99 F150 Fuel System Problem

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Sep 6, 2007 | 09:56 PM

162bruins

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99 F150 Fuel System Problem

My 5.4 yearly is driven about 7,000 miles of which it currently has 80,000 miles.
For the past 3 years, each year I get a sputtering or jerkiness at all speeds. For the past 2 years I would simply replace the fuel filter and the problem went away. This year the same thing again, and I replaced the fuel filter but the problem hasn't gone away. I continue to get the sputtering and jerkiness. No warning lights come on ... the truck runs 100% otherwise. Any thoughts would be appreciated... thanks.

Sep 6, 2007 | 11:51 PM

loony2000

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Fuel Pressure Regulator? Or maybe the fuel pump itself... dunno.

Sep 7, 2007 | 12:04 AM

LxMan1

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From: Louisville,Ky.

Sounds more like a coil on the way out. Scan for codes, one may be stored, even though the light isn't on.

Sep 7, 2007 | 07:30 AM

162bruins

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It wouldn't happen to be a map sensor would it?

Sep 7, 2007 | 10:35 AM

projectSHO89

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From: St Louis

Quote:

Originally Posted by 162bruins

It wouldn't happen to be a map sensor would it?

Since your engine doesn't have a MAP sensor, it's pretty unlikely.

It's most likely weak fuel delivery or a low grade misfire.

There are other possibilities, however, I'd check the odds-on favorites first.

Steve

Sep 7, 2007 | 10:45 AM

blue beast

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From: sunny fla sometimes windy

Do you mean you only drive it 7k miles a year? When you park it do you leave it with a full tank? If not condensation is building in that empty space and then it ends up in the gas, leading to the water clogging up all the small restrictions(injectors,jets,fuel filter) water has a high surface tension so when a bunch of molecules stick together, It blocks up the passages. That is why changing the fuel filter let it run good for a while until it got blockaded by water. Grab a few bottles of dedicated gas line dryer 1 bottle treats 10 gals. but I would double or triple up on the dosage. Mix the two types to get the best results one has methanol and the other has isopropyl alcohol. I guarantee that will cure it and try leaving it with a full fuel tank and a bottle of dryer every couple months will keep it running good!!!!

Sep 7, 2007 | 04:42 PM

162bruins

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Well I didn't have the time to work on it and found out that it was another problem altogether. Turns out the two sparkplugs at the back of motor were both rusted from water. Somehow water got into the wiring harness and subsequently arced out the two plugs. I just changed these plugs not 10,000 miles ago. No idea how they became wet. Thanks for all the help guys.