vacum question

[beatbackford]

I have a 91 explorer qith the 4.0 v6. It has been getting approx 8-10 mpg latley, which is a lot less then usual. I can almost watch the gas gauge move. When u hit the brakes the gauge seems to drop, and it doesnt come back up. Other then a small o-ring leak on a couple injectors, there doesnt seem to be a leak. The only thing wrong i can see is some cracks in the end of the vacum line at the brake booster. Would that cause a leak when i apply the brakes?

 

[arco777]

You can check for a vacuum leak by spraying carb cleaner at suspected leak areas while idling. If there is a leak, the vacuum will suck in the cleaner and the idle speed will momentarily change.

I would suggest running full KOEO and KOER tests in case something like a bad sensor is causing your engine to run rich.

 

[huntman58]

You can check for a vacuum leak by spraying carb cleaner at suspected leak areas while idling. If there is a leak, the vacuum will suck in the cleaner and the idle speed will momentarily change.

I would suggest running full KOEO and KOER tests in case something like a bad sensor is causing your engine to run rich.

I agree