hando

My 1997 XJ 4.0 starts losing fuel pressure slowly after its been turned off. What can cause this? Overall it starts fine and runs but it idles low.

ezab

The fuel pressure falling is normal.

Alaskan xj 97

Your oil pressure will lower when hot you have mechanical fuel pump that runs by engine so more throttle more pressure less throttle less pressure
Hello from a 4th gen Alaskan and jeep driver my great gramps drove a old military jeep up hear in 1940's.

ezab

First off he has an electric fuel pump, as far as I know all Cherokee's have electric pumps.

ezab

Engine at idle 49.2 ±5 psi
Fuel Pressure Drop (pump not engaged) Not fall below 30 psi for 5 minutes

Alaskan xj 97

My xj has a mechanical fuel pump found out when friend left on steep hill in third rolled down hill and flooded it

ezab

I honestly don't think you know what you are talking about.

Alaskan xj 97

If you take a look at jeep Cherokee haynes repair manual you will see some Cherokees do have an mechanical pump believe me it sounds like you dont know as much as you think you do

hando

Well the pressure is in spec at idle but after 5 minutes it gradually goes down to nearly no pressure

ezab

I would say you have a bad regulator/filter. Replace the fuel pump assembly.

Alaskan xj 97

Go buy a jeep Cherokee haynes repair manual has it all

CJ7365

Well, you need to learn to read.

He has a 97 xj it has an electric fuel pump

ezab

It says on the V6 models, the 4.0 is not a V6. Jeep used a Chevy 2.8 V6 back in the 80s for a year or 2 that did have a mechanical pump. The 4.0 never did. Before you read your book could you take a picture of your mechanical fuel pump and post it.

Alaskan xj 97

Easy buddy I just happen to be a certified mechanic what are you a
librarian

Alaskan xj 97

Enough is enough you might be rite but I will tell you my jeep has a mechanical fuel pump