surging 5.4

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Nov 10, 2007 | 04:44 PM

codfish

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Joined: Feb 2004

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From: alberta

surging 5.4

Hi everyone
I have a 1999 f-150 with 180000 kms on the motor. Everything was working great until three weeks ago when i had an encounter with a moose.
I hit the moose on the passenger side causing considerable body damange.9200 dollars worth. Truck is now repaired was told only body damage done not mechanical. Now for the promblem, ever since repair i find the truck surging from 100 to 300 rpms roughly every 20 to 30 seconds, which neveer happened before the accident.Was wondering what could possibly have caused this fluctating. any help would be greatly appreciated.

thanks everyone

keep up the great work

Nov 10, 2007 | 11:28 PM

LxMan1

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Joined: Dec 2001

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From: Louisville,Ky.

Possible vacuum leak in the fenderwell, the passenger side fenderwell is where the vacuum canister is located. It could be damaged or the line going to it could be.

Nov 11, 2007 | 03:13 AM

RedDragon777

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Joined: Nov 2007

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From: Mercedes, TX

there are two lines that run behind the throttle body, i have had to replace on twice because of heat damage and again for a cut from something, both times the rpms dropped low then after the replacement everything was normal

Nov 11, 2007 | 08:27 AM

projectSHO89

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Joined: Jan 2004

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From: St Louis

I'd go with Jimmie's suggestion. The impact probably cracked the vacuum reservoir.

You'll likely get a cehck engine light shortly...

Steve

Nov 11, 2007 | 09:11 AM

codfish

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From: alberta

I was wondering vacuum leak to but they hooked the truck up and said there was no vacuum leak.However tuesday the truck is going to a ford dealership for inspecton of the promblem hopefully they will find the promblem. thanks guys for all your suggestions.