Poorly running fresh rebuilt 292
 

Sorry this is so long but I wanted to provide all the info I have available.

Background:
1959 Edsel Ranger, 292, 2sp auto. 99.9% complete and all original car. Previous owner died unexpectedly 50 years ago and it has not run since.

Engine is freshly rebuilt. I had a trusted local machine shop clean and machine the block and crank. Block 0.030 over and crank 0.010 under. I did the assembly - I've done several but this is my first y-block.

The engine has new pistons, rings and bushing. New main, rod and cam bearings, new timing chain set (counted pins several times and followed the manual), new oil pump, new fuel pump (vacuum wiper version). Heads have been cleaned, valves cleaned and seats hand honed, new valve stem seals, valve springs and keepers. Replacement used rocker arms.

I cleaned and rebuilt the original Ford 2 barrel. It's now very clean and all passages in the body are clear. Main jets are #48s (correct for 0-5000ft according to the manual). Installed a new power valve, needle and seat and all new gaskets/screw washers. I did place the backflow balls in the ventura main screw hole and in the screw hole on the power valve screw. The float does not leak and is adjusted correctly according to the manual 0.45" float to top of carb body and fuel level about 0.91" below top of body (removed horn and checked).

And of course, new plugs, wires and coil (internal resistor and I jumped passed the firewall resistor), cap, rotor, points, condenser.

Compression is good, all cylinders are between 145-155. It's only been run for 10-15 minutes total so far so rings may not be fully seated yet.

Ok finally, here's the problem:
The engine starts but does not run well. It will not idle below about 1100 RPM, it stalls. It does rev fine if I open the throttle. The timing is pretty close but it's hard to get it exact with the engine running like this. Also, running like this I cannot adjust the idle mixture screws as they are not responsive at 1100+ rpm because that's above the idle circuit speed.

I have very good fuel flow from the fuel pump and there is plenty of fuel when I open the throttle so it's not a fuel delivery problem.

After a few minutes of warm up (still running poorly) if I close the choke butterfly manually without engaging the fast idle cam, the engine speeds up and smooths out. I expected closing the choke would kill the engine so I guess I have a vacuum/intake leak. With the choke almost all the way closed I can then adjust the idle down to about 700rpm (in park) and it runs pretty well.

There are only two vacuum ports/lines on it. Top of the manifold to the fuel pump and the carb to distributor vacuum advance hard line. Neither of these is leaking. The intake manifold fit well when I installed it with new gaskets. The intake manifold does have two thin metal round (1-1 1/4") mushroom caps on the sides - what are they for?

I did connect a vacuum gauge to the line coming from the top of the manifold. It's reading 12-15 when the choke is open at 1100 rpm but reads 20 or a little more with the choke closed and the idle at 700.

I can't find any leaks! Any ideas are welcome

Re: Poorly running fresh rebuilt 292
 

The "mushroom caps" on the manifold are part of the heat riser automatic choke system. There is a metal cross-tube inside the manifold that is also part of the choke system. Often those tubes have disintegrated, but they can be replaced. If you look on the passenger-side exhaust manifold, you should find what looks like a spacer, where the down pipe joins the manifold. That spacer is the exhaust choke valve. It could be that your problem lies somewhere within the choke system. I would beg, borrow, or steal a proven carburetor/w electric choke, and see if that fixes your problem. Best to focus on one thing at a time.

Re: Poorly running fresh rebuilt 292
 

I stripped the whole car to restore it. I pulled the exhaust "heater" valve and of course it was stuck. I got it freed up enough to move but ended up cutting the flap out of it so the exhaust is open. I left the shaft in so I don't have a leak. Macs offers a spacer without flap so I'm not the only one who has removed it.

I don't think the problem is with the choke. After warmup the engine still runs poorly with the choke totally disengaged. It seems to be running too lean because cutting the air flow down (closing choke butterfly or putting a hand over the carb opening) increases the engine speed and smooths it out.

