Hard to start - fuel system?

[Superkirby]

Ever since I got the Jeep, it's been a little hard to start. It doesn't matter if it's warm or cold, it takes several seconds of cranking. This can be slightly decreased by pressing the gas pedal, which would lead me to think it's fuel system related. I can hear the pump kick on when the key is turned on, so I'm assuming it's not the fuel pump. I wouldn't think it's the filter, because once it's running it runs fine.
Where should I start in trying to make it easier to start? I would like to avoid throwing money and parts at it unless I'm pretty sure they're going to fix the problem.

[nickxj94]

Start with a full tune up if it has not been done in a year or so, fuel filter, oil change, air filter, plugs, wires, cap and rotor, fuel injection cleaner in the tank,

[TheWeiss]

I am told that the fuel sending units in ZJ's and XJ's tend to go bad past 100k miles. I think the fix is expensive or really time consuming so I just live with it. Eventually, I'd like to get it fixed but I haven't gotten around to it.

Can anyone else weigh in? I'm no expert I just report what I hear...

[4.3LXJ]

I am told that the fuel sending units in ZJ's and XJ's tend to go bad past 100k miles. I think the fix is expensive or really time consuming so I just live with it. Eventually, I'd like to get it fixed but I haven't gotten around to it.

Can anyone else weigh in? I'm no expert I just report what I hear...

It is the check valve that typically goes bad. On the pre 97 4.0 it is located on the fuel rail and no big deal to replace. But on the OBDII systems with the single fuel line, the regulator and check valve is all on the sending unit in the tank and yes that is $200 and up to replace. I am having issues like that with mine, which is even more expensive to replace since I get to replace the injectors with it. So I will be adding a switch to tap into the fuel pump circuit to run the pump longer than 2 seconds when starting.

[Mudderoy]

Ever since I got the Jeep, it's been a little hard to start. It doesn't matter if it's warm or cold, it takes several seconds of cranking. This can be slightly decreased by pressing the gas pedal, which would lead me to think it's fuel system related. I can hear the pump kick on when the key is turned on, so I'm assuming it's not the fuel pump. I wouldn't think it's the filter, because once it's running it runs fine.
Where should I start in trying to make it easier to start? I would like to avoid throwing money and parts at it unless I'm pretty sure they're going to fix the problem.

http://youtu.be/pr2UzpS71HA

I bought a fuel pressure gauge and it was about 50 psi when running. When I stopped the engine it dropped to near 0 after about 20 seconds.

Bad fuel pressure regulator.

I replaced the fuel pump assembly (97+ the whole thing is in the fuel cell) and now it starts perfect.

[Superkirby]

Per the youtube video, that's about the same as mine. As far as I can tell my whole assembly is in the tank as well, correct? I very well may just leave it for a little while. Aside from taking a couple times of cranking to start, it's really not a big deal and doesn't seem to affect it.

[Mudderoy]

Per the youtube video, that's about the same as mine. As far as I can tell my whole assembly is in the tank as well, correct? I very well may just leave it for a little while. Aside from taking a couple times of cranking to start, it's really not a big deal and doesn't seem to affect it.

I don't think so. I think your fuel filter is external to the tank, and perhaps the fuel pressure regulator, however I've only worked on 97+ XJ's. Maybe Steve will pop in here and tell us both.

[4.3LXJ]

The pressure regulator is on the fuel rail. Not sure, but I think the check valve is in the fuel pump inside the tank.

[Mudderoy]

The pressure regulator is on the fuel rail. Not sure, but I think the check valve is in the fuel pump inside the tank.

Oh so perhaps my issue wasn't the regulator, it could have been the check valve. I replaced everything so no telling which part it was.

[4.3LXJ]

Tony, your return line is in the tank, as is the regulator. You have only one line out so it maintains the pressure. In the rest, there is a return line and the regulator is in the line where it comes off the fuel rail. Both check valves are in the tank and if I remember correctly in the fuel pump itself.

[Superkirby]

What all is involved in tapping a switch in? Thinking about it, while I don't see it being an issue right now, when it's -30 out this winter, it could be. Adding a switch seems like it could be vital then. Maybe not though?

[4.3LXJ]

What all is involved in tapping a switch in? Thinking about it, while I don't see it being an issue right now, when it's -30 out this winter, it could be. Adding a switch seems like it could be vital then. Maybe not though?

I bet you can't guess who has a brand new switch labeled fuel pump sitting on his desk as he types this.

Yes, that is what I am going to do.

[Superkirby]

After you do this, you should post a how-to. Very detailed please. Wiring scares me.

[Superkirby]

Also, will it be set up so that with the switch off the fuel pump will still cycle on normally? Or once the switch is in will it have to be on for the vehicle to work?

[4.3LXJ]

Yes, it will function normally. It will be for starting purposes only. Might be about a week before I install it