Series 3 fails to start

[44DHR]

Just trying to help a friend with an immaculate Series 3 E Type which was last run a couple of weeks ago, but now refuses to start.
The engine turns over, but the SU double action fuel pump continues to tick. Is this correct ?
Any thoughts on what the issue could be ?
Regards,
Dave

[MarekH]

On an unmodified car, that is correct and will not be part of the issue. The v12 has a fuel one way valve and return line on the left hand side of the engine.

Have a look at the spark plugs to see whether they are wet.
Put the (still connected) plugs on the manifold to earth them and see whether you have a spark.

kind regards
Marek

[MarekH]

On an unmodified car, that is correct and will not be part of the issue. The v12 has a fuel one way valve and return line on the left hand side of the engine.

Have a look at the spark plugs to see whether they are wet.
Put the (still connected) plugs on the manifold to earth them and see whether you have a spark.

kind regards
Marek

[SESH]

It's correct for a series 3 pump to keep pumping. The fuel goes via a return valve which returns unused fuel back to the tank. There is a constant flow of fuel.
Can't help with the non starting issue, have you checked fuel delivery and spark?
Mike

[44DHR]

Many thanks for the prompt response.
My friend has confirmed that the pump is returning fuel to the tank, so perhaps we are looking at some form of ignition issue.
He will pull one of the plugs and see if he has a spark. I don’t know much about the V12 ignition system and potential faults, but I did suggest he does the basics and check the main coil lead to the distributor to see nothing has come loose. Also to turn it over tonight when it is dark to see if any shorting is going on on any leads.
Just seems odd that the car was running, was driven into the garage and now fails to start. The starter motor is turning the engine over ok. Could the starter switch cause any issues with mobilising the ignition ?
Regards,
Dave

[MarekH]

No, it can't, because the ignition comes through the white/blue wire unballasted during cranking. This has nothing to do with the ignition switch and is in parallel from the starter motor relay.

Stop clutching at straws and look at the plugs.

kind regards
Marek

[44DHR]

New coil now fitted, but still no spark.
I guess he should be looking at the amplifier. I know nothing about the Opus ignition system, but heard it can give issues.
Regards,
Dave

[PeterCrespin]

If he still has the original it is not a case of 'if' but 'when'. In my case it started heavily misfiring in a long two-lane no-escape Swiss rock tunnel approaching rush hour, with a huge Scania tailgating my top-down OTS. Did I feel vulnerable? Just a bit!

[cactusman]

Quite a good explanation of how the Opus system works...

http://www.jagweb.com/aj6eng/ignition.php

It was never the most reliable system partly due to where the mounted the module...right in the V at the top of the engine where the electronics got cooked.

If it has fuel then it is almost certainly ignition and suspicion immediately falls on the Opus module I'm afraid.

[MarekH]

I think people are often a little unfair in their assessment of the OPUS - how many of you still have any electrical equipment from before 1975 operating in their homes?

Firstly, I'd check out the wiring and connectors. We know it was running a week ago, so I'd trace the wiring diagram from the c2 to c4 contact on the starter relay then through the wiring to the ballast. Then I'd check the ballast resistor to see (r2 and) r3 are the correct resistance. All of this is free to check and details are in the big blue Repair and Operation Manual.

When I purchased my car, the previous owner used to always swear by using a big powerpack starter to get it running. Closer inspection showed that the wiring to the ballast had perished somewhat and was literally hanging on by a few slender copper threads.

Given that the r3 ballast resistance and coil are both at or under 1ohm in value, any poor wiring or connectors will have a significant effect on performance. If you have a high resistance in the path, then not much current flows and so the coil, new or old, doesn't charge.

If that checks out, then consider triggering the coil, e.g. by temporarily swapping in a spare OPUS unit.

kind regards
Marek

[cactusman]

I tend to agree Marek....Lucas is not as bad as many make out...although the OPUS system has gained a reputation for unreliability that goes back a while....I suspect mostly due to where Jaguar decided to put the electronics....semiconductor electronics likes being cool and Jaguar chose almost the hottest part of the engine Had they sited it better it may have given less trouble....certainly though....before condemning the module check the ballast resistors And connections.
And I have more than one Tek oscilloscope from the 1950's/60's - one predates all e types!....that are in rude health.....but at the time Tektronix built far and away the best scopes in the world and, in my view, some of the best built electronics ever made....they came with a "lifetime" guarantee and Tek went to enormous lengths to ensure they lasted The same cannot be said of anything electronic today....

[44DHR]

Many thanks guys for all your support to my friend.
We really appreciate all your suggestions and advice.
Regards,
Dave

[Norton]

Hi. I have read about repositioning the ignition unit to a cooler place. But then longer wires will be needed. Does anyone know if I can cut the wires and solder in an extension? Or will that upset the electronics in any way? -71 S3 with ignition unit in original ( hot ) position.
Harald

[SESH]

Hi Harald,
I have the replacement non-Opus distributor and amplifier from SNG Barratt.
Plus I relocated the amplifier from the centre of the V of the engine to the picture frame, just below the header tank. However, remember to request the longer wires to allow it to be mounted further forward and once it's mounted on the picture frame ensure a dedicated earth from one of the bolts. I bought an extra header tank bracket to use to mount the amplifier onto the picture frame.
Can't help with splicing in some additional wiring, mine had an extra long wiring supplied with the amplifier by SNG (as a special request).
Mike

[Norton]

Hi Mike. Thanks for advice, maybe a replacement is best option. I was thinking of a relocation of amplifier as a recaution before it fries..
Rgds Harals