I was driving up the road yesterday and my truck just lost power. It still runs but it runs rough almost like it isnt hitting on all cylinders. I still have decent fuel pressure to the vp and I dont have any codes. I have unhooked my tst and used the superchips tuner to go back to stock programing. I pulled the valve cover to make sure that I didnt bend a pushrod or something but everything is ok there. There is no signs of a blown head gaskes either. Im not sure what to check next. Do you think my vp just took a crap? It has 141,000 miles on it. Any help would be greatly appreciated. Also how do I do a compression check on a 24v?

 

Do you have access to an OBD-II reader? Very handy to get if you dont have one.. to hook up just to see if there are any obvious problems the computer knows about.

Some have had a random loss of power before losing the VP completely.

Running rough can also be attributed to a lack of boost pressure. The fuel systems on these trucks could be a little smarter (based on boost pressure instead of throttle position... what the heck were they thinking?) so if theres a leak anywhere in the intake tract the truck can run rough because its dumping fuel expecting boost to follow.


Any smoke or smells?

 

Is it smoking?

 

I have checked for codes and it is not showing any. I did a check of the intake and found no leaks. I ran it and it builds boost. It really isnt smoking eather.

 

Stupid question: is there enough fuel? Maybe it sucked in some air?
-P

 

The VP going south is ALWAYS a possibility - and I'm not sure that it will throw a code in every instance! Anybody know of a way to test a VP that may be dead but hasn't thrown a code?

Another thought - perhaps you've had an injector go south, or the IC has a leak, are you still making boost?

 

Have you hooked up a fuel pressure gauge to see what you are getting? If you think that it might be fuel related I would start there.

 

Sure,

Same as bleeding the lines after replacing a VP.... crack # 1 and #3 injector lines and see if you are getting a solid spray of fuel or just a dribble. Best to place a piece of cardboard behind the open lines to get a good picture of the spray.

 

Thanks guys. I will try cracking the injector lines today. I know the lp is working because I still have 12 psi to the vp.

 

Make sure you eliminate bad fuel/water in fuel as a cause before you R&R the IP w/o a code.

 

I have cracked the lines at the head and they seem to be flowing fuel but its not spraying out that hard. How hard should it come out?

 

I suppose pretty hard at some 30,000 psi, provided you cracked them enough (not to come off completely!)
-P

 

30,000 psi???? ARe you nuts.. That may be for the common rail third gens, but I thought the 2nd gen 24Vs ran the same pressure you see at the pressure gauge.
You should see pressure, like putting your thumb over the end of a hose....

Where in Maryland are you???

We have great suport in the Baltimore area.

 

MD Chapter is great and a lot of help. Get in touch with us.

BTW - the pop-off pressure of the injectors is ~4500psi so I would think the pressure at the connector tube would be much higher than fuel pressure to the injector pump. Not as high as a common rail, but a bit more than a hose.

 

Stock rail pressure shouldn't exceed 27K psi