Howdy everyone,

I have a 1999 F150 Reg Cab 5sp man...starts with no problem and generally runs well. The problem i have is when you shift a little soon and bog the engine down a little or when you step on the gas to pass, then engine seems to stutter. It feels like its cutting out. I've had it hooked up to the machine at my father's mechanic and it has never had the CEL on. Nothing can be found that is wrong with it (at least with the diagnostic machine). What could possibly be an explanation. The truck has stock fuel filter. Tune up at 105.000 miles (124000 now). I have noticed a slight drop in mpg over the last couple of months, so thats another question. I hope you guys have an idea of what i can check on. I'm sure you get this type of question a lot. What should i start to look at?

Thanks.

aggiejrc

 

how soon is a little too soon. For instance if you are shifting form first to second at 8 mph and it stumbles a little thats normal. For normal driving 10-15 would be a desired shift point, While 3rd should be ok with 25-30, fourth 45- 55. and over drive 55+.


by stock fuel filter do you mean factory never been changed, if so change it.

 

fuel filter never has been changed, to my knowledge, not since i've owned it. the problem with the stuttering usually occurs after i shift to third gear and need to accelerate quickly. does the same in fourth/od..i don't usually bog the engine down, usually shift at 15-26-40 for second through fourth. what other things could i replace as well. perhaps a tune-up again?

 

I'd say change that nasty fuel filter, My GF's car had 112k before it started to get clogged, and If i would have know I would have changed it before It started giving her problems.

 

Interesting how many different driving habits there are. My shift points are...

2 - 10mph
3 - 20mph
4 - 35mph
5 - 40-50mph depending on terrain

It probably seems real low to most people but it doesnt bog my engine down and I get perfect acceleration.

 

When I'm in town I'm in 5th at 30. I even skip shift it. The low end torque on a 4.2 is amazing.

 

Yeah, ive done that too.

 

Dude im having the same exact problem. I replaced plugs and wires and the son of a bitch is still doing it. Let me know if you have any luck with the fuel filter.

 

took the truck in, plugs/wires replaced, fuel filter (not the problem), mechanic said it was the coils going bad, had them replaced. no problems now.

 

try replacing the ignition coil

 

the coils on crap on these, will cause all your symtoms.....

 

I had a similar problem , but only when I bought the truck new in 2000 I had to take it back to the dealer ship 3 times before they figured uot that it was a bad plug wire. (they basically called me a liar until i took the manager for a ride) Hope it helps.

2000 4x2 4.2
41,000 (not a daily driver)