Diagnose for me! Please!
Thread Starter
Junior Member
Joined: Jul 2016
Posts: 21
Likes: 0
From: Utah, USA
Diagnose for me! Please!
I was wondering if some of you amazing internet mechanics could diagnose a problem I have on my 06 Mark LT with 3v 5.4 l engine.
I just bought the truck and when I test drove it, I made the stupid mistake of falling in love with the truck before really pushing it and testing it.
So the problem is that the truck is very sluggish. When I floor it, it doesn't accelerate very much. It's worse when I'm on the freeway going up steep hills (I live in Colorado). Often I can't keep up my freeway speed. When I floor it, it revs up and stays revved up for longer than usual because it's barely gaining speed. Cylinder 5 often misfires when I do this.
So here's what I have done so far. None of it has helped the sluggish performance or misfire issue:
Any idea what else it could be???
I just bought the truck and when I test drove it, I made the stupid mistake of falling in love with the truck before really pushing it and testing it.
So the problem is that the truck is very sluggish. When I floor it, it doesn't accelerate very much. It's worse when I'm on the freeway going up steep hills (I live in Colorado). Often I can't keep up my freeway speed. When I floor it, it revs up and stays revved up for longer than usual because it's barely gaining speed. Cylinder 5 often misfires when I do this.
So here's what I have done so far. None of it has helped the sluggish performance or misfire issue:
- Changed all 8 spark plugs
- Changed all 8 coils
- Changed fuel filter
- Changed cylinder 5 injector
- Ran a can of Sea Foam through it
- Always put 87 octane gas in it
- Checked catalytic converters. No back pressure.
Any idea what else it could be???
Last edited by tgb123; Jul 1, 2016 at 07:34 PM.
Senior Member
Joined: Apr 2015
Posts: 227
Likes: 21
I was wondering if some of you amazing internet mechanics could diagnose a problem I have on my 06 Mark LT with 3v 5.4 l engine.
I just bought the truck and when I test drove it, I made the stupid mistake of falling in love with the truck before really pushing it and testing it.
So the problem is that the truck is very sluggish. When I floor it, it doesn't accelerate very much. It's worse when I'm on the freeway going up steep hills (I live in Colorado). Often I can't keep up my freeway speed. When I floor it, it revs up and stays revved up for longer than usual because it's barely gaining speed. Cylinder 5 often misfires when I do this.
So here's what I have done so far. None of it has helped the sluggish performance or misfire issue:
Any idea what else it could be???
I just bought the truck and when I test drove it, I made the stupid mistake of falling in love with the truck before really pushing it and testing it.
So the problem is that the truck is very sluggish. When I floor it, it doesn't accelerate very much. It's worse when I'm on the freeway going up steep hills (I live in Colorado). Often I can't keep up my freeway speed. When I floor it, it revs up and stays revved up for longer than usual because it's barely gaining speed. Cylinder 5 often misfires when I do this.
So here's what I have done so far. None of it has helped the sluggish performance or misfire issue:
- Changed all 8 spark plugs
- Changed all 8 coils
- Changed fuel filter
- Changed cylinder 5 injector
- Ran a can of Sea Foam through it
- Always put 87 octane gas in it
- Checked catalytic converters. No back pressure.
Any idea what else it could be???
Thread Starter
Junior Member
Joined: Jul 2016
Posts: 21
Likes: 0
From: Utah, USA
Any codes thrown??? And maybe if not have been thrown and there's issues there may be something wrong with the warning Light I would run a code reader just to be safe . Not saying the dealer that you bought it from is Shady but sometimes they will manipulate the light I knew a friend who buy a car with the light was actually disconnected that would be the first place I checked. Also how long have you had the vehicle and how many miles have you put on it
