original carb was modified. Would this cause the issue of stalling when accelerating slowly off idle but running well otherwise? I will try pulling the vacuum off the manifold then modify the carburetor if that doesn't work. In the diagram to your link it looks like you get more vacuum off the carburetor than the manifold. Is that correct and does that make it more preferential?

wsa111 - the dui tech article and some others I've read advise advancing the ignition to the point where the engine knocks under acceleration. I never got to that point and didn't want to go any further. I will also try setting to the factory setting. I think it was 16 degrees for the automatic if I recall correctly. I'll double check my manual.

Click to expand...

You can throw out the manual, each engine combo requires different distributor curves. And each will require different initial advances.

Sounds like it's going too lean. When it stalls, is it popping or surging, or is it just not revving up ("Falling flat on it's face") and then recovering? Surging/popping is too lean, "falling on it's face" is generally too rich.

* Plug the SCV port in the carburetor and forget it's there - the carb doesn't know or care. (now, if you had a LoM distributor, they care a lot - but you don't)

* Manifold vacuum is best. Ported vacuum was only introduced as a way to increase combustion temps at idle for emissions - nothing else, no matter who says what (my source is one of the GM engineers who worked on ignition systems in the 60's-70's.)

* You should see a nice steady squirt of fuel out of the accelerator pump nozzle just as soon as the throttle moves - like a water squirtgun.

* Given the above checking out, disconnect the accelerator pump and see if/what difference it makes - it'll give you a clue what the engine is wanting. If it then revs good, then the accel pump is flooding too much fuel. If little or no change, then the accel pump is likely not shooting enough fuel.

delesher":3s5plro2 said:

bubba22349 - I did the DUI modification myself so I doubt the original carb was modified. Would this cause the issue of stalling when accelerating slowly off idle but running well otherwise? I will try pulling the vacuum off the manifold then modify the carburetor if that doesn't work. In the diagram to your link it looks like you get more vacuum off the carburetor than the manifold. Is that correct and does that make it more preferential?

wsa111 - the dui tech article and some others I've read advise advancing the ignition to the point where the engine knocks under acceleration. I never got to that point and didn't want to go any further. I will also try setting to the factory setting. I think it was 16 degrees for the automatic if I recall correctly. I'll double check my manual.

Click to expand...

No the purpose of the above mod of converting a SCV carb to a ported vacuum sorce is to have no vacuum advance when the engine is Idleing so it's idleing on just the base timing. Your engine stalling is another seperate issue that's caused by either to much of a accelerator pump shot or to little, what's your accelerator pump setting right now? Good luck.

jamyers":2hwvpp4y said:

Sounds like it's going too lean. When it stalls, is it popping or surging, or is it just not revving up ("Falling flat on it's face") and then recovering? Surging/popping is too lean, "falling on it's face" is generally too rich.

* Plug the SCV port in the carburetor and forget it's there - the carb doesn't know or care. (now, if you had a LoM distributor, they care a lot - but you don't)

* Manifold vacuum is best. Ported vacuum was only introduced as a way to increase combustion temps at idle for emissions - nothing else, no matter who says what (my source is one of the GM engineers who worked on ignition systems in the 60's-70's.)

* You should see a nice steady squirt of fuel out of the accelerator pump nozzle just as soon as the throttle moves - like a water squirtgun.

* Given the above checking out, disconnect the accelerator pump and see if/what difference it makes - it'll give you a clue what the engine is wanting. If it then revs good, then the accel pump is flooding too much fuel. If little or no change, then the accel pump is likely not shooting enough fuel.

Click to expand...

I'll give this a try when I get back to where the car is.

bubba22349":ch9lqfeq said:

delesher":ch9lqfeq said:

bubba22349 - I did the DUI modification myself so I doubt the original carb was modified. Would this cause the issue of stalling when accelerating slowly off idle but running well otherwise? I will try pulling the vacuum off the manifold then modify the carburetor if that doesn't work. In the diagram to your link it looks like you get more vacuum off the carburetor than the manifold. Is that correct and does that make it more preferential?

wsa111 - the dui tech article and some others I've read advise advancing the ignition to the point where the engine knocks under acceleration. I never got to that point and didn't want to go any further. I will also try setting to the factory setting. I think it was 16 degrees for the automatic if I recall correctly. I'll double check my manual.

Click to expand...

No the purpose of the above mod of converting a SCV carb to a ported vacuum sorce is to have no vacuum advance when the engine is Idleing so it's idleing on just the base timing. Your engine stalling is another seperate issue that's caused by either to much of a accelerator pump shot or to little, what's your accelerator pump setting right now? Good luck.

Click to expand...

What do you mean by accelerator pump setting? Are you talking about the high low pin holes on the pump arm? I think it's on the lower if that is what you mean.

Place it in the top hole, that will give you more of a pump shot.

FYI, ran a T off the manifold for distributor vacuum advance and plugged the SVC port and the problem was solved.