2000 XJ, 4.0 and 250K miles. When I start it up on cold mornings (been below zero here in the AM) it won't hold idle at all, and will die the second I take my foot off the gas. When it warms up after a few minutes of driving it will idle, but sometimes it idles low. It will also idle low at seemingly random times after I have been driving for a while, like at red lights or in parking lots. Other times it will idle fine.

I have replaced the TPS a couple years ago, and I just cleaned the idle air control valve a few weeks ago (I suspected this was the cause, I have cleaned it several years ago to solve the same problem) to no avail. I just got the battery and alternator checked at autozone and they say they are fine. Other than a possible vacuum leak somewhere, are there any other common issues I should look at? This was not an issue at all last summer, and like I said above, I have fixed it in the past with cleaning the IACV.

Any help would be great!

Thanks!

 

I just posted a thread about this same issue... I will post it for ya here....


probably the same issue?

 

The issue is the fuel pump is weak. Had a 92 with a similar issue. Fuel pumps in XJ's are notorious for getting weak, but not completely going out. I would know, i've owned 6 of them.