I was adjusting the throttle cable as seen in another thread here and noticed that the butterfly flap seems to close quite slowly compared to others that I have tinkered with.

I saw the info on possible throttle body recalls, but I am not sure if mine was or should have been serviced under this. Also, I am not exactly sure what the reason for these recalls was (I have no clue actually).

Slow throttle response was what led me to be adjusting the cable in the first place.

Any insight on this?

 

If you've seen a recall notice, then there must be a TSB. Do a search for them here and at http://www.jagrepair.com/S-TypeTSB.htm

 

I have not seen a recall notice. I just bought the car at auction. I don't know if this was one of the affected vehicles, and if it was I do not know if the repairs were performed.

Other than reading some threads here and seeing that such a recall notice does exist, I know nothing about it.

If there was a recall on mine, repaired or not, it may have nothing to do with the problems I have been having.

What I am calling a slow closing of the butterfly flap may infact be perfectly normal for these cars. I don't know.

 

I was just going down the list under the Jagrepair category for the XJ8 and noticed TSB 3-158 for wood trim refinishing. I sure would like to have this done on my front right door. How do I know if a TSB is still open active?

I haven't gotten as far as the throttle body one yet. Can anyone post the TSB # for that?

 

With everything turned off and me poking the valve to fully open and letting go it snaps closed. If there's a TSB it could be in the large files section https://www.jaguarforums.com/forum/g...r-index-50609/

 

That is what I was expecting. A snap shut. It closes SLOW. It is so slow that I would not be afraid to put my pinky finger in it and let it go. I am going to go see if I can time it right now.

I read the couple service bulletins on throttle bodies for this model. They do not seem relevant to the problem.

I also answered my own question about the wood trim...a warranty issue that I wish the original owner had addressed. The trim piece on the passenger door looks almost like it has a bleach stain under the polished surface.

 

I believe the throttle body on these has a motor on it, even though it's cable operated, which can force the valve to a certain position if the computer deems it necessary. Maybe something went wrong with that mechanism? I think I read somewhere that when you switch the key to ON, before turning the engine on, during the system check said motor will open the valve completely and close it. You can disonnect the intake tube and watch. Worth reading through JTIS and the engine repair course guide, think I read that in one of those two places..

 

I will try this too when I go outside. I still have not gone out to look at it because my children have not gone to sleep yet. Almost...

 

With everything off, it closed even slower in the sub-freezing night. I stopped counting after ten "one-thousands." I was only at about three in the daylight. That was with everything off and me pushing it open with my finger.

With the key on and engine off, it snapped shut fast. By pushing the accelerator, I was able to open it a lot further before the key was on though. With the key on, the pedal only allowed me to open the throttle a very small fraction. Then the device's motor slowly opened it the rest of the way. Wide open throttle took about ten seconds.

The vehicle is currently in Restricted Performance because of a low coolant level, but the slow opening of the throttle seem to correspond with the sluggish acceleration I was feeling to begin with.

The car goes fast. I mean vision-blurry fast. It would just take quite some time to get up to those speeds. Even merging onto the expressway was slow, even frighteningly so. People would steer left to avoid me and I would pass them all a minute or two later.

How long should it take for the throttle to go wide open?

 

You can read through this one, maybe the same?
The OP changed the bearings in the TB.

link: https://www.jaguarforums.com/forum/x...ncerns-159443/

 

Eric, I had to delete my post because I was going to respond with the same link. you just beat me to it...

Anyways, Fast.. The link that Eric posted will be your same problem. I had to look at your profile to see that you have a 98' XJ8. Providing that small piece of information is important. If you warmed up your engine to full temperature, does the throttle body react faster? If so, then that post will give you an idea what needs to be done. Btw, there are 5 bearings in all that need replaced, not 3 like I posted.

 

I am having some cooling system issues and a subsequent flooding problem that I am trying to address at this same time, so bringing it up to temp is not an option just yet. Currently it is in restricted performance also, so that needs to be corrected to compare apples to apples.

The symptoms mine has are similar yet different than what was described in that other thread. The exact condition of my throttle body is as follows:

Butterfly-flap opens freely via my finger being stuck in it. The operation is smooth with the to-be-expected resistance from the motorized mechanism. When the key is on; it does snap right back to the closed position just as fast as any that I have seen, so my initial observation of a slow close did not take into consideration the need for the computer to be on for proper operation.

The throttle body is clean too. It is really clean actually, especially considering the amount of blow-by oil that was in the intake tube. There is only light corrosion/pitting on the outside of the unit. A zip-tie on the cable retainer tells me someone had tightened it once before.

Even before the overheating and restricted performance, acceleration was sluggish. It is the worst car I have ever tried to pull out onto a busy Interstate with. It will go well in to the triple digit MPH, but cannot spin the wheels from a standstill.

 

BE CAREFUL with the throttle when the key is ON. The motor is quite powerful and might trap/damage a finger!!!!!!!!!!!!

TSBs are NOT recalls. Jaguar will perform the service stated in the bulletin but not for FREE unless the car is under FACTORY WARRANTY.

bob

 

Yes, I could see a clear difference with the key on vs off, which
answered my original question about the slow closing.

Its clear to me now that there is to much wrong with the car for
anything to be clear to me now.

The sluggish throttle feel could just be a result of the massive air
leaks that the intake tube had. The throttle cable adjustment may be
all it needs as far as the throttle body itself goes.

I am going to have to address every known issue and see where that
puts me. I am hoping it warms up outside enough to allow me to go out
and work on it this morning. My Alaskan Husky does not even want to go
outside right now.

Thanks for all the advice so far everyone!