Autolite 1100 Carburator parts

[Nathan289]

Roger,

I feel your pain. I bought 3 supposedly rebuilt 1100s for the 62 wagon years ago. Some of these rebuilds I was getting from rebuild shops were horrible. I robbed them of parts and sent them back with notes showing them how they weren't right.
I believe I ended up finding a solid core off an econoline van.

Ive even taken running 1100s into carb rebuilders to get them back and they wont run. I've come to the conclusion that carbs are a bitch.

Problem is the Holleys aren't much better but classic in lines sells an all brand new Holley clone. The problem is it requires a distributor swap (more $) that distributor swap will be a later 5/16 oil pump drive shaft not the early 1/4. So swapping oil pumps would also be required. Have you priced I6 oil pumps?

So by the time im finished with the swap it would be over $600

If thats what I have to do I will but im not at that point yet.

Whats bugging me is yesterday it fired up, once warm ran great. Drove it around the block. Came home shut it off, took a 15 minute break came back out started it up and it wouldn't idle again. I kept it running for a while but I eventually let it die.
pulled plugs and they looked lean. Last time it did this they were rich. So I dont get it. Something in the carb either changes or something in the ignition system changes.
I need to put a dwell meter on it and see what I have going on.

it also sounds like I have a miss.

[Luva65wagon]

Here's an image of the idle circuit. It does use the main jet as a feed source, so the idle bleed sizing, etc., may not be matched for the jet as you have it now. How much bigger did you make it?

I did some checking last night as I was digging through all the carb parts I have (have I mentioned I have a lot of them now?) and it seems the number actually represents the size in thousands of an inch. So a 58 is .058 and 62 is .062 and so on. So a 58 can be made a 59, but a 62 can't be made a 59. And these would be reamed sizes. Using drill bits, in brass, can rip the holes way bigger than the drill size.

The 1100 also suffers from potential internal and external vacuum leaks. The power valve circuit is just under the larger vacuum plug (expanded into the hole in the top of the carb). These are almost always buggered up and so I replace them and apply a small bead of JB Weld to make them totally vacuum tight. I've also found, even at best, these valve hang up. You can't pull them out, so you can only clean them and hope for the best. I use a vacuum tester/brake bleeder and test these thoroughly now.

And yes, I went over all of this spark control stuff and what would be required to negate it (oil pump, shaft, distributor with mechanical and vacuum advance) when lamenting over the carb issues with that Comet last year. It's not easy to doing something stock anymore. That's why I, and many others, upgraded to a Weber, electronic ignition, etc. It can be done stock, but it's not as easy as it once was when everything was new.

[Nathan289]

When rebuilding my carb, I took the jet out and sized it with a number drill bit. I then used the next size drill bit to enlarge the jet.

You wouldn't think it would make a huge difference but maybe.

The funny thing is when I removed the plugs yesterday they now looked lean?
So I'm confused as why it was running rich earlier.. plugs were sooted.

I've changed so much stuff I don't know when and where I went from rich to lean.

I do have a miss in it so I wonder if the miss is because its lean now?

[Luva65wagon]

That power valve depends on full vacuum at idle to pull that plunger inside up hard against the ball and close off the main jet. If that isn't happening correctly the thing could be sucking fuel past the main jet when it shouldn't.

This is the hardest part of this carb to deal with since you can't [really] pull that section of the carb apart. As long as it seems to move freely by hand applying light pressure to it and letting it go - and the plug on the top of the carb isn't leaking - it should close off. But you can't inspect the ball or the seat to see whether, even if the ball goes up against it, it will stop the flow of fuel. I took to turning the bowl over, using a drift, and pressing the lever end against the ball and giving it a light whack with a hammer to seat that ball a few times. Then before assembling it all I used a suction in the correct hole (and plugging off another in the same circuit) and sucked to see if the lever lifted. When it did a few times in a row - I called it good.

Of course I knew none of this last year. I spent many hours standing at the bench studying this thing.

[Nathan289]

I seem to be running lean now.

Im wondering if the initial rich reading was from the plugs not getting cleaned yet from running retarded.

I pulled the original fouled plugs yesterday and they look like its lean now.
I put in new plugs a heat range colder and ran it today for 30 minutes and they came out as clean as when I installed them.

I'm going to tear the carb apart and try again..

Im also going to study the distributor tear down section in the manual. If I can by a new distributor without the spark control valve but put the smaller drive shaft gear from my distributor, I might buy the new Holley clone.

Nathan

[Nathan289]

Roger,

I think I found my problem..

I had someone tell me to try and set the initial timing at 16-18* with vacuum disconnected..

So I did that.. what I found is, I must have fiddled with timing with vacuum hooked up. Because with the vacuum disconnected it was retarded..

At 16* I had a knock.. not sure it was from timing or from fuel pump, but I didn't like it. So I backed off timing to 10* knock went away.. I then adjusted idle and mixture.. I lowered idle down and it started to roll, so I'd trim the fuel mixture and rpms would pick back up. I did this multiple times until I got the mixture screw about 2 turns out and idle speed was at 650.

I then bumped timing down to 8* and fine tuned the mixture and speed.

I hooked up the vacuum advance, everything was good until I reved the engine.. timing jumped to 20* rpms jumped to 1180 and it stayed there..

Wouldn't drop. I had to disconnect vacuum for the rpms and timing to go back to normal.

I think I have a bad distributor. Its original wouldn't surprise me if it needed replacement.

Not sure if its the springs inside, diaphragm, or binding but I think I found my problem.. if so its cheaper than a new carb.

Well I'm on my first night of graves for awhile, distributor won't be fixed for awhile.

Nathan

[Luva65wagon]

I believe there's a spring in the vacuum diaphragm of the distributor. But it looks like you're on to something. With the car off, cap off, work the point plate by hand and see if you move it towards the vacuum diaphragm and let go, it should return on it's own. If not, it may be a gummed or binding point plate or the diaphragm is bad.

The other jet is on the way - so if you use it great. If you don't need it, hold on to it - I may need it again.