I finaly got my bronco back .(Long story) Its a 85 with a 351 4-barrel gas guzzler 391k miles. Any ways its got some carb issues. Runs VERY rich (gettin 4-7 mpg on 265's) how do you adjust the air-fuel mixture on these? It is hard to start and when it does it puffs black smoke and sounds like its only runnin on a couple of cylinders, but it clears up and runs pretty good but it idles real high (15 to 1700). Do you guys think this is mostly carb related?

 

Should be mixture screws at the base of the primaries. Rule of thumb that I've always used is lean them out until it starts to cut out, then back them off a 1/2 turn.

Is the idle set screw backed all the way out when it's idling that high?

 

I dont no, didnt have time today (just brought her home today) and it started getting dark. I had a brain fart earlier and thought maybe the choke was stuck. Would explain the high idle and some of the richness. I plan on working on it tommorow suppose to be like 70 degrees. I hope anyways.

 

Hey Josh you still in trouble with dad ?

 

shhhh


This isnt josh its his friend who uses his acount....

 

Hahahahaaa....that's pretty good. Don't worry kid, you can't stay grounded forever.

 

Well today I went out there to see what I'm up against and right off the bat found a leaking gas line. Some one tightend the clamp to hard on it and it was leaking pretty bad. I Also partly fixed the idle issue. The throttle stop bolt wasn't back far enough and wouldnt let the throttle close. So now it only idles around 900 rpm which is alright cuz when I put it in gear it drops to about 500. Tommorow I am going to get a new hose and see what it still does after that.

P.S. do any of you no what axle code H6 is? I cant find one on the web that has that code. Can only find H4 and H9....

 

Sounds like the mixture screws are fine, but I'll bet you've got a small vacuum leak.

H6 axle code is Ford 9" 3.50:1 Limited slip.

 

Ya cookie I'm almost positive I have a vac leak cuz the cruise control doesnt work. Thats probably next on the list of things to fix. I dont think the mixture is fine though because I remember my uncle telling me that he messed with it trying to get better gas mileage (but he doesnt know a thing about carbs). But I didnt See anything that resembled a mixture screw, (I'm used to working with dirtbike carbs though). What side would they be on? Oh and what do you think my odds are to replacing the spark plugs without breaking them. Its been a VERY long time since they have been changed.

 

Well I figure I'll give yall an update now. I found the primary mixture screw and it was WAY to rich, it was like 4 or 5 turns before it even started to sputter. So I got that adjusted right (atleast I think I havent taking to for a test drive yet). But I still cant seem to get the stinkin idle down. Is there and idle screw on it any were?

 

There should be one on the throttle linkage.

 

I'm with cookie - sounds like there's a vacuum leak somewhere as well. I've had good luck with spraying a little carb cleaner on the surrounding lines while it's running. If it idles up, there's your leak. And of course, somewhere along the way one may have popped off or completely disappeared...