96 XJ losing fuel pressure?

awinterstale

awinterstale

New member
I have a 96 CJ with the 4.0L and it has a really long crank time. If I cycle the key a few times it starts quicker. I checked fuel pressure and it takes a few key cycles to get over 30psi and start the engine. I replaced the fuel pump and still have the same issue.

It runs fine once started, FYI.

Any ideas, maybe leaking injectors and need to replace O-rings?

Thanks for the help
 
Richmech

Richmech

New member
Check the fuel regulator? After primed how long does the pressure stay? Did you replace the fuel filter also ?
 
awinterstale

awinterstale

New member
Did not replace filter because once it's running it runs fine. After it's primed it starts to loose pressure almost immediately
 
Richmech

Richmech

New member
When you replaced pump did you replace the hose between pump and housing, and did you use new hose clamps? The fuel pressure should hold for approx 10 to 15 minutes before dropping.
 
awinterstale

awinterstale

New member
Definitely a quicker start with the new o rings, but still has a long crank time if I don't cycle the key 2-3 times.
 
DIRTRIDER

DIRTRIDER

New member
It is not necessary to repair "O" rings if you do not see they are leaking.You should better check :

1.Fuel pressure (the fuel pump) or fuel regulator (if you telling us that fuel pressure is raising up before you starting to crank)
2.Crank Position Sensor
3.MAP sensor

This is only three main things that could be a problem on a amc 242 for start...
 
P

Petej

New member
1996 uses a return-less fuel system. The regulator is part of the pump assembly in the tank. Check all the lines on the in tank assembly. If they are cracked, you won't have any external leakage, but you will have low fuel pressure.
 
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