still having carb trouble - vent valve to blame?

[Vaughan_D_W]

Ok, so I rebuilt a 200 to replace the 144 that was in my Mustang when I got it. I got the engine running. I used the carb off the old 144 because I know it was good enough to make the car run. However, I also have another carb with a bigger venturi that came with the 200 I bought. Both are Autolite 1100s. When I had the 144, the car would run and idle, but it would sputter and buck under throttle, and stall out. UNLESS I put the choke halfway on. Then it would run, but had very little power. Now, I have the same thing happening with this 200, using this same carb! So something is wrong with that carb, and now I'm looking at cleaning up the other carb I have, and putting that on the car.

BUT, there is something not quite right with both these carbs. It involves what a Google search has informed me are parts called the vent valve and vent valve rod. The carb from the 144 (the one I've been using) has the vent valve plugged up with a bolt forced into the opening. The carb from the 200 (the one I want to freshen up and put on the car) has a broken vent valve rod. The rod is just hanging off the actuating lever, and the other half is missing. The vent hole in the carb body is open, and there is a spring inside.

Anybody know what's going on? Does this have anything to do with my problems? How can I fix this?

 

[xctasy]

You have to go through the whole thing. Sound like the fuel pump pressure may have exceeded the stock levels for the old 144 carb, and some one has put a screw in to stop it leaking. Video 9 covers what may have happened in the past with that.

Although a very well designed carb with some simply brilliant features, overall they are a problem carb in that they have so many small parts (in some cases, you'll find four checkballs, four check weights), and sooooo many production variances!. The plastic venturi was a sensational idea, which allowed it to fit anything from 144 to 250 cubic inches, 85 to 155 gross hp.

Even Ford, with its sensational depth of great engineers, eventually bailed out on them, and authorized a Holley 1940 replacement with small and large venturi replacements from 1970 to 1977.

Normally, even if 100% stock, any aged 1-bbl carbs are very hard to tune, as Ford had so many changes between the years as they fitted so many different six cylinder engines. The cfm rating changed, the SCV changed, the hot air autochoke or manual choke. The post 1965 needle and seat.



Normally its the pervious reworks with stuff that shoudn't ever be used in carb service, WD 40 and teflon tape. Modern ethonol fuel reacts very badly with this stuff. Instead, use silicon spray and liquid teflon only.

There has never been a better time to get great info on the 1100 carb.

Read thru these nine video posts:-
1.Autolite 1100 Carburetor Rebuild - Part 1 Teardown
https://www.youtube.com/watch?v=eAirfexkMVY

2.Autolite 1100 1 Barrel Carburetor Power Valve Repair
https://www.youtube.com/watch?v=R8XilvWkP3k


3. Autolite 1100 Rebuild - Float & Needle and Seat
https://www.youtube.com/watch?v=96wm8kcTAYI

4.Autolite 1100 Rebuild - Float & Needle and Seat
https://www.youtube.com/watch?v=8bgc21iYKyY

5.Autolite 1100 1 Barrel Automatic Choke Operation
https://www.youtube.com/watch?v=ZaDyq137YGI

6. Autolite 1100 Carburetor Kit
https://www.youtube.com/watch?v=n8L2RfnG_90


7. Autolite 1100 Carburetor on Bench Adjustments
https://www.youtube.com/watch?v=fVbZ1W1 ... m5IhAqCMIC

8. Autolite 1100 Choke Thermostat TH1045 (Big One only)
https://www.youtube.com/watch?v=A9Tkb_h ... IC&index=8

9. Autolite 1100 Flooding Troubleshooting
https://www.youtube.com/watch?v=QrvsdDu ... m5IhAqCMIC

When circumstances allow, buy a standard # 436 kit or perhpas the premimum kit (called a Hardware kit) from Mike.

These videos will help you trouble shoot.

The info he gives is just increadible, and should be rewarded with patronage if you can.


We live in a modern age where info like this is so free, and this will help you.

