Bad fuel pump?

[XJSpooner]

OK...so, my '99 Cherokee Sport (which I've had for about 2,500 miles so far) has always started a little rough, usually requiring two starts to get going but is always fine after that. It still requires a "double start", but now it has started to "hiccup" as if the fuel pump is intermittently delivering fuel - it surges repeatedly, requiring me to pull over, put it in park for a moment, and then resume. After that, things are normal, but it's definitely getting worse. Could this be a fuel filter? The whole pump? I recently had a minor OBD2 sensor issue, but that was just rusty connections. Any advice would be much appreciated.

[4.3LXJ]

Nick, it sounds like yo might at least have some check valve issues causing hard starting. But to really diagnose that, you need to monitor fuel pressure. To fix that check valve, you will need to replace the whole fuel pump assembly. IIRC that is the only way it comes. So being a little expensive, a proper diagnosis is the thing to do first. Any check engine lights?

[XJSpooner]

Thanks for the reply...no check engine lights at all. If the car sits overnight, the first startup and run of the day goes smoothly and without the "lurching" issues. But if I stop for an errand and restart, the lurching begins. It will also stall during these lurching episodes, but like I said, once it's running it will go with zero issues.

[4.3LXJ]

I would also ask when was the last time the crank position sensor was changed. If you don't know or it has not been changed in the last 100K, I would suggest changing it both as an answer to your problem and a preventative measure. They don't last forever and can give symptoms as you describe without generating a CEL

[07Negative]

If in the end you do need a fuel pump. I have a spare I'd sell you. From the Same year XJ. I picked it up off a fella going out of business near me.

[XJSpooner]

Thanks Steve - on a scale of 1-10, how hard is it to change the crank position sensor? I think I'm gonna start there as a preventative step at least. If it's the pump then I'll cross that bridge next.

[XJSpooner]

Thanks Deejay...I'll hit you up as soon as I suss out what's going on. If it's the fuel pump I will totally take you up on that.

[4.3LXJ]

Pain to get to. But two torx bolts does it. Most go at it from underneath. I would replace the torx bolts with regular hex head bolts while they are out. It will be much easier next time that way

[Carves]

Thanks Steve - on a scale of 1-10, how hard is it to change the crank position sensor? I think I'm gonna start there as a preventative step at least. If it's the pump then I'll cross that bridge next.


Tis easy to get to ...

Just remove all the bits that get in your way ... and there it is .. :D:D


http://i1143.photobucket.com/albums/n629/carves-oz/Vehicle%20Bits/Engine/EngineA03.jpg


Access from underneath as 4.3LXJ said ... some remove the front driveshaft for a bit more room ... many use lotsa socket extensions.

Could be bolts or torx heads ... probably bolts on the later ones.

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