I have 1999 dodge diesel, when I reach speeds of 50 or above I loose power. The engine does'nt die just no power. I have a fuel pressure gauge, it stays at approx. 9 or 10. Just wondering if any one knows what I could look for to correct this? TIA

 

Check your codes and list them. That may give us more of a clue... see if someone else may chime in with an idea here......

good luck

note: you can read codes by turning key on and off 3 times... it will read out on the odometer display

 

One thing to try is to try and raise the idle above 2K rpm when you are stopped and in neutral. If the engine stops at 2K, you are in limp mode and need to check codes for the problem.

 

99's don't have the key code reader.
I would suggest going to Auto Zone or other parts store and have them read the codes.
When was the last fuel filter installed?? maybe change it.
When was the air filter installed ??? maybe change that.
Your fuel pressure is on the low side unless you have the intank pump.. Still low. You may have a lift pump on the way out unless it is very very cold there.

Get the codes read and fill out your signature. (tells us about your truck) Use the UserCp above the forums.

 

Bentwings has good advice, but I believe Autozone will only check for codes if the CEL is on....

You have a FP gauge, do you also have a boost gauge? Any abnormalities there?

How strong does it run up to 50, or are you in limp mode, and 2k rpm limited?

 

Actually I ran it again today and fuel pressure was actually at 10 or 11 at about 55mph. It does have new filters on it. It also has a new lift pump. I have no boost gauge. It seems like it loose's power at different speeds 1 time at 40 mph. it lost power, put it in nuetral and rev. it up tach went up but still act like no power. Put it back in gear no power, wait a second or two then it kicks in with power and picks up speed. Also running straight exhaust pipe, so I can even hear when it kicks in and out. Any other advice? Its hard to find anyone around here to run codes. TIA

 

No boost or pyro.....spendy additions, but awfully helpful in monitoring engine health and troubleshooting same...; It does sound suspiciously like a dying VP44.

... you may be experiencing the first Death Throes of the VP44, about the only thing I've read on this site that may be an alternative (based on the loss-of-power description) is an out-of-spec APPS (requires a reset).... I hadn't strongly considered the VP44 as the problem until you described the Dead Pedal syndrome - anyone else want to chime in on this one?

You can clean the MAP and IAT sensors to eliminate them as sources for your ills; I've seen a few posts that profess that the bypass valve was the culprit, you could swap this out as well,

The APPS reset procedure can be found at:
https://www.dieseltruckresource.com/...d.php?t=108202

God luck, keep us informed as to your progress -

Rauschbo

 

Rimfire - why don't you fill out your sig?