Hey there, I got a 99 xj8. Was wondering if this is normal, there is always a very short pause when you press the gas pedal. It's as if the transmission is very slow and does not engage the gear fast enough. It's like you dont get any gas when you press the pedal for a little bit. I've also thought of adjusting the wire that goes to the throttle body but I'm not sure whether my model is a drive by wire or not.

 

Me too, I shift manually and it is fair but not good , by the way when you turn off the traction control can you spin the tires?

 

Negative, not at all. Whenever I turn traction control off it seems to do absolutely nothing.

I'm starting to think this has something to do with the traction control and is limiting the instantaneous acceleration. It's really funny, when you are at a stop, and press down the pedal all the way, the first 5 seconds are terribly slow. I'm not sure what's going on.

 

sounds like you need to adjust (tighten) the cable from the peddle to the throttle body...make sure it has a cable tie on it...do some searches and you will find the video and step by step for tightening...sounds like that is your problem...

 

It can't hurt (if done right) to tighten the accelerator cable, but make sure you read the instructions and do it correctly. What concerns me is your comment that you think it has something to do with traction control. Are you saying that when you turn traction control off you don't get the lag?

 

I'm sorry for the confusion. I still get the lag when I turn off traction control. It seems that traction control does not work at all. I would expect that with traction control off, and full pedal down you would be spinning around your rear tires at the green light but far from it.

Also when manually revving the engine it still has this slight lag.

 

Tighten the cable and see if that helps. It's easy and painless, so if it works great, if not you didn't spend too much time and NO money on it!

My 03 XJ8 was a bit sluggish before I tightened the cable - now it responds right away. I haven't tried "burnning out" so I don't know if that's going to happen, but at least I don't feel like I have to push the accelerator down 1/4 before I get acceleration. Also, it kicks into low gear (passing gear) without having to floor it.

 

I had always been disappointed in the performance of my 1998 XJ8, I know its heavier but just didn't have the ooomph like my 1997 XK8. I always had my foot in it to stay up with traffic. I did the adjustment and what a world of difference. Haven't tried spinning the tires but I don't have many cars passing me now. By the way someone had played around before (no tie wrap) and 5 turns to get rid of the slack.
Quick easy and it worked.

 

I also had the sluggish in my 98 XJR, even with the cable adjustments, still wasn't producing what it should.

BUT!!

When I cleaned out all the carbon build up under the throttle body, man oh man what a difference. SMOKE tires all day long if I want too and gas mileage is up from 15 highway to 20 highway.

I am in the process of creating a how to, but in the meantime; remove the throttle body from the car. Clean it if it is needed, but thats not where I found the carbon build up.

Set the TB to the side and look down where you just took the TB from, there is a hole towards the firewall, if that is clogged, clean it. Then remove the valve (don't know the name of the part) but you will know what I mean.

Take that valve apart and clean it too, the pipe that leads from the valve to the passenger side exhaust pipe wasn't clogged, but had carbon residue in it, so I clean it anyway.

That hole I am talking about, my was completely CLOGGED, I had to use a flat head screw driver to break it, then scraped the rest off, until it was completely clean.

Total time, about 30 mins to do and that 30 mins was totally worth it.

SGB

 

What are the factors that cause the blockage? Town driving , poor maintenance, bad gas or not blowing out the shut? What are the long term effects of driving with the problem? Can 93 octane gas with fuel addative keep it from coming back?

 

wow! ill be doing this soon, hope it helps, because my xj8 4l are very sluggish from the start,.

i know how 4liters go.. tested my friend xj8, and he spin the tires very easily.. well mine is not.. not even close. (trac off) but later, 50 to 160km/h it's the same as my friends xj8

 

My '99 xj vdp is the same, a pause off idle, I searched for the thread on how to adjust the throttle cable, but so far came up with nothing.
I searched YouTube and found this video. I'll be checking this on my car later today.

 

i have done this yesterday and find out that i had only 70% open, fixed to 100, but throttle response still sluggish

 

Thanks SBG, I'll be looking out for your video/photos for cleaning the throttle body and adjacent areas, can't seem to find the appropriate video on youtube currently for my 98/99 VDP

 

i have cleaned all throttle body, everything is clean, just tested my car and looks like nothing has changed,

also, i have detected that there is no catalyst converter (driver side). other side is okay.

maybe this can be a reason why my acceleration is sluggish?

 

 

 

 

 

Sluggish or hesitant? Hesitation can be the MAF being either dirty, or needing replacement