Engine not revving. Now running fine

[64etype]

ETTony : it is not the vacuum advance which you need to worry about . It is the MECHANICAL advance mechanism which may be seized i.e. the bob weights attached to the central spindle . The first check you can make - without removing the distributor from the car - is to take hold of the distributor spindle and see that you can twist it against spring pressure , and that it springs back after you have done so. If it does not do this , then on the face of it the advance mechanism is seized. Even if it does spring back, you still need to check that it advances as the rpm rise, and you can only do this with a timing light

In the case I described in post #63, it was the vacuum advance that was causing the problem. The canister was "pulling", but the plate it was attached to was not returning to it's static position when the vacuum signal was removed. Further, it would stick at different advance positions. So, the static setting at the crank was a moving target. Removed, cleaned and lubed the bearing surface between the two plates and the problem was resolved.

[chrisfell]

Just a thought, as I think you said you'd found the ignition timing was out as a result of the non original timing marker, were the cams timed to the same marker at the same time and therefore out by whatever the ignition was out?

[ETTony]

Chris,
The cams confirmed my new measured timing marks.
So with engine at 'my' TDC the cams also were at their marks.

I have had my Alternator seen too by Burghfieldalternators, swift turn around. Problem was dry solder joints.
(Still not charging )
Also removed the oil filter housing and renewed the relief v/v and spring and cleaned the ballance v/v.
My oil pressure it a lot healthier now.

Looks like a dry day tomorrow, so out for a run.
Then remove and check distributor.

[ETTony]

Had a peek inside my distributor, looks good. The centrifuge advance weights are free, lightly greased and seem fine. The vac advance works fine too. Strobe shows it working correctly. So that is another item ticked off.
Though I am struggling to explain my timing conumdrum.

Alternator. I am missreading the situation.
I do not see the voltmeter at say 14volts after starting.
But after a good run out today I checked the battery with my meter and see it is still fully charged.
Guess as my battery is new, it is not depleted significantly, so not a big drawdown from the alt. So not much to see on my voltmeter. Fretting about nothing.

Lastly. After refreshing my oil filter housing relief v/v and ballance v/v, I now have very good cold and hot pressures, I see the engine coolant is running cooler too.

I plan to keep out from under the car for a while now and drive it.I will get it over to the Jag guru later.

Next topic is the LM24hr, heading over with mates on our bikes for a week of fun.

Thanks for you ideas, suggestions and guidance guys.
Tony

[Hugo]

You should still see 14 volts on the gauge, new battery or not. The gauges are not always accurate though. When you say your battery is fully charged, what reading are you getting? There's not much difference in voltage between a fully charged and half charged battery - maybe half a volt if I recall.

[ETTony]

My alternator was repaired this last week.

Before startup, voltmeter 12v, battery with meter 12.5v
Tick over voltmeter 12v, battery 12.5v
After a good run battery showing 12.6v or there abouts.
On a run voltmeter maybe showed 12v

This is why i thought i had a problem. But in practice, it appears OK.
I am not going to trickle charge the battery, which i had been doing before the repair.
The jury is still out on this.

Thanks for your input Hugo

[christopher storey]

A no-load voltage of 12.5 or 12.6 is on the low side. Normally I would expect 13.2 to 13.6 at the end of a period of charge after a 1 hour period of rest . On the other hand, modern technology ( calcium etc) batteries do not always behave quite as Leclanche cells did, so I would not worry about it, but keep an eye on it over a period of start/charge cycles

[Hugo]

I have seen some perfectly sound batteries give a surprisingly low voltage reading at rest. Under 12 volts sometimes. According to the meter they should be scrap, but they still work just fine. I've seen that a few times.

[JagWaugh]

I have seen some perfectly sound batteries give a surprisingly low voltage reading at rest. Under 12 volts sometimes. According to the meter they should be scrap, but they still work just fine. I've seen that a few times.

Yes, same here. The thing is when something else goes marginal (like the alternator, or an earth) a whole host of other symptoms will manifest themselves rather quickly, and this can lead to changing all kinds of other parts in an effort to resolve the secondary issues without ever noticing that the problem lies elsewhere.

[ETTony]

Time for an update on my engine.
After fettling by a local Jag guru, the engine is purring.
Adjustment to my timing and then set up the carbs correctly c/w new UM needles.
Enjoying the fine weather.
Thanks for your help guys.
The jobs left are more technical and not just nuts and bolts jobs.

[Hugo]

Really? This started off as an engine that would not rev past 1,800 rpm. And that was due to nothing more than timing and carb needles? Frankly I would not have thought that was possible.

[chrisfell]

Really? This started off as an engine that would not rev past 1,800 rpm. And that was due to nothing more than timing and carb needles? Frankly I would not have thought that was possible.

I've known this to happen on other engines. I witnessed this on a friend's Bonneville. He'd accidentally set the static timing to after TDC. The engine started easily and ticked over at just a few hundred RPM, but had no power and wouldn't rev at all.

[Hugo]

It just seems a very dramatic result from a couple of minor tweaks. I would have expected the thing to barely run if it was that bad, but I believe it was running normally up to 1,800 rpm. I haven't gone back over all the posts though.

[ETTony]

It just seems a very dramatic result from a couple of minor tweaks. I would have expected the thing to barely run if it was that bad, but I believe it was running normally up to 1,800 rpm. I haven't gone back over all the posts though.

The timing marks on the damper were not correct, so I started off on a wild goose chase.
After determining the true TDC and installing the XJ6 pointer, my timing was better and car starting to rev more.
My guru did the rest.

[mgcjag]

Hi Tony.....did you also reset the cam timing as going back a few pages these were not spot on

[ETTony]

Hi Tony.....did you also reset the cam timing as going back a few pages these were not spot on

The cam marks were checked against the correct TDC, all fine there.