97 4.6 Weak engine start

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97 4.6 Weak engine start

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Ford Forum >> Ford Trucks, Ford Vans & Ford SUV's >> Ford F-150 >> 97 4.6 Weak engine start

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97 4.6 Weak engine start - 1/16/2006 2:20:15 PM

jcwilliamsjr

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Looking for some assistance in where to start. I have a 97 F150 with a 4.6 at 116K and have some problems starting it after it has sat for overnight. I do not have problems with the starter motor. It seems like the engine has a week spark, not enough fuel pressure or an air fuel mix that is off or something like this causing it to be hard to start. No engine fault codes as of yet so I am trying to see if anyone else has seen this problem. I bought the truck used and know that a recent tune-up was completed.

Post #: 1

RE: 97 4.6 Weak engine start - 1/16/2006 6:08:36 PM

Bullitt94

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Does the engine just have to turn over a long time before it starts, or is it turning over hard, ect.?

(in reply to jcwilliamsjr)

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RE: 97 4.6 Weak engine start - 1/16/2006 10:15:34 PM

bosshoss

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Hello.
Next time you try to start your truck, do this. With everything turned off windows up listen real hard when you turn the key to the run position only. DONT START. Can you hear the fuel pump whine then stop?

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Dave P.

(in reply to Bullitt94)

Post #: 3

RE: 97 4.6 Weak engine start - 1/17/2006 11:48:10 AM

Bullitt94

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You're thinking along the same line I was...

If you do hear the fuel pump whine and stop, that's normal. If it doesn't, that could be your problem.

If you hear the fuel pump, try turning the key off and back to the "run" position and let the fuel pump whine again. Do this a couple times and try to start it. If it starts easy, then it could be the valve in your fuel line that stops the fuel from running back into your tank when the engine is off has gone bad.

_____________________________

1994 Ford Mustang GT
1990 Ford F-150
2001 Lincoln LS V8
1970 Ford Bronco
2006 Harley-Davidson Sportster Custom
1990 Ford Bronco II

If you don''t already own a Ford (or Ford owned product), get one.

(in reply to bosshoss)

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RE: 97 4.6 Weak engine start - 1/17/2006 10:02:07 PM

hockeyhitman69

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there is a check valve in the tanks which cause them to hold there pressure ,get your fuel pressure tested and then shut the engine off and see if drops out quickly it should hold the pressure.....

(in reply to Bullitt94)

Post #: 5

RE: 97 4.6 Weak engine start - 1/18/2006 4:43:43 PM

jcwilliamsjr

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Joined: 9/28/2005
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It is not the starter as the problem. The engine starts to crank up right away then will not continue to run. If it is cold in the single didgets to 30°F the engine starts fine. It only seems to do this while in the garage overnight at approx 55°F - 65°F. I did read a TSB about hard starts with Bi fuels is there a fix for this problem?

(in reply to Bullitt94)

Post #: 6

RE: 97 4.6 Weak engine start - 1/18/2006 4:55:50 PM

jcwilliamsjr

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Joined: 9/28/2005
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Fuel pressure seems ok in pretty much all temps. The engine trys to start almost right-a-way however will not contiue to run. This only seems to have issues in a certain temp range between 45°F to 60°F. In colder or warmer conditions I do not have this problem. I do see a TSB about running Bi-fuels.

(in reply to bosshoss)

Post #: 7