Running rough when warmed up.

[gladrich]

I started having this problem after Bronco sat all winter in the barn. It runs great until it gets warmed up but then it starts sputter and runs pretty rough. I'm not sure where to start troubleshooting. It's got the original 302 and I put a holley 4 barrel and edlebrock intake on it. Appreciate any guidance.

Thanks.

 

[tasker]

points been checked lately?

 

[gladrich]

I Put electronic ignition on a few years ago.

 

[tasker]

Fuel filter? vapor locking?

 

[gladrich]

filter looks ok. only about 1 year old.
thanks

 

[pipeline010]

you mentioning it runs better before warming would tip me that it's potentially running rich. When colder it likes less O2 and more gas. As it warms it doesn't like your balance anymore. I'd be checking the filters, carburetor float levels and maybe trying some other jets.

 

[75MIKE]

Coil or ignition module.

 

[Rustytruck]

I would ohm check the mag pickup. I would check the temperature at each exhaust port with an infrared gun or a spritz of water from a spray bottle and watch the sizzle. I would check for vacuum leaks everywhere, a cracked or loose line or cap. I would pull the idle screws out and spray carb cleaner through them and any little vent spots on top of the carb. I would hook up a vacuum gauge and watch the needle see if the needle is steady. look up a vacuum diagnoses chart and compare the needle readings.

 

[Eoth]

Pretty basic but are you sure your choke is not stuck on? As already suggested, once you verify that it is working properly, then you could have a fuel delivery issue (clogged jet or idle circuit). Next in line I would look for a vacuum leak. Further out there (happened to me) is ignition coil. Mine lost fluid over time and the engine would run like crap because the coil was overheating.

 

[gladrich]

Thanks for all the replies. Really appreciate it.

 

[gladrich]

Looks like the winner is.......Tasker! It looks like it was the fuel filter! I have the 1973 fuel tank. Wonder if it is deteriorating or if I just got some bad gas.



Thanks all.

 

[jckkys]

The choke is super basic, and should have been the first thing to check. Is the engine making black smoke when at operating temperature? A stuck choke makes the A/F mixture very rich. If the the engine is warmed up and the choke plate isn't fully open, the automatic choke is stuck.

 

[73azbronco]

Knowing the vacuum is always a basic diagnosing help.

 

[tasker]

GLAD it was something simple! now go drive it!!