My 93 f150 with a 5.0 engine runs good until I start climbing hills.It slows down to 30-40 mph and I have to shift to 4th or 3rd. It has 214000 miles doesn't burn oil so the rings are good. I'm thinking valves since everything else is good. I can't even pull a 13' camping trailer. Any thoughts on this.

 

Did it pull that camper okay before?

How old are the plugs, wires, cap and rotor?

Is the Check Engine Light on?

FWIW the 5L is not known to be a powerhouse engine.

 

All electrical ignition parts are new,no check engine light on. Never pulled the trailer,I tried and got 35 miles before overheating due to bad radiator cap but during that 35 miles it had very little power pulling up hill. I had the timing checked and it still pings and shakes when pulling up a hill with heavy throttle. I'm with you on the 5.0 not being a powerhouse but this is useless. Otherwise it runs great with 16 mph on a easy ride. In town I'm getting 13.

 

Tire size? height and width

Gear ratio? Check the driver side door jamb sticker for the axle code.

Was the SPOUT plug removed when setting the base timing?

Any other modifications?

 

Stock tires 235-75, axle code 19 , don't know about spout plug. My mechanic did the tune up but it was the same thing before and after. It has a 5 speed standard trans.

 

Does it have a tachometer?

If the timing is indeed correct, and their aren't any codes, I would check the fuel pressure.

Have you changed the fuel filter recently?

 

No tach,filter changed six months ago. Fuel press. Interesting,I'll have it checked.

 

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I would have to ask, how big or what's the grade and length of the hill you're trying to get up in 5th gear? Then is the engine speed slowing down or just the truck? Are you slipping the clutch? I mean think about it, gear 5 or OD, weren't meant to climb hills.

 

I was just driving on the cost road in Oregon and was passed by a Toyota pickup at 45 mph. I started out at 60 then shifted to 4th .I had my mechanic look at it today and he found that the catalytic converters were bad. He removed them and replaced the muffler. It seems to run a lot better. I am going to test ride it tomorrow. They were 40% plugged up. No wonder it was running bad.Hope this fixes it.

 

Have you checked the MAP sensor?

 

What's a MAP sensor? I test road it today up some 5% grades on the freeway and still losing power. At bottom of hill 70 mph had to shift to 4th to maintain 55 mph at the top,engine shaking and missing. Flat out on surface streets good power.Timing was checked and was good. Stumped.

 

Your truck should have the MAF (Mass AIR Flow) sensor at the intake duct.

 

It's going back into the shop next week for AC leak and the shop owner said he will check things again. I want to put a cab over camper on it but it has to run better first. I'm looking for one for a 1/2 ton p/u not a big one. 1200lbs max.

 

No not on a '93.