After all you've been through, I would think a code scanner would be a minor and sensible investment.....
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I agree with Markus- For an entry level give some thought to an ELM based scanner (Google it) and consider the ProScan bundle. I had some "issues" with it early on and their customer service can be a PITA (if they give any customer dservice), but the latest version works good with all my OBD Jags and it will scan , reset and chart the OBDII parameters pretty darned good.

 

Thanks for the input. I'm looking for a scanner now. However, after reading my last post above, I realize that I did not explain the most recent behavior exactly. When started, the engine immediately goes to about 3,000 rpm, starts to miss and drops down to about 2,600 rpm, smooths out and goes back up to 3,000, and repeats this behavior until you shut it off. One note: I did clean the throttle body out very carefully when the engine was apart. I did not take the throttle body apart; I just gave it a good surface cleaning, inside and out. It doesn't seem to be sticking at all; it is just not controlling engine speed.

Any other ideas out there?

 

loose electrical connector? BIG vacuum leak?? Screwed up the TB?
Get the durned scanner and fix this thing!

 

OK, I got a code reader from AutoZone and got the following results:

P1601 (1 current, 1 pending)
Manufacturer Control
Auxiliary Inputs
Auxiliary Outputs

P1000 (pending)
Manuf Cntrl Fuel & Air
Metering, Auxiliary
Emission Controls

P1797 (pending)
Manufacturer Control
Transmission

I tried to reset the codes and the P1601 and P1797 reset fine, but the P1000 would not reset.

Can you tell anything from the above information about where I should be looking now? Thanks in advance for your help.

 

Some of what I am about to tell you may be partially right:
First, for sure, the P1000 code simply means that you have reset the ecu and not finished an OBDII drive cycle. (Google that for more info. It will change to P1111 when it does
The other two are sorta wierd. They mean a CAN communication bus failure between the ECU and TCU. I had convinced myself that most reports of this were from connecting the scanner itself- its on the CAN bus. However, in your case, the light came on before you connected the scanner. And you have symptoms. I still believe most reports are for the scanner connection, but I believe you should check out the connectors at the TCU and the transmission for corrosion.
JTO mentioned on another thread, I believe, that he knew of some throttle body- CAN fault relationship.
I have gotta say, I really believed you would find a smoking gun with the code reader! And you have not got one. I would reset the codes, reset by battery disconnect, then look at all the connectors you removed for the engine work. Especially around the throttle body.
You don't suppose the underground parking garage flooded and caused all of your seemingly unrelated problems, do you?

 

I am pleased to report that my XJR is back on the road again! I finally found cause of the latest trouble. When I had the engine apart, the throttle cable was, of course, disconnected from the throttle body, and somehow the adjustment "ring" that determines the range of motion of the cable got turned several revolutions. This caused the cable to be too short when re-installed, and the throttle would not close fully at "idle". I took the cable off of the throttle body and the car idled, but you could not increase rpm. I then re-installed the cable and turned the adjustment "ring" so that the throttle plate was just closed with the pedal at its maximum height. I started the car again, and voila!, the car ran perfectly. I had to adjust it again with just a little more tension, and now the car runs great. Very smooth, very quiet, no unusual noises. I'm very happy that this job is finally done. If I had to do it again, I think it would be pretty simple after having been through this and learning what to do the hard way. I just want to thank all of you that contributed your advice and ideas!

 

If you had the kind of scanner that reported parameters as well as codes, even without the Jag specific stuff, you would be able to read the throttle position. Since you obviously are capable of handling your own maintenence, I recommend you get something like AutoEnginuity with Jag extensions. I bet you pay for it on the next problem you have. Troubleshooting with a good scanner reduces buying unneeded parts and makes MOST diagnosis go much faster.
Also, then, I return to my contention that codes P1601 and P1797 are usually an artifact of connecting the scanner.

 

Glad to see you got it resolved. I agree with Spark, the AutoEnginuity software scanner with the jag extensions (~$500) would have told you very quickly what your throttle position sensor was and any given instant. If you forsee more DIY projects in the future, that would be a sound investment. Lookem up, the enhanced features are mindboggling...live transmission data, 02 sensor readings, the works.

 

I just replaced my Fuel Pumps using the "Don't Release Fuel Lines" method. Well, I pulled one of the metal tubes right out of the tank. I had already read your warning, but I had my 25 year old Son-In-Law helping me and he gave one of his "Hercule's" tugs on the tank to move it. Doh!

Luckily for me, I was able to reach up in there (Extremely Hard to do), and bend the pipe back to shape and insert it back into the tank. Low and behold, the clip was good, and it sealed right up. Been driving it for a few weeks now, and no leaks, so guess I lucked out. Mine also had no clamps holding the rubber lines to the metal tubes.

I too, recommend removing the lines if you can do it. It's going to be VERY hard because there is only one small angle to get an arm up there, and it has to be a small arm.

Also, after reading your post, I added Duct Tape to the hole on the top of the tank. I did still get cut when the tape adjusted at one point. Dang that thing is SHARP!

I was very happy to see I had ZERO dirt or contaminants in the tank. It litterally looked brand new inside. I'm hoping that meant the previous owner always used good gas, as I do.

On the up side, the car drives like a new car, especially during Hard Acceleration. I guess I've been suffering from low fuel pressure since I bought it. Much more power than I've ever had.

Thanks for the tips on getting the fuel pumps out! $224 for BOTH pumps and a bit of hard work, but well worth it.