 

[78merKri6]

Vaughn D. W.

The Autolite 1100 is a good carb. However, it has some hidden passages inside the tower that holds the mainjet. With age and sitting unused, stale and sour fuel plugs these important passages. One is horizontal under the small steel cup-plug on the side of the main metering well/main jet tower: Use 1/16 or so drill bit into cup-plug,twist in a small sheetmetal screw and work the plug out. This hole is straight in under cup-plug in side of well body. The other passage is straight in under the lead plug that is in the tip of the well/tower. Use a small drill bit (maybe 1/8') to get this lead plug out.

You can use torch tip cleaners to open these passages. Just clean only, don't increase size. Pics would help, sorry I don't know how to post pics.

Some strong carb cleaner might soak these places open. Try that first with compressed air.

If the vent is open, it shouldn't hurt engine running but being plugged probably will. Neither way is ideal but mine is lost & gone,doesn't seem to hurt. By the way, Mike at Classic Inlines will take 'em if you can't use 'em.

Save those carbs and good luck.

Gary

 

[78merKri6]

Vaughn,

I forgot to mention--- reseal drilled holes with fishing sinkers and epoxy. This isn't too hard a job.



X is a great help. He's a living encyclopedia. If you're using a kit, study the checkball locations carefully and don't dismay.

Gary

 

[Vaughan_D_W]

Thank you for all the informative and helpful posts. I'll be sure to review those videos.

I took the carb apart today and ended up making one good carb out of two. The first carb that was on the car had a sticking power valve assembly and was missing the accelerator pump weight. I left the bottom of the carb on the car, added the weight from the second carb, swapped the jet from the first carb onto the second, and put the top of the second carb on the bottom of the first. Of course, I cleaned up the carb top a bit first, even though it was already very clean.

No more stumbling and stalling when I mash the go pedal now! I can actually spin the tires!

Of course, I then got cocky and tried to install a set of cheap gauges, got in a hurry, and broke off the water temp sensor adapter in the head. Can't win them all, huh?

 

[xctasy]

Oh well, LOL, 'tis the season of joy and merriment....


The stock early Ford I6 heads had 1/2" holes for water temperature sensors, and they are cheap and plentifull, so you won't have a problem tracking down an NTC sensor. Ford used the same internal 6 volt electric system from 1932 to 1985 ish.

There were some 1965 and 1969 changes, but it looks like after 9/1/65, the US 200, 289, 302 and 390 and other Mustangs till 1973 had the same SKU: 103278 Part No: C6DZ-10884-B or C9DZ-10884-A Water Temperature Sending for non tach applications. You won't havea problem.

For me, Aussie heads changed to a tiny 1/8" sesnor in 1968, while US sesnors went up to 9/16" sometime before the Fox Mustang, and made my life quite difficult...

My later 81 Mustang then required a 1/2" to 9/16" adaptor to fit its 1963 cylider head I decided to use...since Ford US changed the later models log head casting temperature gage sensor size, i had to make that adaptor up from an aftermarket Hydraulic coupling supply part. But basically, if you can fit it in, any pre 1985 US sensor should do.

See http://fordsix.com/forum/viewtopic.php?f=7&t=71215


Drilling it out a temp adaptor when broken, well, I'd overfill the radiator with a garden hose, turn the water on, and drill the sensor adaptor out with a hand tap and die set, small first. Some have a small wheel or you can turn it with a crescent. Water will push the swarf out. Eventually, it should come out. Its in a very bad spot for easy access.

 

[Vaughan_D_W]

I'm not using original Ford electrical gauges, but rather aftermarket mechanical gauges. So I have a temp sensor that goes through a hollow bolt that threads into the hole in the head. That broke, so now I have a hollow bolt with no bolt head, stuck in my head! If that makes sense . . . Gotta figure out how to get it out.

 

[xctasy]

Try one of these recomendations.

viewtopic.php?f=1&t=10352