"hesitation" F150 5.0L Auto - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

ziggystar · 03-15-2005, 08:38

Hi there from Vancouver, BC
New to this site. Posting question for my brother who has a 1995, F150, 4WD, Auto, 131,000 km. Truck has been parked for a few months (?6) in the garage. Truck is inconsistently hesitating. Here's what happens: Driving in country and city, engine light goes on followed a few seconds later by a loss of acceleration even though still pressing on gas, then a few clunks (sounds like coming from front not far from our feet a few times and I think I heard a clunk in the mid to back range once, too) and then power is then restored and truck accelerates. This has happened at the beginning of acceleration (starting at a green light) and also just driving along without stops (country road 70-80 Km/h). This was still happening even after being on the road most of the day.
Any ideas anyone? Greatly appreciated and Thank you!

Butchart · 03-18-2005, 14:30

Hi, you might have a clogged fuel filter or a faulty fuel pump relay. The clunking sound you describe is like it would do if the motor was not getting enough fuel causing backlash in the drive line. I am only telling you this from my own experience with my 88 F-150, has 188k on it and the motor runs now like it was brand new.

ziggystar · 03-21-2005, 20:48

Thank you very much for the information! I will pass this along to my bro.
Regards!

ziggystar · 04-12-2005, 07:02

Hi Butchart,
My brother has since taken the truck for a few drives on full tanks and with STP and the problem seems to have gone away. He figures it was probably junk coming up out of the tank and doing as you said, clogging the fuel filter. I have advised him of getting a new fuel filter, too.
Thank you so much for your help.

Butchart · 04-12-2005, 21:08

Thanks for posting your results. Lot of people end up getting their problems fixed but never answer back on here so we never know how they made out. Anyway another idea came to me, (actually it was on the bottom of the posts) you might want to try some injector cleaner if the problem comes back. Sitting for a long period may have clogged up the fuel injectors, condensation in the tank creating some moisture with the fuel. One guy had a similiar problem with his vehicle bucking, hesitating and loss of power and found out it was a plug wire, replaced it and vehicle ran fine after that. My problem was the fuel pump relay, cost me about $25 for a new one and truck runs excellent now.