My truck has lost power off the line. Its very sluggish until it gets to about 1800rpm and the turbo spools up fully, then its goes OK. As long as its on the turbo, it feels fine, but something is really wrong with the power. I have a vegi oil kit installed, but this is when Im on Diesel or Vegi, doesnt matter. I replaced the fuel filter, which was pretty clean. When I hand primed the filter, there was some fuel on the lift pump so that might be leaking? I dont have the common ticking of a bad lift pump at idle. I dont know what my fuel pressure is because I have no gauge. My air filter is clean. The exhaust is smokeless and normal at any time when driving, WOT or idle. It seems to get worse as i drive (stop and go) and the engine will almost die if I blip the throttle. Any ideas?

 

check your overflow valve and your preheater screen..probably the preheater screen ..

 

Check to make sure theres nothing wrong with the AFC too. Maybe take a spin with it off and see what it does. Its possible its not getting air pressure to push on the diaphragm / spring.
You can pressure test the air intake by putting a PVC pipe cap in the intake hose and screwing an air chuck into it. 15psi should tell you if theres a leak.
Otherwise it could be fuel pressure (overflow valve, filter or dying lift pump), timing, or a governor arm adjustment.
Theres a writeup on piers diesel site that says how to adjust the governor arm if you need it. It helps to have the arm contact the plate a little higher for more low end power.
Id look into a fuel pressure gauge soon, especially since you have a veg conversion. Theyre really helpful to have. Vulcan performance can sell you a nice setup for losing the IP fuel intake banjo and creating a spot for a pressure sender.

 

if it dies when u bump the throttle your idle is to low,or u might wanna turn ur aneroid vavle a little bit to give it more low end power

 

the pre heater screen was dirty but i did clean it, same crappy power. what is an AFC? and ive read into the overflow valve, but i dont know where it is or what it does.

 

AFC is on top of the pump with air lines going into it. The metal 'foot' in there keeps the governor off of the plate until you build some pressure to push it out of the way. If its not getting pressure it can hold back your fueling.

 

What's your idle rpm?

 

about 450 in Drive. about 700 in park or nuetral. im replacing the lift pump today so we shall see.

 

Whoa, before you replace the lift pump, go ahead and set the idle. Should be 750 to 800 rpms in D with the A/C on full blast while idling. Info can be found here:

www.dodgeram.org

The lift pumps don't really need to be changed on the 12v's. If you've heard about a lot of people replacing them, it's because they have 24v's.

 

My bet is your AFC diaphragm is cracked.

 

well i didnt try the lift pump yet. i took one look at what it would take to get that thing changed and figured id start tomorrow. i think it will require me to remove the starter to get at it from under the truck. since its pretty cheap, im going to replace the overflow valve and research the AFC thing too. **** this is bothering me, i cant even beat a honda civic off the line.

 

maybe the line goin to your afc housing is loose or pinched off and that would cause loss of power