Greetings

I just thought those of you who own F-150's equipped with the 5.4L engine might like to know about a recent problem that has been developing, and the cure. There have been quite a few cases lately where the trucks will suddenly run rough, have what feels like a miss, have a surging condition, cut out and trip the MIL (check engine light) and give a P1120 code. This problem has been particularly difficult to fix. It is usually traced to the TPS, but replacement fails to fix the problems. As it turns out, the problem is that the computer wiring harness sometimes rubs on the A/C accumulator. The fix has been to simply pull the harness away from the accumulator, and tie it so that it stays that way. Just thought you might want to know.
Take care,
-Chris

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'95 Eddie Bauer F-150 SC & '64 Falcon/Ranchero
-------------------------------------
Are you A.S.E. Certified ? If so, ask me about
iATN...the best tool you'll ever have ! ! And it's
free

 

Chris,

Thanks for the heads up. I'm going to check the harness tomorrow morning.

I had the exact problem you're describing and took it in. It's missing again. Comes and goes, actually.

Dennis

 

Ahhhh, the value of this site just keeps increasing. Thanks for the tip.

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'99 F150 SC, 4x2, Oxford white, flareside, 5.4, 3.55 rearend,
bodyside mouldings, Snugtop hard tonneau, K&N dropin and airbox mod. Duraliner drop-in (gave up on the Penda Nascar).
Future mods: 2/4 lowering, bra and some Roush stuff. Also want Gibson Supertruck

 

Great info. Im sure alot of the 5.4l owners need to be aware of this.

 

CHRIS!!! YOU ARE THE MAN!!!!

Totally forgot to check the wiring this morning, so at my first stop, all I could do was jiggle the harness, thinking "this is stupid, but, what the hell..."

You could have knocked me over with a feather... I started up the engine and no miss. Perfectly smooth.

When the engine cools off, I'll figure out a way to tie it back away from the accumulator tank. I have no idea why this works. It makes little if any sense to me, BUT it works!

I owe ya, buddy!

 

Thanks for the info PKRWUD!

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'99 F150 XLT SC,Styleside
4X4, ORP, 5.4L, 3.73s, Line-X, and Borla dual tip side exit.

 

i'm cheaking tonight
thanx

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99 XLT SC 4x4 STYLESIDE ORP 5.4,AUTO & 3.73 POSI
MED. TOREADOR RED
EXTANG TONEAU,BED MAT,
K&N FILTER & WOOD DASH KIT

 

Great info...is this for all year models?

I JUST picked up my 2000 last night...
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2000 F-150 XLT, 4x2, 5.4L Supercab, Black with silver two-tone, 3.55, towing package, sliding rear window, keyless entry, dark graphite interior, in dash CD, bedliner, K & N air filter, cabin filtration system

155 miles on it now and love it!

[This message has been edited by Dustoff (edited 10-22-1999).]

 

Dennis- Glad to help

Dustoff- I haven't heard of any cases yet with the 2000 models, but that doesn't mean they are safe from it. Just remember what I said above in case you start to have a similar problem. Put it in your "just in case" file.

Take care,
-Chris

------------------
'95 Eddie Bauer F-150 SC & '64 Falcon/Ranchero
-------------------------------------
Are you A.S.E. Certified ? If so, ask me about
iATN...the best tool you'll ever have ! ! And it's
free

 

Damn! You just gotta love this site!
Thanks PKRWUD, I'm looking at a '00 5.4
to pull my boat.

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'99 WHITE F150 XLT FlareSide SC 4.2 Auto 3.55, Superchip,
Black Westin Nerfs, White Prime Design BugShield,
White Vtech Taillight Covers, White Vtech Sidewinders,
'99 White Styleside Body Side Molding, K&N Air Filter
LOTTA SHOW and SOME GO
My am E, Fl *** Member of ??? Ford Group

 

I have a 99 Navigator with the 32v 5.4l engine with about 15,000 miles on it. Twice in recent months I have experienced a hesitation midway through acceleration from a stopped position. The engine seems to die for a second and then keeps on truckin like it never had the problem.

I have not yet had the problem checked out since it occurs rarely and I am waiting for my next oil change. Other than this, I haven't had any problems at all.

Does this sound like the same problem? One way or another I am going to take a copy of this thread to my dealer so they can help other F150 owners if they are unaware of this fix.

 

ml- It's possible, but without seeing your vehicle in person, it's really hard to tell. You might want to try what I suggested and see if the problem goes away. If it continues after that, you should go to your local dealership and have them take a look at it. Good luck.
Take care,
-Chris

------------------
'95 Eddie Bauer F-150 SC & '64 Falcon/Ranchero
-------------------------------------
Are you A.S.E. Certified ? If so, ask me about
iATN...the best tool you'll ever have ! ! And it's
free

 

Well, it's been 3 days since pkrwud's fix and let me tell you... It's like I'm driving a brand new truck. Mind you, it's a '99 that just had it's 5,000 mile service.

This truck has barely been getting 12 mpg and the last time the missing got really bad, about 2 or 3 weeks before the computer coded, mpg would drop to the 10 to 11 mpg range.

Performance has been better than the 4.6L in the '97, but not significantly better, in my opinion. In fact, I didn't think it was worth the 2 to 3 mpg hit in mileage.

Well, since the miss has been fixed (thanks to Chris), I've been burning rubber all over town. LOL. I filled up on Saturday and took two drives this weekend. Normally, the gas guage would have dropped down to 3/4 tank from full on these drives. However, last night, I noticed that it was down to just under 7/8 tank.

I'll fill it up at the end of the week and report back. I'm certain the mpg will go up, although I'm having a lot of fun putting the "pedal to the metal" so, it may not have improved all THAT much.

If you got the 5.4L in your truck and there's a slight to bad miss, jiggle that harness and see if it fixes the problem. I'm still scratching my head over this one, but know what? I got a BIG smile on my face!

 

Where exactly under the hood is the A/C accumulator? I want to check this on my truck, but I need to know what I'm looking for. Thanks.


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1999 Lariat SuperCab Flareside, Amazon Green with Silver trim, 5.4L, 4x2, 4 wheel disc/ABS, 3.55 limited slip, towing package, fog lamps, sliding rear window, captains chairs, keyless entry with alarm, spray-on bed liner, bug guard, and K&N. http://www.csc.calpoly.edu/~bfriesen/truck.html

 

Hey folks!!!

Just the other day I was pondering the thought that my truck isn't as quick/fast as it once was. I thought I had just gotten used to the power and the 11MPG that I can't seem to improve on.

So, from what I understand and correct me if I'm wrong, this wiring harness my be causing a lack of power and poor mileage as Dennis stated.

I'm waiting for a confirmation on my 5K sevice and would like to have my facts straight if I infact have this problem.

(WOW, just think, MPG over 11)

Thanks PKRWUD!!!

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99 4x4 XLT supercab 5.4L Flareside, Deep Wedgewood Blue/Med. Graphite w/Captain Chairs, Pioneer DEP-4000, Tint, K&N, Bedliner, 3" Catback w/3 Chamber Flowmaster, 285/75/16 BFG A/T on American Racing Python wheels

'00 Expedition, Silver w/Dark graphite, 5.4l and some other stuff. All in all she'll stay stock.