I have been having an idling problem with my L69 since I first bought it. It starts right up, and idles fine as long as it is on the high idle cam. Once it gets to Operating Temp, sometimes it will idle fine, sometimes it wants to idle down and die. It runs very strong when accelerating, and pulls very strong at WOT. When I am just cruising along, it sometimes wants to hang on high idle even when at Op Temp. When I blip the throttle, it sometimes wants to idle down and die. This has become very frustrating making me reluctant to even drive the car.

1966 E block 400, .030 over, B heads, mild head work done, Erson cam, springs, rockers & pushrods from Cutlassefi, Cloyes Hex-adjust double roller timing chain, stock Distributor with Pertronix Igniter II, new rotor, cap, wires, AZ manifold.

The Carbs have been professionally restored to like new condition. I have disassembled the center carb a couple of times looking to see if I could find anything amiss, but all looks well. I did install a new gasket just to be sure. New float, set correctly. Motor does not starve for fuel during WOT. The throttle shaft is not binding, nor are the blades hitting anything. Return Spring is strong. No fuel leaks visible.

I have tried just about every variation I can think of to identify the problem but I have stricken out:
Tried with Vacuum Advance, without Vacuum Advance, timing at every step from 6º advanced to 20º advanced. Gas is fresh 91 octane, tank is clean. I have noticed that the idle adjustment screws don’t seem to hit a real sweet spot, it just kind of idles the same then dies when the screws are almost all the way in.

I am looking for some help from the pro’s here.

 

I have helped a lot of people with this. It seems that when people take off and replace the carbs they are shifted a little.


3/4 of the time just take off the front carb to back carb rod clip(Passenger side) so that at wide open throttle only the middle and front carbs would open. You could drive it if you wanted to but DON"T wide open throttle it.


Anyway push the throttles on F&B carbs forward, with that rod see if the rod will go right into the hole. Like I said most of the time it will be short, meaning that the front or rear carb is open a little bit and feeding more gas. Bend it in the middle to make it fit.


The front and back carbs are either OFF or ON, they do not idle.


Try that first.


Mike

 

If the carbs are running off idle fine and act up in idle then your issue is in the idle circuit. Like was stated above the front and rear carb should be off at idle, butterflies closed. If you look down into the throats of the carbs at idle do you see any fuel dribbling?

 

The front and back carbs are off, rod moves freely side to side, holes line up perfectly.

 

Same problem has plagued this motor even before restoration......... a vacuum leak would/should always be present and have a constant effect. This comes and goes.
Timing has had no effect on how the idle problem behaves.
No fuel dribbling. I agree with your assessment. How to fix?

 

I wonder if the rebuilder mixed your carb parts. Here is a good article:

http://www.hotrod.com/techarticles/e...32_ford_coupe/

 

Great article. The 2G and 2GC carbs are very simple, and there are really no critical parts that could be mixed. I will check the throttle blade fit one more time, although I checked them when I got them back from the rebuilder.

 

Have you tried running it with the outer carbs disconnected to see if it has any effect?

 

You also mentioned your timing between 6 degrees and 20 which I'm assuming is initial and your total mechanical. You don't think that is a bit low? I wonder if you raise the initial up a couple of degrees, your base idle will follow and enable you to crank the idle speed adjustment screw out a bit and possibly get the butterfly back into the idle circuit?

 

I would suggest removing front and rear carb. Blocking off the intake and then setting up the center carb. Make a couple of plates. This completely eliminates them as a possible problem