i just got my timing set and now my engine is idling around 2300rpm and i cant figuure out how to drop timing down to about 750 becuase the throttles are completly closed

 

You've got air coming in from *somewhere*. Is this a V12? Do you have the air filter housings off, by chance? If so, air is being sucked in thru the empty bolt holes.

If not that look around for a big vacuum leak

Cheers
DD

 

i found a vacuum leak under the passenger side intake, a big one and i dont think my AAV is working correctly but im going to mess with that today to because that is supposed to be where you adjust the idle.
and i have an 87 xjs with a v12 and filter housings on.

 

also, i found out thst my plugs were very carbon fouled and it wouldnt idle smooth untill i ripped it up my street at about 80

 

i hope thats MPH and not KPH, because honestly, with the way mines been running, i cant envision these as fast cars.

 

You'll want to redo all the vac lines on the pass. side. You can't see 90% of them, and when I pulled mine out they were in horrible shape - paper thin, rotten and extremely soft. My vac regulator was making a honking noise because the vac line feeding it was "breathing" - it was so thin and soft as soon as the vacuum would build it would suck shut then it would release itself somehow (maybe it sucked open a larger hole? dunno) so it was making this rhythmic honking noise.

Redo EVERYTHING under that passenger's manifold. My car ran a lot better when I did. This should be a very high priority for anyone buying a new XJ-S, from an emissions and a drivability standpoint.

D

 

i second this. all my vacuum lines were fine, but they were all disconnected and i had no idea where any of them went!

 

How did you find out where they all went? I would like to do the same.

 

The Jaguar service and parts manuals have excellent illustrations of the vacuum hose routings.

For $30-$40 you can get Jaguar CD that has the XJS service manuals, electrical guides, parts catalogs

Cheers
DD

 

I've eliminated mine to the basics, but there is one I'm still not sure where I should go with it. The vac-advance to the distributor! I know it isn't supposed to have constant vacuum to it, but where can you go for that? Between the air cleaner and the butterfly?

 

My '88 had vacuum nipples on both the top side and underside of the throttle bodies. The top was constant manifold vacuum, the bottom was ported vacuum (or maybe that should be vice-versa). Anyhow, it shouldn't be hard to tell with the engine running.

Cheers
DD

 

Mine goes from the nipple underneath the A bank throttle. Works a treat and all the other stuff removed.
Greg

 

For reasons I can't recall you're not supposed to send more than 11"Hg vacuum to the vac advance, which is why they had it on that orange vacuum regualtor hanging under the pass. manifold. Kirby mentions in his book that he once removed all that junk, and then ended up putting it back on. File that one away for later...

 

m90 yes thats mph, because i was being followed in my friends f150 because my speedomoter wont work so he needed to estamte my speed. first world problems with expensive transmission swaps. yanno

i two eliminated everything but the vacuum advance, which i neatly mounted right up at the front all next to eachother and convient, pics when i get home. i believe the line should go underneith because that is affected by the throttle? i dont remember how i set it up but i used the diagrams.