fuel delivery is a strong contender. check pressure at the rail. still, iacv is easiest.

 

I have an IACV enroute (ordered it the instant I read your first reply lol). I should be able to snag that pressure tester tomorrow. I won't be able to wrench on it until closer to Friday but I'll start spraying fasteners with penetrant today

As for the revving - I can rev it in neutral or park when its cold. I get no power and no revs above 1100 ish. I can nurse it forward and back just not above 10mph. Since I've had it (and it was running) I've noticed it will idle smooth, then suddenly rough idle, then smooth out again. Besides checking the air filter (which is clean and std paper cartridge) I was planning on getting some throttle body cleaner and making sure its not too gross up at the top end. Its consistently run colder than I would like according to the ultragauge - typically around 160-170. The hottest it ever got was 206 climbing out of the Phoenix valley. I have a new 180 tstat I plan on putting in on wrenching day.

 

You can clean the IACV - I would go that route especially if it is the OEM LR part - just soak it in carb cleaner for a couple of days and it will be as good as new

 

take the time to clean the throttle body while you are in there. Let us know how it goes.

 

The screws on the fuel pump cover plate are threaded into plastic inserts on the body. If you can grab them with pliers, they will tread out. Replace with new ones (stainless to keep from rusting)

 

So I finally got a not miserably cold day today (and all my parts had arrived) to troubleshoot the disco. First thing was just a thorough inspection of wiring, hoses, etc. Nothing out of place. Unplugged the TSS...no change. Cleaned and reinstalled IACV (have another on the way - cheapy Amazon one was not clocked correctly) with no change. Replaced fuel filter...also no change. Finally I got the carpet up in back and installed the new fuel sender/pump unit....and SUCCESS! In the end it was a bad fuel pump. @binvanna was correct. She's back on the road. Next tinkering will probably be sorting out why all the ABS fuses are pulled. And lowering it down lol. I was very impressed as to how clean the throttle body was. My 2001 was constantly gunked up.

Thank you all for the guidance!

 

About ABS, my trucks both have the fuses pulled because ABS will kick in unexpectedly during slow turning situations, like in parking lots or at the edge of a cliff. This causes the trucks to keep rolling. In my cases, it only caused moments of terror. In other cases it has lead to accidents. I decided I will pump my own brakes and pulled fuses after multiple attempts to fix the problem. In my case, leaving ABS fuses pulled is probably safer on the road and off.

Congrats on solving the fuel pump issue.

 

Oh my! Well that explains why these are pulled then! I'm not really up for that kind of excitement in my life so I'm just going to let that be.

 

John, do you think that’s more a D1 issue? I’ve had my D2 for over 3 (4?) years now and have never experienced that problem.

 

I think that could be so. The front hub geometry changed significantly from D1 to D2, as well as positions of the ABS sensors.

My theory is the magnets in the ABS sensors have weakened over the years. Not yet willing to spend on new ones to experiment. I could get it to work well by reseating the ABS sensors (only a millimeter or so), but would only last a drive or two. Slow sharp turns were the worst for causing the problem. Maybe affects early '90s Range Rovers or Defenders, but I haven't researched that.