Our 1994 F150 Supercab 4x4 isn't running right. When put in drive and given some gas it starts to go and then bogs down so much it's undriveable. It does this in 1st, 2nd, and D. Reverse seems to be ok. Also, when driving and taking my foot off of the gas pedal it slows down too much, almost like it's dragging something.

I jacked up the rear end and am able to turn the wheels by hand, it doesn't sound like the brake shoes are rubbing.

Any help would be appreciated.

Thanks, Bill

 

I'd start by checking for vacuum leaks & change the fuel filter...then clean the throttle body and AIC and MAF

any codes present?

 

Thanks for your reply. I was thinking vacuum leak also. Any tips for checking other than looking for loose vacuum lines?

No, there aren't any error codes.

 

you can take carb cleaner & spray down lines with it running...if it picks up RPM in a area ...pretty good indication of a leak where the RPMs change. ( just stay away from the exhaust)

you can also hook up a vacuum gauge in the plumbing of the vacuum system.

this is from another site but show some very good info.
http://www.therangerstation.com/Maga...acuumLeaks.htm

key point to check is the PCV line /elbow on the rear of the throttle body is a known weak spot...also back behind the battery

 

Cats?

Or maybe check your air cleaner tube where it goes from the fender to the air box, I've heard of some choking at that point before. And I don't think it throws a code either.