Sunday, September 23, 2012

Gas Guzzler!

The old girl has been consuming fuel at quite a high rate since we got her. I recently did some calculations and it was worse than I thought, she's drawing fuel faster than our old Rolls-Royce Silver Shadow with its 6¾ litre V8! The Mark VII's six cylinder engine is only a 3½ litre! The Jaguar's fuel consumption is 19.5 litres per 100 km (12 mpg) averaged over four refuels. The Rolls-Royce averaged 18.9 litres per 100 km (12.5 mpg) over the same period of time.

We are about to do a couple of long trips in the Jaguar, one to the Hunter Valley (245 km / 150 mi) and to Parkes (260 km / 160 mi) so I though it a good time to check the tuning to see what's amiss. Was it running rich? What was the ignition system like?

I started by removing the spark plugs. They were quite sooty for what appear to be fairly new plugs - so I gave them a clean up, re-gapped them as they appear to have not been set to the required 0.022" from new, and re-installed them.

I then checked the points gap, they appeared to be on the required 0.012". They are in a crappy spot to work on, I've been spoilt in the past, Morris Minor distributors are in a very convenient location, even more so on the lovely side valve engine. The Rolls-Royce was typically easy V8 affair.

Then I proceeded to check the ignition timing. It was perfectly set to 5°, unfortunately it had been set to after TDC, not before! And the last tune was performed by a "qualified" mechanic! Lucky us mere amateurs are on the case. As soon as I started advancing the timing, the engine ran quieter and idled smother. I think the strange exhaust sound I was hearing was actually late combustion occurring in the exhaust port. I set the timing to around 7° BTDC and took the old girl for a 20 km drive. She seems to pull better and has more low end torque.

I checked the mixture of the front carburettor, if anything it was a little lean - not rich. I will leave adjusting the carburettors for another time.

I will be interested in checking the petrol consumption now I have fixed the ignition timing.

Coming next....... well erect trafficators! :-o

Wednesday, September 12, 2012

"Penetrene" to the rescue!

The steering column in the Mark VII Jaguar is adjustable for reach but our steering column was stuck in the fully extended position. The adjustment locking screw collar around the steering column was seized and no amount of brute force was going to shift it, I even tried with some multi-grips but it still wouldn't budge. I guess it's been this way for a while because I could see where someone else had swung off the locking collar and had slightly damaged it.

So I sprayed some Penetrene down inside the screw collar a few days ago, tied a rag around it and left it. I wasn't sure if it would work.

Tonight I was looking at the Manette Control problem when I thought I'd have a crack at the adjusting collar and blow me down it moved with the multi grips!

Even more pleasing, now that I can shorten the length of the steering column, the tube on the manette control is now locating in the stator tube as it should and the manette control has stopped spinning with the steering wheel! Happy days.

While I was fiddling with the steering column I corrected the wheel straight ahead position following yesterday's wheel alignment.

Getting the circlip off the end of the steering column was a pain in the arse, I faffed around for ages with my circlip pliers trying to get it off - ended up using a couple of screwdrivers and it eventually came off. So much for using the right tool for the job!

The wheel is now correctly oriented at the straight ahead position, the manette control stays straight and the trafficators automatically cancel! Good stuff.

Now I just have to fix the lazy trafficators!

Tuesday, September 11, 2012

Manette Control

What the heck is a Manette Control?

According to the Jaguar Factory Service Manual, that's the name for the control in the centre of the steering wheel with the horn button and trafficator control.

Unlike a conventional car horn button, the manette control does not spin with the steering wheel - it stays pointing straight ahead. Well it's supposed to anyway. This is not the case in our Mark Seven.

The manette control in our car spins with the streering wheel which is a pain in the arse when trying to activate the trafficators and it also defeats the self cancelling mechanism.

The control is held static by a "stator tube" that runs down inside the steering column, with the wires for the electric controls running within this tube. From what I can work out from the factory manual, the manette control has a short shaft (not sure exactly how long) that then interfaces with the main stator tube. I think it's this interface between the two tubes that is faulty in our vehicle, the join must be worn out allowing the control shaft to spin within the stator tube.

So I have to tackle this job. What I plan to do is disconnect the harness that comes out of the centre of the steering column at the steering box, attached a draw wire to it and pull the manette control out to inspect the end of the tube where it interfaces with the stator tube to see what repair work is needed. I hope it's this end and not the end of the stator tube that needs rework - the stator tube appears to be more difficult to remove.

I'd love to hear from any other classic car owners who may have tackled this problem.

Wheel Alignment

Odo: 15,907 miles

Took the Jaguar for a wheel alignment today. The steering was twitchy and the tyres squealed in faster corners.

The folk at Lithgow Tyre Service did a great job. They have been great to deal with, did a great job on our Holden SS recently.

Apparently the toe adjustment was miles out, -8.9 mm instead of the required 4 mm. -13 mm out! No wonder the steering was acting up.

She steers beautifully now, a bit of free play in the system as can be expected for a 60 year old vehicle, but the overall improvement is great.

I have to pop the steering wheel off the shaft and correct the straight ahead position. I will do this along with fixing the manette control (see separate post).

Monday, September 10, 2012

Nice photo opportunity

Went for a five minute drive on Sunday arvo. This photo came out great.

Saturday, September 8, 2012

Run to Blackheath

After a night of intense wind, we awoke to a house with no electricity. So we lit the fire to warm the house, ran the generator for a few hours so we could get showered and ready and then headed off for a drive in the Jaguar to Mount Victoria to vote in the council election. Then we headed to Blackheath for a lovely picnic in the sun. The Jaguar performed flawlessly.

Sunday, September 2, 2012

New Shock Absorbers

Fitted new Koni Classic adjustable shock absorbers (82-1027 front and 82-1081 rear) to front and rear due to harsh ride. Front shocks were dated 1958! Rears were Monroe Gas, hence the harsh ride. Koni shocks set to softest settings. Tremendous improvement in ride quality.

Adjusted front suspension ride height as front end appeared too high for my liking. Right side was more difficult to adjust due to adjuster located close to brake booster and guarding. Front left currently sits slightly lower than front right. Need to revisit and correct before wheel alignment.

Saturday, September 1, 2012

Carburettor Float Valve Sticking

Much fuel leaked under engine when ignition was left on for a short while. Traced fault to front carburettor float valve sticking in down position as the float arm had worn and was not contacting lower travel stop correctly, allowing the valve to fall lower than it should therefore snagging float arm in down position. Initial leak from float bowl overflow pipe, then from starting carburettor. Took a couple of goes to properly rectify problem (had to smooth wear from float arm and also re-shape float arm so it would engage on lower travel limit peg on float bowl upper assembly. Checked rear carburettor float action - fault not evident, lower travel stop works. Cleaned both float bowl inlet filters (front one contained a fair amount of crap). Took a couple of goes to get fuel supply banjo fitting washers to seal correctly. Had to smooth fibre washers flat on emery paper as they had worn and were hard. Need to replace washers soon.