Will not accelerate

[Wolfpac]

I have an 07 with 5.4l, I have replaced the throttle body and the spark plugs, but the truck will not accelerate past 40 mph and will only rev up to 3000. It keeps throwing codes that different ignition coils are bad? I plan on replacing all 8 of the coils, but could something else be causing this issue? Any help is greatly appreciated!

 

[Bedrck47]

Welcome to the Forum

 

[Bedrck47]

How many miles on the expy?

When you replaced the plugs did you also replace the boots and wires?

 

[Wolfpac]

It has 120k on it, it has no wires only individual ignition coils.

 

[Bedrck47]

correct me if I am wrong but what connects the coil to the plug

 

[Wolfpac]

They are single coils mounted directly on the spark plug. There is a wire that comes from the computer directly

 

[Bedrck47]

true but isn't there a rubber boot that goes over the spark plug

 

[Wolfpac]

Yes there is a rubber boot, I just bought the coils and boots... I am not sure if that is going to fix it. I was looking to see if I missed anything.

 

[Bedrck47]

and inside of the rubber boot is a coil spring (wire) that connects the coil to the plug. That is what I was referring to when I asked if you changed boots and wires as you only stated that you changed plugs in your original post

 

[Wolfpac]

I have not changed those yet, I am hoping they are part of the coils that I bought.

 

[Bedrck47]

most likely the new coils will have boots and wires included

The reason I asked if you changed boots and wires was I once had a misfire and I only changed the plug and I still was getting a misfire I pulled the plug again and noticed there was a pin hole burn in the rubber boot that was causing the misfire.

coils normally don't just go bad but plugs and boots should be changed since the boot is inside of the plug well and subject to some intense heat.

what are the codes that you have been getting

 

[Wolfpac]

The codes are for primary ignition coil for cylinders 4 & 5... I changed cylinder 3 when I did the plugs because the boot was torn. In hindsight I should have just changed them all.

 

[Bedrck47]

do you know the code numbers

 

[Wolfpac]

The codes are P0354 and P0355

 

[1955moose]

Wolfie your codes are number 4 and 5 cylinders. Those are the spark plugs/ boots/ coils you want to concentrate on for now. You might have other issues but this is where you start.


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[docraymund]

Bring the truck to an exhaust shop and have them check if the cats are clogged.

 

[Bedrck47]

Bring the truck to an exhaust shop and have them check if the cats are clogged.

What would clogged cats have to do with the primary side of the ignition coils

Please enlighten me on this one

I am willing to learn

 

[1955moose]

I'd like to know that one myself. Loss of power maybe, but Exaust wouldn't trip those codes! If you do have any Exaust leaks, by all means get those fixed. You didn't mention that in your text.


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