O.T.: Anyone have any experience with 1974 Ford Bronco

[Rodger Tellefson]

Our daughter has a '74 Bronco that is having carburator issues. It is a two barrel carb. with an electric choke. The carb. is not running smooth and will cause the Bronco let everyone know that it has arrived after the engine is turned off. Thanks of any input.

 

[Gavin Allan]

Might be carbon build-up in the combustion chambers causing after-run. Run some combustion chamber cleaner to help clean up the carbon. You can also slowly pour a large glass of water down the intake while rev'ing the engine (find someone who has done this and knows what they are doing) to clean out the carbon buildup.



Some carbs have a solenoid that allows the throttle to snap shut when the ignition is turned off to prevent the after-run. Does yours?



Probably best to start with a good overall tune-up, making sure that the ignition system (plugs, wires, cap, rotor, points/condensor, dwell, timing, if equiped) are in good shape. Then clean carburetor, replace filters, check for vacuum leaks, cracked vacuum lines, etc., and adjust the carburetor per the shop manual.



Good luck!



I sure do miss adjusting carburetors and changing points (at times)!

 

[Tom Schindler]

Gavin,



I know exactly what you are talking about with the glass of water. It is amazing when you see all the black soot come out of the tailpipe.





Tom

 

[Michael Martin]

Many different things can help the "running on" after the ignition is turned off. Octane, tuning, all kind of things. If the Bronc is an automatic, she could simply turn the ignition off when it's in drive and it shouldn't rattle as much!

 

[kil roy]

i have had many broncos over the years from straight 6

to 351s so without knowing what engine is in it

and if it hasnt been tuned up in a while i would

start with 1/3 of a can of seafoam in the combustion

chamber ala the the write up in the projects section before messing

with the carb.



then assuming its an original 74 engine i would do points and condenser first

( these are only good for 5k to 8k depending on brand) and

see how it runs. if it improves then do plugs, wires, cap, rotor

and set the timing add a can of seafoam in the tank and see how it runs.



only after that would i start messing with carb settings because if you dont know

what you are doing it can get bad pretty quick.

 

[Rodger Tellefson]

Rich, All I know about the engine is that it is a small block V8. Whether it is original or not, I do not know; but looks like it could be.

 

[Michael Cacioppo]

The "run on" condition is usually caused by carbon build up or bad timing. Unlike modern engines with solid state ignition, a points equipped car changes timing as the rubbing block on the points wear. The gap on the points should be about 18 thousands of an inch. I believe the initial timing is about 9 degrees BTC.



Although good plugs and wires are important for good engine performance, in my opinion they are not the cause for the "run on" condition.



While you have the timing light out check to see that the vacuum advance and mechanical advance are working. As recommended earlier a good decarbonizing never hurts. Good luck.

 

[Johnny O]

Probably just the carb needs rebuilt and adjusted. If you cannot find anyone local who remembers how to do that :lol:, there is a place called Pony Carburetors that specializes in Mustang and classic Ford carbs and you could mail it to them.

 

[Rodger Tellefson]

Thanks guys.

 

[Aaron Yarbough]

Definitely do the Seafoam to clean any internal carbon build up . It will help the engine run smoother as long as the ignition and carburetor is set correctly. After pouring it directly in the engine, I reccomend adding a can to a full tank of gas to help clean the carb and intake.

 

[Rodger Tellefson]

When I posted this last night it was too late to talk to my daughter, and just got off the phone with her about the info. posted here. She said the engine is a 302 V8 out of a '79 Granada with electronic ignition. When she pulled it out of storage, hasn't been driven for about 3 yrs., she put on new plugs and wires. She is going to run some carb. cleaner through it, and do the the Seafoam treatment which probably won't happen until this weekend.

 

[Aaron Yarbough]

Glad to hear that it has electronic ignition, that makes things a lot better. The Seafoam treatment will definitely help, especially if she does it directly through the intake, and also in the fuel tank.

 

[Lou M]

I have a '71 Baja by Stroppe (see my library). Use this link, www.broncofix.com . These guys are really helpful.



Lou...