Hey guys,

So my transmission some how crapped out. I have a feeling that the parking garage guys may have had something to do with it. Anyway, had a rebuilt one put in by an indie shop. Transmission works fine but she idles really high, also noticed throttle really doesn't go when i hit the gas. Plugged in OBD and got P0121 and P0155 error codes. One time she shut off on me while driving. Kinda scary. Im thinking it has to do with throttle body.
Anyone know how to remedy this problem or steer me to a similar thread?

Thanks again guys.
Justin
1997 XK8 150Kmiles V8 4.0L

 

Check the throttle cable connection on the driver side of the throttle body. There are two screws that go to the bracket. When they put it back together they might of missed them. I did just after reinstalling the transmission and I had those symptoms. I didn't check to see what your codes are but it only takes a minute to see if this is the problem.

 

The P0121 is one of two problems the first a plug issue the second is the throttle body issue. Your 97 has a first generation throttle body and Jaguar had a recall but it has expired. I will attach that recall.

Now the plug in question I think will be on the right facing out of the car.

As for the P0151 that is a bank 2 O2 sensor issue and that plug or the sensor could be damaged when they put the transmission in.

My next move would be for them to look into the problem. When I had my transmission was worked on they crushed the plug when they installed the transmission and both of your problems could be related to their work.

Link to recall http://www.jagrepair.com/images/TSB/...20Throttle.pdf

Link to codes http://jagrepair.com/images/AutoRepa...%201997-99.pdf

 

Thanks guys for the rapid response.
I checked the cable and it seems fine. I don't think they touched the throttle body, I could be wrong.
Quick question, is this an issue i can maybe work on myself cuz the shop keeps telling me they only work on transmissions. Im thinking of sending throttle body out for rebuild. Anyone have any recommendations on throttle rebuild?
Also what is the location of Bank2 O2 sensor?
Also, I'll add some pics. I took a look at the throttle body connections. I know it wasn't the shop cuz it was there before I gave it to them. It looked suspicious. The wiring seems to be glued to a connection. Maybe the connector clip broke and somebody glued it on??
Thanks again guys,

Justin
1997 XK8 150Kmiles V8 4.0L





engine bay




left side of throttle




right side of throttle with questionable glued connection

 

ASI has done work for me and others on the forum. Note that P0121 could be a compatibility issue at the plug.

Link http://www.autoecu.com/index.php?p=1

 

ASI is good, I have used them for a few diff cars.

 

Hey guys,

So here's an update. I sent out throttle to ASI and they rebuilt it for me but I'm still having the same revving problem. I checked for air leaks and Made sure all seals were fixed. I noticed while driving the car kinda jumps into gear. Also she's been trembling heavily while idling. After installing the throttle she shut down on me a couple of times. I was thinking she could be misfiring which I was reassured of by my mechanic. He changed out a couple of plugs that were bad. But still I have that revving problem. Any other ideas you guys might have on what this issue might be?
I'm thinking of redoing entire wiring harness to see maybe if somewhere there's a short or bad ground.
Also, if she's been misfiring, why doesn't that pop up on error codes? I just get engine fault on the odometer display?
Kinda weird. People having been telling me it's not worth fixing and just scrap the car but I don't think I'm that far out yet. Am I just in denial?
Thanks again for all your help guys.

Justin
97 xk8 150k miles V8 4.0L

 

I can't believe you still have the throttle with the shiny metal vacuum actuator version on your car. Only the first few thousand cars had that throttle.

You can install a 'known-good' AJ26 throttle assy from 1997/1998 XK or 98 XJ (or 98/99 XJ supercharged) as they are all AJ26 engine management.

Jaguar had many issues with the throttles over the years. There are TSBs for both the AJ26 AND AJ27 throttles.

I uploaded hundreds in the large file area of many forum sections.

Try some of these.......

bob

 

Mine has the chromed vacuum adapter also. I thought it was probably a replacement and now you tell me it's a dinosaur.

I have had to clean the connectors a couple of times and I think the guard tracks have caused some cruise control interruptions, but it's still working well otherwise.

 

Hey guys,
Just wanted to update the crew on my jag.
So I figured out the revving issue. The wiring that was done with the "suspicious glue" was put in all wrong. I had a friend who's a performance jaguar mechanic take a look. He said whoever installed it put the wires all wrong so the ecu was going crazy. He fixed the wiring and now she purrs again����.
I've had a check engine light and figured out it was the O2 sensors and changed them out. Once again thanks guys for all the help.
From time to time I'll get a "coolant low" warning on the display. I'm currently searching through the forum as to rectify the problem. I already topped up the fluid reservoir.

I almost gave up on her but I figured I'd do whatever work I could on her myself and it paid off������������

I'm gonna do a tranny flush. I know Rev Sam has done a video on this but my tranny is a bit older. Was wondering if I could follow the same steps, essentially?

Thanks again
Can't reiterate how useful this forum is.

Justin
97 xk8 155k miles V8 4.0L

 

If you're going to keep the car change the main pressure valve. You probably plan on dropping the pan and changing the filter, so the valve replacement will only add a couple of hours if you work slowly. Link below explains:

http://jagrepair.com/images/AutoRepa...%20ZF5HP24.pdf