tacho faulty after coil change

[frogeyeman]

Hi,first time on.Changed the coil on my series 2 e type for a red Accu one.On first drive had misfire and tacho not going above 2,000 revs.Put old coil back on and engine now running fine but tacho still same problem.Any ideas why the tacho went faulty.Running Lumenition ignition system.Anybody got a spare tacho?

[piman]

Hello Frogeyeman,

isn't your tachometer the usual Jaguar one driven by a generator of the rear of the camshaft?

If so the first job is to check the drive tag is not badly worn and slipping?

Alec

[e600]

Its a series 2, therefore the coil drives the rev counter. I guess you have a ballast resistor type coil being series 2, just check your replacement coil is the correct voltage.

Regards
Pat

[piman]

Hello Frogeyeman,

what type of tachometer is it, if Smiths either RVI or RVC, the designation should be on the face of the instrument? RVI can be problematic with Lumenition ignition and their answer is to replace it with an RVC type, or revert to good old fashioned points?

Alec

[frogeyeman]

Hello Frogeyeman,

isn't your tachometer the usual Jaguar one driven by a generator of the rear of the camshaft?

If so the first job is to check the drive tag is not badly worn and slipping?

Alec

thanks for your reply.The rev counter is the later type driven from the impulses from the coil

[frogeyeman]

Its a series 2, therefore the coil drives the rev counter. I guess you have a ballast resistor type coil being series 2, just check your replacement coil is the correct voltage.

Regards
Pat

Thanks for your reply.The car does not have ballast resistor according to wiring diagrams.The original coil is 12v as was the new one

[frogeyeman]

Hello Frogeyeman,

what type of tachometer is it, if Smiths either RVI or RVC, the designation should be on the face of the instrument? RVI can be problematic with Lumenition ignition and their answer is to replace it with an RVC type, or revert to good old fashioned points?

Alec

The rev counter is made by Smiths but will check to see if RVI or RVC.Should have left well alone as it was all working before coil change.