I have a 1974 360 and As many of you may know from my latest post I have been having trouble with my engine timing. What my exact problem is is that when you are going down the road at a steady speed and then get on the gas the engine starts to shutter. almost like a cylinder not firing on a 6-cyl. just not that hard of a shutter. I have been thinking that it has something to do with my timing but now i am begining to wonder. I have tried every possible timing setting from 6-20 deg. with absolutely no change. right now i have it set at 12 deg.with the engine idling at 12 deg. I can give it gas andwatch it advance to about 30-35 deg(with vac.adv. unhooked) and it runs good and smooth. but when you put the engine under load it starts to shutter. could this be something else other than timing.
BTW: I have new plugs,wires,points, condenser,rotor, and cap.
this is also an extremmely heavy truck F-350-dually-with flatbed

 

This has symptoms of a lean condition. check accelerator pump and check for a vacuum leak. A 74 should have an egr valve, and this is a place to check for a vacuum leak. the plate between the carb and mainfold can "rot" thus causing a vacuum leak also. get a spray can of carb cleaner, spray around suspected areas while engine is running. you will notice a difference in idle if there is a vacumm leak. feel free to e-mail me.

Wayne 60 F-350
e-mail
https://www.ford-trucks.com/users/whomrig

 

i tuned my carb mixture with a vacuum gauge- hook it up, and dial till you get the most vacuum you can.

worked like a charm, as i had no other way to figure out how to adjust the mixture.

 

I tried to tune the mixtures and still had no luck. I have taken and plugged all of the hoses coming from the carb. and the egr plate is good so no vacuum leaks that I can tell. as for the mixture needles I have turned them to all sorts of settings and still no luck. Also as you are standing in front of the truck, which screw is gas mixture I assumed it is the one on the right but I can't verify it. It is a motorcraft 2100 carb
any help would be appreciated

 

Dr.Ford- I had a similar but not as severe a feel. Did all of the timing jazz, all of the vacuum tuning, all of the mixture screw stuff and it really never got perfect. Finally got rid of the points and did the Flame Thrower coil and things are real good right now! Might want to give it a try, real easy installation.



1971 F-350 1 ton dump, ground up fully restored w/ 360 motor

 

Just what are the usual settings for the mixture needles on this engine/carb.

 

Adjusting your idle mixture screws will have little to no effect on part throttle operation. But it does sound like the engine is starving for fuel. I would also check your acelerator pump. May be time for a carb rebuild.