[circman]

Hello, I have a 70xr7 with a 351 c. a week ago it would not start and I found that the distributor was extremely loose. Once I got it started it felt like it was running on two cylinders. Once it got to operating temp. It smooth out and I timed it. The problem is that it still runs terrible unitl it reaches operating temp then it smooths out. Does anyone know what I can do to find and fix the issue?
Thank you,

 

[towcat]

Maybe the choke is closed to tight, and it's loading up until warm and the choke opens????????????

 

[circman]

Thank you. I will take a look at the choke. The carb and choke are new on the engine. I think when the folks who were tunning up the vehicle forgot to tighten the hold down bolt to the distributor because it was like two full turns loose and that initially caused the car not to start but when I got it started you really need to keep on the gas to keep it running and it runs rough. If you don't then it just stops running. Any other ideas or suggestions would be much appreciated. I will definitely take a look at the choke. Thank you again.

 

[cj750]

Could be that the choke isn't working at all. What kind of carb, and what kind of choke activation does it have? (such as electric, manual cable, or the original hot air style.)

Also, since you mention the distributor, is it a stock style unit, or aftermarket? If it has vacuum advance, did you time it with the vacuum line disconnected and plugged? Is the vacuum line connected to a ported fitting on the carb, or directly to the manifold? Where did you set the initial timing? Clevelands tend to like a bit more than the stock 6 degrees, IIRC.

Finally, have you ruled out vacuum leaks? The effects tend to be more pronounced on a cold engine. Some of the common aftermarket 4 bbl gaskets cause leaks when used with Ford carbs and/or intake spacers, so if the mechanic that did the install wasn't paying attention, and it sounds as if he may not have been, you could have something like that going on.

 

[circman]

Thank you, it has a 2bbl holly carb. I believe it is the orginal hot air style. The distributor is the orginal stock style. I timed it with the vacuum line off with tape around the end. I set the timing at 1 degree. I have not checked the vacuum lines to the carb or manifold yet. I don't think the choke has been working cause when I would start it before it would run smooth I just kept the pedal down a bit until it started warming up. The engine has been newly rebuilt.

 

[cj750]

Thank you, it has a 2bbl holly carb. I believe it is the orginal hot air style. The distributor is the orginal stock style. I timed it with the vacuum line off with tape around the end. I set the timing at 1 degree. I have not checked the vacuum lines to the carb or manifold yet. I don't think the choke has been working cause when I would start it before it would run smooth I just kept the pedal down a bit until it started warming up. The engine has been newly rebuilt.

One degree? The first thing I'd do is reset the timing to at least the stock 6 degrees BTDC, and 8-10 if it doesn't cause it to ping.
With the original style choke, make sure there is insulation on the hot air pipe from the manifold stove to the choke housing. Also, verify that air can flow freely through the choke air intake pipe, through the heat stove and back out the hot air pipe. The 351C uses a coiled pipe in the manifold to absorb heat, and over the years rust and gunk can collect in there, blocking the necessary airflow.
As for the carb itself, some Holley choke housings use a different thread than OEM Ford on the fitting where the hot air tube attaches. Verify that you have a good airtight connection there. Also, some Holleys come with the passage that draws air through the choke housing into the carb blocked off. Make sure its open, or the system won't work.
Once you've verified all the components are working as intended, it should be a relatively simple matter to adjust the choke actuation by rotating the black thermostatic spring housing. Usually, it doesn't take much.
If all that doesn't solve your problem, post some up close pictures of the carb and choke hook-up. Several sets of eyes looking at it might just catch an issue one person could miss.

 

[circman]

Thank you again, looks like I have some checking to do this weekend. I have not had any time to check things out yet but I really appreciate all your help. I will keep you posted. Thank you again.

 

[circman]

Thanks for all the tips! the problem was that the points were not opening up. Once I reset them, it fired right up and no rough idle. Thanks again!