rebuilt 72' carb on a 78'2f slight dead spot right off idle? (1 Viewer)

Joined
Mar 20, 2006
Messages
1,821
Location
elkcreek canyon colorado
this carb has been gone through (last week) by a good carb guy. It is on a 78' 2f, vac. advance moves inside the dizzy like it should, hooked the 78' ignition and ignitor up to one hot ingnition wire, truck idles and runs very strong/smooth but there is an area just off idle where it drops on its face and then comes back to life very abruptly. Carb guy thinks it just the transfer from idle circut to power circut, I have owned a lot of 40's and never had this issue. there are no vac leaks and the timing is set about 5 dgrees adv., where it seems to idle the smoothest. Also it only seems to do this under load, it revs up fine in neutral. Ideas?????
 
Joined
Jun 8, 2007
Messages
478
hmmm, sounds just like my 72. I'll be keeping an eye on this thread. FYI, everytime I start it up, it will do this; fall on it's face just above idle BUT has no problems if I slowly press the gas. I figured its a dirty carb issue. I've already replaced the cap/rotor, plugs, wires but have yet to replace the points. After gunning it (not too much) for about 20 seconds I have no problems.

Is this the same problem you're having?
 
Joined
Mar 20, 2006
Messages
1,821
Location
elkcreek canyon colorado
No mine does it no matter how warm the motor is, You can be in 3rd gear coasting and just start to push on the gas, and DEAD then BOOM back to life and runs great. Drives me nutz!
 
Joined
Jan 22, 2003
Messages
8,118
Location
Kansastitty
My guess is the accellerator pump is bad or not adjusted. You just bend the rod to get the pump to engage sooner.

GL

Ed
 
Joined
Mar 20, 2006
Messages
1,821
Location
elkcreek canyon colorado
Hmmmm....... accellerator pump, the linkage does look a little tweaked, I will try to adj. that today. I thought the only selinoid on the carb was the fuel cut off????
 
Joined
Feb 6, 2002
Messages
15,219
Location
OC, CA
The transition slot provides the most of the fuel during the initial opening of the throttle plate. Either the transition slot is plugged or the idle fuel circuit isn't providing enough fuel flow to keep up. Maybe a bad fuel solenoid or dirt in there somewhere.

Carb2%20026%20copy.jpg
 

n2666s

SILVER Star
Joined
Feb 21, 2006
Messages
2,668
thinking of installing an F carb on a 2F manifold....what was the final outcome to this problem?..TIA.

Lou
 

Users who are viewing this thread

Top Bottom