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4.7 Engine jerking/tugging when accelerating

9K views 5 replies 2 participants last post by  i0r15 
#1 ·
Hey all!
Sometimes when accelerating the engine starts jerking/tugging a little, but then kinda gets into mood and accelerates good..
I also feel the whole car shaking/vibrating when standing still at idle...
I've also noticed an increse in fuel consumption since a while back.
Did new plugs a little while ago, but no change.
Any ideas what it could be? I got no codes or nothing... Dealer checked with their scanner as well, but got nothing..
 
#2 ·
I would start checking the fuel pressure. I had it happen on my 4.7 that it struggled a bit during acceleration and mpg went down. Changing the fuel pressure regulator solved it for me.
 
#4 ·
There is a schräder valve on the fuel rail on the right hand bank (seen from drivers position). It should have a plastic dust cap on it. You can put a pressure indicator on this valve to measure the pressure. I don´t have the specifications of the WK right now, but the pressure should normally be around the 45 PSI. Or you could save yourself this test and eventually cost of pressure indicator and change the fuel pressure regulator right away.
 
#5 ·
Thanks Frango!
Lol I honestly thought that schrader valve was for the ac...
What I can't seem to find is the location of the pressure regulator, nor part no..
I found a diagram for -05 wk's i think it was, where it said it was under the passanger floor near the wheel well. But doesn't seem to be the case for the -09...
 
#6 ·
Update!! So during this issue I never checked any codes. Though a few days ago ABS/Service 4x4 came up everytime I started the truck up.
So I hooked up my superchips tuner and got the following DTC's
C100A - Left front wheel speed sensor circuit
U0415 - Implausible data recieved from ABS

I had a lug nut on the front right wheel get stuck 2 weeks ago. Took it to a mechanic that had to drill out and replace the stud. After that I also noticed the brakes struggling from time to time when breaking light.

So now I'm thinking that maybe it's not fuel related at all. But ABS sensor sending brake fluid, applying brakes. Therefore the jerky acceleration and breaking...
What do you guys think about that??

The only odd thing though is that the code says front LEFT sensor... And the mechanic only worked on the RIGHT hub....

Anyway I'm thinking about replacing both front sensors..
 
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