411111111mycat. I am having trouble setting up my timing on my fresh 312. The damper only has one mark for timing, and after it warms up and I shut it down it diesels. It starts up easy and runs great for having a two barrel. But the dieseling has me concerned. The Idle doesn't smooth out until about 1100-1200 RPM. Any Ideals.

 

In Part>>and after it warms up and I shut it down it diesels.....

Sounds like the throtle plate in the carb is open too far.
Reduce the idle speed and reset the idle mixture screws. BOTH idle screws should be set equal.like 1 1/2 turns...
you can increase the timing as long as it does not `pink` under axceleration.
I would use a vacuum gauge to adjust the carb FIRST. then set the idle speed (hot). then go for the timing At Idle I would not go more than 1" advanced from the `Mark` that is there now ..At least till you get things settled down...

My .02



__JOHN__Õ¿ö
Member-
"Crusin North" Car Club
Santa Rosa, Calif.
72 F-250
ICQ#6030753
https://www.ford-trucks.com/pictorial/big/1972_f250_2.html

 

yup, what he said.

It's a new engine, correct? so the dieseling isn't like carbon buildup or anything....?

-Andrew
f250_64(No Email Addresses In Posts!), same for yahoo messenger

Nothing, and I mean nothing, stirs the soul, saying I'm a bad **** like lettin'em rip with a window shaking, fuel gulpin, carbon monoxide belchin, attention gettin, V-oh my LORD!-8!

 

sounds like you could have a number of things wrong. Two of the most common problems are related to one-another. One, as previously mentioned, could be the throttle being open too far. The other could be a vacuum leak somewhere. If there is a vacuum leak, the engine will idle funny, run find under a load, because there is little if any vacuum. The throttle could be open too far as a result of turning in the adjustment screw in order to compensate for the vacuum leak. just my $.02
anyone wanna add to that?

 

>411111111mycat. I am having trouble
>setting up my timing on
>my fresh 312. The
>damper only has one mark
>for timing, and after it
>warms up and I shut
>it down it diesels.
>It starts up easy and
>runs great for having a
>two barrel. But the
>dieseling has me concerned.
>The Idle doesn't smooth out
>until about 1100-1200 RPM.
>Any Ideals.


Could be improperly adjusted lifters. Lash should be .018 hot and running. The dieseling may be due to an overadjusted valve or the idle is too high. Worth checking.
Good Luck

 

Carb blades open too far with possible vacuum leak is my vote.
Problem is, your idle screws probably won't have much affect
until you get the throttle closed a little more because you
are drawing fuel from the main jets in the carb and not the
idle circuit. Try to set the timing by ear and see if it will
run better. Run it as advanced as possible without pinging
and hard starting when hot.

 

Thanks for the input guys, I haven't been able to play with the truck because I moved this weekend, plus I just received my 4 bbl. and I plan on installing as soon as I can find my garage. I did find a big room with a concrete floor full of boxes and stuff and I get the feeling my spousal unit wants me to play there.