Search found 919 matches

by MarekH
Fri Oct 23, 2020 7:04 am
Forum: Technical
Topic: electrical wiring
Replies: 7
Views: 375
Great Britain

Re: electrical wiring

Make a loop all of the way from the battery positive terminal, through the coil and back to the battery negative terminal. This is why it is called an electrical circuit.

Typically, the circuit will go through the ignition switch, a relay, a ballast resistor as part of that loop.

kind regards
Marek
by MarekH
Thu Oct 22, 2020 8:01 am
Forum: Series 3
Topic: Petrol smell
Replies: 2
Views: 172
Great Britain

Re: Petrol smell

Two lines of attack:- Firstly, a non-vented cap is only consistent with the petrol vapours being recycled into the charcoal canister and into the carburettors. See the tan coloured owners manual for how that system works and the Parts Manual for how it is plumped in. Otherwise a vented cap is needed...
by MarekH
Sun Oct 11, 2020 9:11 am
Forum: Series 3
Topic: Hi Torque starter motor
Replies: 16
Views: 466
Great Britain

Re: Hi Torque starter motor

My conclusion is that paying any money for "upgrade" is definitely a total waste if you are going down the EFI route and really only worth it, if the previous Lucas item is in need of repair and fitting the new gear reduction item costs the same as the old one does to put right for the carburettored...
by MarekH
Sat Oct 10, 2020 1:32 pm
Forum: Series 3
Topic: Hi Torque starter motor
Replies: 16
Views: 466
Great Britain

Re: Hi Torque starter motor

Why do you think it is an upgrade? Charlie Chaplin used to start his cars with just a crank handle in his films and he never seemed to have a problem with it.

The lightness makes it easier to hold and manoeuvre as you fit it - it has no bearing on its ability to start the car.

kind regards
Marek
by MarekH
Sat Oct 10, 2020 1:27 pm
Forum: Series 1
Topic: S1 (4.2) vs S3
Replies: 15
Views: 522
Great Britain

Re: S1 (4.2) vs S3

Rather than consider power (and at redline rpm for that matter), you should consider available torque (at medium rpms) instead. At this point, people may wade in showing you a line on a graph of torque vs rpm - which is what people purchase when they go to a dyno. What you want to see is a graph of ...
by MarekH
Wed Oct 07, 2020 7:21 am
Forum: Series 3
Topic: Both speedometer & odometer not working
Replies: 5
Views: 415
Great Britain

Re: Both speedometer & odometer not working

You mean the right angled little gearbox mounted on to the back of the speedometer itself, I presume. Check that the speedo turns freely without this fitted. You can check the right angled little gearbox itself with a small screwdriver or square rod. It should turn 1:1 one way and possibly the other...
by MarekH
Mon Oct 05, 2020 2:11 pm
Forum: General
Topic: Stoneleigh spares day
Replies: 8
Views: 651
Great Britain

Re: Stoneleigh spares day

Dear Christopher, That depends on the individual. John Salway used to run a bi-weekly auction on Saturday mornings at a venue local to me in Godalming. One day I bought something I couldn't carry home and explained that I didn't have a car. Despite the fact that it was nothing to do with him, he dro...
by MarekH
Sat Sep 19, 2020 7:52 am
Forum: General
Topic: Question about OTS 1961
Replies: 9
Views: 487
Great Britain

Re: Question about OTS 1961

It doesn't look like a particularly happy situation.

