Hi,

My XJ6 has sat in the garage, covered up for the last 3 years.

After cleaning/regapping plugs, filling su float chamber up with fresh fuel (the fuel in the tanks has gone orange-ish), stopped the float from sticking! a fresh battery and topping up the dash pots, she fired up! But runs very rough and blows a lot of black smoke.

I'm not very mechanically minded so I had a few basic question I'm hoping someone could help me out with:

(FYI the car is a 74 XJ6L S2, with 4.2ltr twin SU engine.)

1. If the fuel switch is out (not pushed in) does that mean the passenger side tank is in use?

2. Do the tanks share fuel at all? I'm thinking just siphoning one of the tanks and putting fresh fuel in (and getting to the second tank at a later date, as it's tricky to dispose of fuel where I live). Also I plan on siphoning using a hand siphon, do the tanks have any filters stopping me from putting a hose down the tank?

3. I cleaned the plugs (they looked like this originally - http://i8.photobucket.com/albums/a16/king_nero/01-1.jpg )

But due to the fact it's running pretty rough, and the leads are pretty new (well....a few years old now, but were pretty new before put in storage) is it just worthwhile replacing plugs? (should i really do leads as well?).

4. Is it worthwhile rebuilding the carbs or replacing a common part on them if they've been sitting a while?

Any advice would be greatly appreciated.

Many Thanks,
Dan

 

Dan, well done, it is at least running.

I will go thru in # order so I dont get confused.

1) Memory (HAHA), the switch OUT is RH tank, There is even a SMALL "R" on the side slide part of that switch that says it, if your eyes are good enough to see it.

2) Under "normal" situations, NO.

3) Mmm, overfueling a tad. Does this thing have an "electric choke", as in a 3rd carby thingy between the 2 main SU'S. If so, that is a major PITA at any time, hence the conversion of most to manual choke. That has been MANY years since I did one, not hard, very fiddly, and some serious "outside of box thinking" required.

4) Depends on the model of SU. If HD8 then YES, the notorious main jet diaphragm. If HS8, then a GOOD clean, mainly piston and bellchamber, should suffice.

OH, no more numbers.

In NSW contact SU Midel (I thinks that is still their name) on 02 97595598, and they are HELPFUL, and in Miranda I think, or close by.

Ask away if you need some more info.

 

Hi Grant,

Firstly thanks for the quick reply!

Well I'm glad I asked about the fuel tank! Will see what my eyes can make out during the day tomorrow.

I just went and took a couple of photos as I wasn't sure, but I think I'm confident in saying there's no electric choke. There is however, definitely a manual one, that was replaced a long long time ago, but still works fine. I used this to initially start the car, but interestingly I shut this off pretty quickly and it still continued to smoke and run rough.

Some pics:




I think (from searching around) I have the HS8 carbs. Does that sound right based on the pics? I'm reading "HS means a 'side' float chamber" If that's the case I'll look into cleaning them up!

Another question while I think of it .....I'm hoping to clean the engine bay up a bit and wondered if I can safely remove this this black metal part that runs over the top of the motor ( i think this is part of the AED? ) and doesn't appear to be hooked up to anything...



I'll have to update my details, I'm now back in QLD (redland bay). If you know of any good Jag mechanics up here I'd love to store a few names and numbers away for any future work.

Thanks again,
Dan

 

Dan,

Look like HS8 to me. Reach under the carb, and if you feel a plastic type hose from the bottom of the bowl TO the jet, you got HS8.

NO electric choke, good.

That hot air duct can go in the recycle bin.

Check out the QLD section of the Australian area, and locate Clarke (01xjr). he is the co-ordinator up your way, and has just done the carbs on his S1, HS8, and did a write up, which is in the stickies of this section here.

These engines do not need much choke.

The mixture screws are probably all messed up, and the pistons are more than likely jammed in the bellchambers, but all that is spelled out real well in that stickie.

 

Brilliant, thanks!

Cheers,
Dan

 

Hi Dan, the HS8's is a job I have recently completed and it made a huge difference. It stopped the rough idle,stopped the black stipes of carbon on my garage floor and black smoke,and cut my fuel from 21L/100km to 17L/100km.
I was new to Jags and Grant (above) and Ken,your NSW coordinator talked me through the process and I added pictures
If you need new set idle and mixture screws send me PM with your address and I will post you new set as I .(I got 5 sets from the uk for less than one screw in Brisbane). I will never use another 4 sets in a lifetime. You will have them by Wdnesday.

https://www.jaguarforums.com/forum/a...setting-up-pdf

https://www.jaguarforums.com/forum/a...-refitting-pdf

Cheers

 

Hi Clarke,

I was just trying to look up your carby post

Thanks a bunch, I'll take a look over these pdf's. I've not worked on a lot of cars before, and no jags, so this is all a little new to me! But i'm enjoying uncovering the most beautifully engineer pieces in this car....very satisfying to work on what I consider a piece of art.

I'll let you know RE the mixture screws (thx for the offer, very kind!).

Cheers,
Dan