1990 Ford Bronco

WESLEYM433

MEMBER
1990 FORD BRONCO

1990 Ford Bronco 6 cyl Two Wheel Drive 72000 miles

I have a 1990 bronco II 2.9 v6 fuel injected. Runs a little rough at idle. Noticed when I killed the motor sometimes smelt gas. On the area where the vacuum fittings are one of the caps or plugs was worn through. A little gas is coming through when the motor is of and there is no suction. Farther checking found it is probably getting to the brake booster. I replaced the booster and that didnt fix the rough idle cmpletely but runs a lot better.
What I am looking to find out is why is there fuel running to my power booster when it is now running.I isnt much but it shoudnt be getting into my vacuum lines at all. Maybe I am a little clearer after this edit.
What the problem?

6 Replies

MERLIN2021

MECHANIC
17,250 POSTS

You may have a vacuum leak, get a can of spray gumout, spray the vac lines and maniflod area, when the idle changes, youve found the leak! You want the engine running and spray on the outside but do direct the stream onto the hoses, if it is a vacuum leak, the engine idle will change speed, then you have detected a leak, repair the vacuum leak and see how it runs! If that doesnt do it, you may need a new idle air control valve, it's bolted to the throttle-body
If you have a known vacuum leak, fix it. If your check engine light is on, let me know and I will show you how to read Ford trouble codes.