Kyle Bertrand

My 2000 jeep with the 4.0 recently starting an issue where it has a long start and I have to push the gas a little get get it going but once it turn on it idles and runs just fine. I rented a tool and tested the fuel pump today and it would go up to 46 psi and after more the 20 minutes it only went down to about 35 psi. My volts have been running about 13 on my dad's when I'm driving but sometime it will stay at 14.

agreen

How's the compression look?

Kyle Bertrand

Something I will have to check but like I said it runs fun when it starts and it doesn't do it all the time. It was starting right up most of the day today.

Lordmonk3y

What do you mean by long? I've always felt like these jeeps take awhile to start compared to every other car I've owned. My 94 xj with a bran new engine cranks for 2 whole seconds usually. Always has.

BruceB

It is possible that an injector is leaking and reducing the pressure in the fuel rail when the motor is off. If you go to start it, just turn the key to the "on" position until you hear the hum of the fuel pump go off and then start it. If it starts quickly you may want to replace the fuel injectors, or have them tested.

hope this helps...

Kyle Bertrand

I can check the Injectors but I just replaced them a year and a half ago from some from Ksuspenions but if they're bad I think they have a lifetime warranty. Of course since I made this post the jeep has been starting just fine.

BruceB

The Jeepster is setting you up.....just when you think it has "fixed itself" it will leave you high and dry in a lonely place with no cell phone coverage....

And whatever you do, never state that it is "running good" as that is a call to the Jeepster Jinx...

But seriously, you are having an issue flare up and you should go through a diagnostic procedure to try and identify what led to your start up issue. Could be a number of things as these Jeeps have age and time deteriorates all things...

Kyle Bertrand

So obviously it's been doing it about but I've found that when it does I can cycle the keep on and off about 3 times and then it will start perfectly and after that it will start good for a little bit. Could the fuel pressure regulator be causing the problem?

Lordmonk3y

Fuel pump, fuel filter, and fuel regulator could all cause that issue. That's definitely a fuel pressure problem.

agreen

Fuel pressure is bleeding off.
-There's a check valve in the pump
-An possible leaky injector
-An external leak somewhere (not very likely, but possible)

Kyle Bertrand

I rented that tool and checked the pressure at the fuel rail and it went up to 46 psi and after about 25 minutes of letting it sit it went down to about 35 psi. I'm not a mechanic so I don't know if that's good but from what I read online I guess it is.

Lordmonk3y

But did you have to cycle the fuel pump (turn key on and off several times) to get it to that level or does it reliably hit that level cold? If you haven't used that test tool after its sat awhile then that might be a good idea.

Kyle Bertrand

My jeep is daily drive so it doesn't sit without driving alot but I didn't cycle the keys when I tested it. I turned the jeep on and it went right to 46 and then like I said I let it sit for over 20 minutes

Lordmonk3y

The times that it doesn't want to start right away. Can you hear the fuel pump kicking in? I'm wondering if maybe you have intermittent pump issues.

Kyle Bertrand

I can try and check it but it's so random when it doesnt want to start. What would cause intermittent pump issues, just a bad pump?