Def could use some advice on this one lol. 55 292 with an auto trans. Magspark distributor ( no vac advance). Sprang for the mummert low rise intake. A close friend gave me a brand new edelbrock 1406 electric choke. Got it all installed and dialed it timing at app 6 degrees. Have idle mixture screws right around two turns out. Spent quite a bit of time ensuring no vac leaks anywhere. Idles great and off idle seems Good as the accel pump kicks in. Under load, like mid throttle taking off from a stop, falls on its face and starts breaking up. Pulled plugs, color looks good and doesn't seem to be rich or too lean.

I know the carb is probably a bit much in terms of cfm but.... Wouldn't think it would be drastic an effect on drive ability. It breaks up so much so that without some feathering of the throttle is may stall

Any help would be greatly appreciated

For starters, I think the Edelbrock site has the manual for that carb. Check the main jets, rods, and springs. I used one on a stock 292 and it ran fine out of the box. But with a larger motor, and eventually a Paxton, the jets got charged substantially. You need to know what's in the carb if its been used. And these are easy to work on if you start with a known baseline.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

Bad ignition, lean, or rich power mode, if you have it floored, maybe the secondary air valve is just not right for your combo and causing the stumble. That last one was my most significant problem when I was running an Edelbrock.



Did you change the distributor, intake, carb, and timing all at once or is it only the intake and carb that is new a new addition and everything else was working just fine before?


Lawrenceville, GA

The carb was brand new in the box. All the internals are factory. The intake and the carb ate the only changes. I adjusted timing only after the new carb was on and it didn't drive that well. What was your solution for the secondary pump issue u had?

The Edelbrock site notes that carb is jetted 2% leaner than the 1405. I don't think that would cause this problem. But I've had at least a couple new carbs that didn't have the "right" jets installed at the factory. If you think you've eliminated other problems, take a close look at the manual and check the jets, rods, springs etc. You can pull the top off so easy, check the floats and look at the internals. They are very forgiving carbs, and should provide good all around drivability.

miker
55 bird, 32 cabrio F code
Kent, WA
Tucson, AZ

I will pull it apart tomorrow and double check everything. Thanks! I'll let u know what I find

Use a Holley.

The solution is to grind some weight off of the counter weights but it's a lot of trial and error. If you go too far, it's difficult to correct. And I wondered, if I modify it, will it now only work with this combo so that I'd have a carb that may be difficult to use on anything else.



If it is "out of the box" it probably needs tuning. It's a universal carb and is not set up specifically for your engine.


Lawrenceville, GA

You say 55 and you only changed carb and intake? you have to change distributor to 57 or later to match the carb! 55 has vacuum only signal and you need one with vacuum and mechanical advance.

55 Vicky & customline

58 Rack Dump, 55 F350 yard truck, 57 F100

59 & 61 P 400's, 58 F100 custom cab, 69 F100, 79 F150, 82 F600 ramp truck, 90 mustang conv 7 up, 94 Mustang, Should I continue?

He has a Magspark that should cover the distributor issue.


Lawrenceville, GA

Finally got a chance to pull the carb apart. The jets and rods are the correct sizes for stock but the springs are not the right color according to the manual. Have to grab a spring kit and start there. Thanks for the replies. I will let u know the results