I checked the fuel pressure on the the fuel rail on the 4.0.

It said 30 psi. Is that normal? Should it run at 39 or 49 psi?

Was just curious.

 

My manual says 49psi +/- 5 psi.

 

Hmm weird cause previous owner put in new fuel pump just before giving it to me. But it's a Chinese brand though.

Would a low fuel pressure be the cause of hard to start up?

 

Don't know enough about them to answer that but the lower pressure may be due to a partially blocked filter.

 

Okay, On the WJs, the fuel filter/pressure regulator is mounted on the frame near the fuel tank and is easy to change. Even if it was new when the pump was changed, knocking the tank around during the change could have stirred up sediment that had settled and partially plugged the filter or the pump pickup screen.

IMHO, the best and cheapest thing to do is change the filter and check the pressure. If it's good right after the change, you're good to go.

This is based on my problems with a Dodge Caravan. The filler pipe rotted out and allowed road debris to enter the tank. After I made my own filler pipe, the pump quit. I took it to the Dodge dealer and they changed to pump. They saw my homemade filler pipe and never thought about it. A week later the new pump quit and they replaced it with another one at no cost. They didn't clean the tank out even then. A month later, I started having fuel pressure problems AGAIN so I pulled and cleaned the tank myself and changed the filter. Guess what? No problems after that. That pump cost me over $300 PLUS the heartache of having to do it twice!

 

Thanks! I ll check into that!

 

So lately the WJ started to act up.

When I go to start it up, and when I turn the key, it's all quiet, no cranking or anything. I try again, then it would start cranking. Maybe stumbling, but wouldn't fire. On third or fourth times, if would crank and start up quickly.

Would it be a crank sensor?

 

Check your positive battery cable clamp. It's probably not making a good contact with the battery post. Each attempt at starting gets it hot and eventually burns itself a connection.

 

Dave ur right, the wire to the starter on the solenoid was loose. Tightened it up and it start up. Then I replaced the external fuel filter and now it starts up right away. Much better than before.

New question.

My girlfriend tells me that the WJ started having the wobbles. Could it be the track bar going bad, just like the XJ Cherokees? I noticed it's one piece unlike XJ's.

Do u know any other causes for the wobbles on WJs?

 

The front end has the same design as the XJs and ZJs except for the track bar's mount on the frame. The causes of death wobble are too numerous to get into here, but you can research it on this site quite easily.

There are differences between the shakes and the infamous "Death Wobble". DW occurs when the whole vehicle shakes like it's coming apart and you can't steer it. A mild shaking can be just tire balance. The only way to get out of DW is immediate heavy braking.