I do have another Ford 2 barrel, I think from a mid 60's car. Of course it needs to be rebuilt. Carb kits are cheap so maybe I'll just do it and see if it makes a difference. It's a little different but I think the mounting is the same.

Don't have access to any other carbs right now. They are getting scarce.

Re: Poorly running fresh rebuilt 292
 

A lean idle mixture should increase idle speed/cause idle surge. An overly rich mixture would have the opposite effect. Have you inspected the plugs? I would still try to source a carburetor from a running engine before rebuilding another carburetor. Are there any car clubs in your area? Maybe they can help.

Re: Poorly running fresh rebuilt 292
 

I took the ventura out of my old spare mid 60s carb, cleaned it really well and swapped it into the original Edsel carb that was on the car.

Wow, it runs much better now. I was able to drop the idle to 625 in park and set the timing at 8 degree BTDC with the vacuum advance disconnected and plugged. The manual says 6-10 so I put it in the middle until I can get the carb working correctly and can drive it a little.

Adjusting the mixing screws still has no effect. I'm going to find a replacement carb...

Re: Poorly running fresh rebuilt 292
 

First, do this; with engine off, turn the carburator idle-fuel mixture screws in all the way till they stop (lightly), then back them off one and one half revolutions. That is your starting point for the idle-fuel mixture adjustment. Start engine and run till warmed up. Now fine tune idle-fuel mixture using a vacuum guage connected to manifold vacuum. Turn screws till you get highest manifold vacuum AND smoothest idle.
Also, did you adjust valve lash properly. Should use .019" feeler guage with engine hot for all valves intake and exhaust. If valves are too tight, it will run crappy. If waaay too tight, will bend push rods, too loose tappets will be too NOISY and engine will not perform well either.

Re: Poorly running fresh rebuilt 292
 

Yes, I've adjusted the valves to 0.019 hot, they were very close after the cold prelim setting of 0.018, only had to adjust a thousand or 2 and a few valves.

And yes, I did start the carb screws at 1 1/2. The problem now is turning them does not have any effect on the vacuum or how the engine is running. I can even turn them all the way in and the engine will keep running.

I have not found any intake/vacuum leaks so I'm guessing something is still wrong with the carb and I'm working on finding a replacement.

In any case, it is running well enough to drive now.

Re: Poorly running fresh rebuilt 292
 

idle circuit is plugged up or its possible wrong gaskets. Carb kits usually have
many gaskets your idle circuit probably covered up by the wrong lower gasket

Re: Poorly running fresh rebuilt 292
 

That says its starving it should be around 20 inches.......

Re: Poorly running fresh rebuilt 292
 

I'd check the gaskets below the carb. some rebuild kits don't match the carb bases and leave gaps

Re: Poorly running fresh rebuilt 292
 

I had the same problem and it drove me crazy. Turns out i had plugged fuel feeds to the idle jets. No high pressure air will blow it out unless you take the carb off and leaving the jets in but backed out a couple turns high pressure air might work. It did for me. Another time i revved the motor wide open and choke it with a rag or anything choking it to quit instantly. Sounds crazy but it sucked the dirt out. Don't forgget to readjust idle once you restart it.

Re: Poorly running fresh rebuilt 292
 

It does sound like a gross vacuum leak. With the engine running and air cleaner off, also plug any open vacuum ports, place a hand over the top of the carburetor. If the idle picks up and smooths out, you have a vacuum leak.

Spray some carb cleaner around the base of the carburetor, again if the idle gets better, you have found the leak.

Re: Poorly running fresh rebuilt 292
 

really sounds like a little bit of everything? vacuum leaks checked by the brake booster? disconnect and plug everything before spraying carb cleaner etc around intake/carb. throttle or choke shafts on the carb? very good idea to go back over the valves now after a couple heat cycles. vacuum gauge should be steady, never erratic. if any surfaces were milled heads/intake it may be leaking under the intake/valleypan?