I have a 78 F150 w/ a 351M and C6 auto trans. While taking off at a 4 way stop(after creeping for a good 5 or 10 minutes in traffic) my truck sputtered and was surging then died. I rolled it to a stop and put it in park and restarted it with no problem. Then it went a few yards sputtered and died. It did this three more times then I called a tow truck to get it home. I was told by the tow truck driver that it sounded like vapor lock.
The previous owner told me that the carb was rebuilt once. So I went ahead a bought a reman one from AutoZone and installed it. Went smoothly. Only had to plug one extra hole. Only problem is that there was a rusted out metal line from the intake to the back/bottom of the choke housing. One end went to what looks like a plate held to the intake with two bolts and has two metal lines welded to it and they both go to the carb. One line was in great condition and connected to the carb with no problem. I didn't connect the choke to the rusted out line. I am assuming that I will need a whole new two vacuum line piece to bolt back onto the manifold?

I put everything back together, including all springs, hoses, wires, new gasket, new carb. Then started her up after a little cranking. Now she sits at a pretty rough idle. What is the problem? Is that one line to the manifold the culprit? This is my daily transportation. Any help appreciated!!!

I'm gonna go read my Haynes manual now to see if I can find the problem.

 

did u mess with the idle mixture on the nw carb?

1985 F-150/351Ho/c6/4wd~94,000 miles
1979 F-150extcab4x4/460/c6/6inchlift w/60rear44frnt (250 axles and springs)
37 inch boggers

 

 

One of those lines is the hot air intake for the choke. Both probably have vacuum in them i.e. a vacuum leak if not sealed. Idle mixture would have to be adjusted.

1977 Ford F-100
400m/c6/4:11/Gear Vender O.D.
Crane hydralic roller, forged, ported polished,Deamon,Edlebrock, yada, yada, yada
280,000 miles
Stock on the outside
modified/rebuilt everything

 

No, I have not adjusted any screws on the new carb. I just bolted it in place of the old one, and with a new gasket. Is it possible that I would need to 'fine tune' the new carb for my engine?

Dang, Ford does not make those carb choke heater tubes anymore. I bought a generic kit from Autozone that will hopefully fix the rough idle. I'll be putting it on tomorrow.

 

Almost a must every time you change carbs, unless you get lucky.
Checkout this page it has the basics of carb tuning explained very well.

http://www.public.iastate.edu/~wish/Tech/Tuneup/tune.html

Sparky

 

Well, I finally had time to shape and install that generic choke heater tube kit. I also had to adjust the idle screw on the new carb to get the engine running smoothly. I guess even the new carbs need fine tuning on some vehicles. Now I've got to stop an oil leak on the right rear corner of the engine.

Thanks for the suggestions ya'll.