V12 rotor arm

[E-TypeIP]

I posted on here a few month back about my car running fine when cold but back fires and cuts out after about 15 mins. A forum member said there's a good chance it's shit blocking the filter in the fuel tank, however this isn't the case. I have recently changed the coil and the amplifier but e car is still doing the same.

I contacted a friend of mine who builds them, he informed me tha it could be the ROTOR ARM. I have taken the rotor arm off the car and the end plastic is cracked all the way around but the metal bit is fine. Would this be a possible cause for he cars symptoms??

I have also changed dizzy cap, plug leads and new king lead??

[1954Etype]

Chances it is the rotor arm - sounds as though it needs changing anyway. Make sure you buy a good one though - there have been an awful lot of bad copies. I'd go to the distributor doctor as he seems to know his stuff.

[E-TypeIP]

I have sourced one off eBay, I have used the guy in the past and has always sold me decent parts.

I was also wondering, I have a rotor arm that I bought for my V12 SERIES 3 XJ. However, this is blue but looks identical to the one I've taken off. Would this do do you think??

[1954Etype]

Ian, I have no idea . You could just try it?

[PeterCrespin]

There are two types of arm depending on the ignition system used (and different for fuel injection cars too). You can swap them one way (because there are redundant elements that don't cause any issues) but not the other way (which would mean there were aspects missing). Some V12s used a reed switch under the rotor that had a magnet in it IIRC and others had pick-ups of some sort. I'm rusty on V12 stuff and some of it relates to early injection systems anyhow, not E-type. But yes, a dud rotor arm could cause the symptoms.

Be aware, however, that merely cleaning the filter does not by any means imply the fuel system is clear of debris. Start with the sump and work systematically all the way to the float bowls.

Pete