How to diagnose why F150 runs badly?

40

Asked by Mar 31, 2015 at 09:36 PM about the 2001 Ford F-150 XL Extended Cab 4WD LB

Question type: Maintenance & Repair

I know nothing about Ford F150's so here I am, asking for help in how to determine why my daughter's 2001 F-150 4wd extended cab 5.4 liter engine starts easily but will not produce enough power to move. The truck ran fine and then suddenly deteriorated terribly. A car repair center found nothing in the computer error codes to indicate any sort of error. My daughter doesn't have a lot of money so it is going to be up to me to determine if the truck is worth fixing or not. If the engine timing chain has skipped a tooth then that's the end of it. However, if it is a coil or something else that I could address, that is another matter altogether. The problem is economics and information. I need help in figuring out how to figure out what's wrong and I need to do it without spending a lot of cash. Suggestions on how I should proceed?

8 Answers

40

Have you changed the fuel filter?

2 out of 2 people think this is helpful.
61,115

Agree,with bidD, check the fuel filter,and then check the fuel pump.

61,115

Undo fuel filter,cut key on ,if you see good fuel,then pump is good,if not ,then change fuel pump.

40

Astoundingly quick response! Thank you very much. Why be suspicious of the fuel filter? Where is it?

2 out of 2 people think this is helpful.
61,115

Should be under truck driver side,on frame,sound,s like it is starving for fuel.

1 out of 1 people think this is helpful.
40

Thank you. I'll crawl under the thing this weekend and verify whether or not fuel is coming out of the filter. One other puzzling symptom: when the gas pedal is depressed the engine runs a little faster but misses and does so without power and, this seems strange to me, the overdrive light on the gear shift blinks on and off.

40

Arg. It takes a special tool to disconnect the fuel filter. As an alternative, I have a can of starter fluid. If the problem is fuel starvation then would it be possible to spray starter fluid into the truck's air intake to confirm?

40

Symptoms update: Truck starts easily and idles. While in Park pressing the gas pedal results in the truck engine smoothly turning over faster, easily getting to the top of its safe RPM range which would argue against either timing or an electrical problem. While the truck is running, the Overdrive Off light is blinking on the gear shift. Pressing the button at the end of the gear shift has no effect. Putting the truck in gear results in the truck transitioning from an easy idle to running rough and drastically loosing power, to the point where it does not develop enough power to move it on flat pavement. Spraying starter fluid into the air intake results in the truck running much better, developing enough power to move. The fuel filter is not blocked up. Gas flows through it well, a steady stream that is maybe 1/8 thick and flow is strong. I looked at the gas that came out of the fuel filter and it looks clear, containing no water bubbles or other debris. Looking at the gas gauge indicates that the tank is very low but not empty, a little space between the E line and the needle. Just because I have a gas can available I will throw another 4 gallons into the truck although given the unrestricted flow of fuel out of the filter it would be surprising if that made a difference. I am once again hopeful that someone has good suggestions on what I should try next.

1 out of 1 people think this is helpful.

Your Answer

Add photo

Related Questions

  • 5.4 Triton, need help badly 16 answers

    I have a 04 fx4 5.4, I got it with the tick but very subtle, after a while it starting getting worse and worse until the motor started shaking pretty bad and stalled twice all while driving one ni...

    2004 Ford F-150 FX4 Ext. Cab 4WD

    -

    Maintenance & Repair

  • 1986 Ford F150 Carburator 8 answers

    I have a 86 Ford 6 cylinder with a 2 barrel carburator which needs replacing. The local Ford dealer says they are unavailable. Is there an after market solution? It seems that most are one barrel ca...

    1986 Ford F-150

    -

    Maintenance & Repair

  • 1987 ford f150 wont fire at all and already changed coil what do i do? 6 answers

    firing problem with 1987 ford f150 changed coil already and still not starting.

    1987 Ford F-150 XL Extended Cab LB

    -

    Maintenance & Repair

  • misfire on acceleration. 3 answers

    i have a 1990 f150 larait 300 6cyl. i recently did a tune up and got cyl 4 and 2 reversed on the cap.. i feel dumb but now it runs alright at idle. took it for a test drive and i made it about a block...

    1990 Ford F-150 XLT Lariat 4WD LB

    -

    Maintenance & Repair

  • is a 4.9L straight 6 a strong motor in the f150? 49 answers

    1991 Ford F-150

    -

    General

F-150

Looking for a Used F-150 in your area?

CarGurus has 212,656 nationwide F-150 listings starting at $1,000.

ZIP:

Search Ford F-150 Questions

Ford F-150 Experts

#1 OJ
OJ
Reputation 6,880
#2 dandyoun
dandyoun
Reputation 4,180
#3 tennisshoes
tennisshoes
Reputation 2,510
View All

Related Models For Sale

Used Chevrolet Silverado 1500
2,297 Great Deals out of 156,238 listings starting at $1,395
Used GMC Sierra 1500
928 Great Deals out of 62,271 listings starting at $1,395
Used Dodge Ram 1500
537 Great Deals out of 12,998 listings starting at $2,199
Used Ford F-250 Super Duty
426 Great Deals out of 45,049 listings starting at $2,000
Used Toyota Tundra
626 Great Deals out of 30,696 listings starting at $2,637
Used Toyota Tacoma
627 Great Deals out of 35,082 listings starting at $2,155
Used Ford Mustang
399 Great Deals out of 44,403 listings starting at $1,000
Used Ford Explorer
1,000 Great Deals out of 73,800 listings starting at $750
Used Chevrolet Tahoe
809 Great Deals out of 28,674 listings starting at $1,500
Used Ford Ranger
209 Great Deals out of 6,719 listings starting at $1,450
Used Jeep Wrangler
442 Great Deals out of 19,188 listings starting at $2,994

Used Cars For Sale

2017 Ford F-150 For Sale
3 Great Deals out of 100,942 listings starting at $18,940
2016 Ford F-150 For Sale
196 Great Deals out of 43,534 listings starting at $16,995
2015 Ford F-150 For Sale
200 Great Deals out of 7,337 listings starting at $17,480
2014 Ford F-150 For Sale
465 Great Deals out of 11,869 listings starting at $10,700