Great site with tons of useful information. However, I haven't been able to find an answer to my problem after much searching and reading most of the fuel pressure related threads.

Problem.... Fuel pressure drops to 7 psi ONLY at idle after the truck warms up. As soon as I rev it up a little the pressure rises to 13 psi. Normal pressures are idle 13 psi, cruise 11-12 psi and WOT 8 psi. This problem started several weeks ago. I changed the LP in the early summer with no problems until now. I have an EZ with the boost elbow and gauges. The problem occurs with the EZ in and out of the system. I have FP gauges pre and post filter and both act the same. I've had all connectors off and cleaned them. I've had the IAT out and cleaned it. Still have the same problem. I haven't checked the voltage at the LP (have to bare some wires) but it almost appears that the pressure drops to half of normal as if it is getting starting voltage instead of running voltage. Can anyone help?

 

My roommates truck does that except it bounces from 15 to 0 and any where in between at all times. Took it in for Dodge to change it, said the pump was good. Pump had about 6K miles on it when it started doing it. He to has an EZ and it does it with or without it.

 

Mine doesn't bounce, it just drops from 13 to 7 and holds rock solid until I rev it a little then it will move up to 13 again and stay there for about 10 seconds before it drops to 7 again. That's what makes me think it may be something other than the LP because it isn't erratic.

 

Same scenerio my Holley had. I verified my sending unit wasn't the culprit, changed the fuel filter, no change......FP all over the place. Ditched the electric pump (actually use it as a back up) for a mechanical pump, problem solved.

...I'd say your LP is on it's way out. Get it replaced before it quits for good and you damage your VP $$$$

 

Ok. I've read threads on fuel pressure that are ALL over the chart. Can someone tell me what the stock readings should be? What does Dodge say is "good" pressure? At idle, WOT, etc??

 

I believe it's:
around 15 at idle
around 11 normal flat road driving
no less than 8 WOT

 

Actually, DC uses volume instead of pressure to determine lift pump efficiency, but the numbers above are correct for a stock pump. When I first replaced my LP a year and a half ago, my numbers were 16 psi at idle, 13 psi at 60 mph on the flat, and 9 psi WOT. Now I get 14.5 at idle, 12-13 at 60, and 8 WOT.

DeWain