On one hand, someone bought a car at Silverstone and five weeks later, they now don't want it, or five weeks after Silverstone, a car on offer then is still on offer now.

kind regards
Marek
by MarekH
Fri Sep 18, 2020 7:13 pm
Forum: Technical
Topic: S3 Rev counter
Replies: 6
Views: 390
Great Britain

Re: S3 Rev counter

Yes, if you have a second amplifier for the other bank, otherwise just use a 6 cylinder tacho instead a 12 cylinder tacho.

kind regards
Marek
by MarekH
Sun Sep 13, 2020 11:27 am
Forum: Technical
Topic: S3 Rev counter
Replies: 6
Views: 390
Great Britain

Re: S3 Rev counter

Yes. Mine operates from a simple 12v square wave signal from the Megasquirt. The s3 tacho has a 4k3 resistor to earth and a 4k7 resistor on its input into the chip that interfaces with the tacho needle, so it looks to me like that is a potential divider which drops its coil signal down to about 5v a...
by MarekH
Sun Sep 13, 2020 7:58 am
Forum: Technical
Topic: Kill Switch. S3 fuel pump.
Replies: 7
Views: 276
Great Britain

Re: Kill Switch. S3 fuel pump.

There is no need to hack the loom. The ignition switch fed thick white wire which goes along the right hand side of the car has a bullet connector in to the dash harness tucked into the very right hand corner under the dash. You can intercept it there to fit your toggle switch or to fit an ignition ...
by MarekH
Fri Sep 11, 2020 7:32 pm
Forum: Technical
Topic: New Developments In Rear Crank Sealing
Replies: 9
Views: 829
Great Britain

Re: New Developments In Rear Crank Sealing

Why didn't you use a razor blade Rory and superglue it back together? Indeed if the seal is simply too fat to stretch over the flange, but a wafer thin seal would stretch over , why not just put loads of radial cuts onto the outer face of the seal, leaving the contact face unaltered? kind regards Ma...
by MarekH
Wed Sep 09, 2020 6:07 pm
Forum: Series 3
Topic: A tuning question
Replies: 20
Views: 902
Great Britain

Re: A tuning question

You can spray propane at it (from a plumber's torch - unlit...). If there is a vacuum leak, the car should run richer. (Spray it down the carburettor throat to get an idea of what effect it'd have.) I'd suggest perhaps (one of) the throttle plates is/are sticky and jump back or the choke erroneously...
by MarekH
Wed Sep 09, 2020 7:16 am
Forum: Series 3
Topic: A tuning question
Replies: 20
Views: 902
Great Britain

Re: A tuning question

Dear Simon, From your initial description, you are saying that blipping the throttle means it doesn't settle back to fully closed but instead to the same place it started at. You've set the linkages etc to reflect this, so when it does eventually jump back to where it ought to be, the revs are lower...
by MarekH
Tue Sep 08, 2020 8:21 am
Forum: Series 3
Topic: A tuning question
Replies: 20
Views: 902
Great Britain

Re: A tuning question

The various vacuum connections are documented in the 1974 Parts Manual. Their function is documented in the US edition of the tan coloured Owners Manual (the UK version being blue). A summary is contained at http://www.jag-lovers.org/snaps/snap_view.php3?id=1190800376 where I have annotated the Part...
by MarekH
Thu Sep 03, 2020 6:37 pm
Forum: Technical
Topic: Series 3 fails to start
Replies: 14
Views: 761
Great Britain

Re: Series 3 fails to start

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 t...
by MarekH
Tue Sep 01, 2020 6:53 pm
Forum: Technical
Topic: Series 3 fails to start
Replies: 14
Views: 761
Great Britain

Re: Series 3 fails to start

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
by MarekH
Tue Sep 01, 2020 3:17 pm
Forum: Technical
Topic: Series 3 fails to start
Replies: 14
Views: 761
Great Britain

Re: Series 3 fails to start

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...
by MarekH
Tue Sep 01, 2020 3:16 pm
Forum: Technical
Topic: Series 3 fails to start
Replies: 14
Views: 761
Great Britain

Re: Series 3 fails to start

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...
by MarekH
Sun Aug 30, 2020 6:12 pm
Forum: Series 3
Topic: Alternator overcharging at 18.5 volts
Replies: 4
Views: 242
Great Britain

Re: Alternator overcharging at 18.5 volts

Dear Mike, You should at least attempt to isolate where the problem is before spending money first. The last time someone came on to this forum with the same problem, it turned out that the electrical connector was corroded and broken, so it under reported the battery voltage back to the regulator, ...