My bronco will only start and run with the choke completely open (it is an electric choke) and idk why but it started to do that one morning after sitting all night and it was 30 something degrees outside. The spark plugs look normal. Also I have a vacuum leak somewhere behind the dash that I can’t find and when I turn the ac, defrost, or mix on the engine idles very high.
ethanwilliams125
Vacuum/carb problems 1985 Bronco
- Tags
- 351w 5.8 bronco carburetor idle problems
You can eliminate the dash vacuum leak by finding the vacuum supply line in the engine bay. Look near the vacuum reservoir, probably on the passenger side.
I don’t have anything for you on the choke issue. Seems weird that it’ll only run wide open, especially with your vacuum leak. What carb do you have?
I don’t have anything for you on the choke issue. Seems weird that it’ll only run wide open, especially with your vacuum leak. What carb do you have?
Yo ethanwilliams125,
As packagerjr advised.
Suggest capping HVAC black plastic Vacuum tank on passenger side wheelwell.
![152253]( "152253")
![152254]( "152254")
As packagerjr advised.
Suggest capping HVAC black plastic Vacuum tank on passenger side wheelwell.
Attachments
Did you hear the vac leak before the choke issue or did it all happen at the same time.
You said it has a carb right?
Are you saying it will only run with the choke closed (not allowing air in) or open?
Sent from my iPhone using Tapatalk Pro
You said it has a carb right?
Are you saying it will only run with the choke closed (not allowing air in) or open?
Sent from my iPhone using Tapatalk Pro
Cap all vacuum lines as a first step. My 80 used a vacuum-driven cruise control mechanism under the steering wheel. Maybe your brake booster diaphragm is broken. Eliminate the vacuum leaks before fooling with the carb or you’ll be chasing your tail.
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