Rotor arm hitting Distributor cap pins.

RogerD · Post by **RogerD** » Wed Oct 01, 2014 6:15 pm

I've got a Westfield V8 which I had a little issue with recently. It would splutter at 5.5k and was down on power (normally revs cleanly to 6k) . I cleaned the plugs and noticed one of the plug leads was virtually off. Plugged it back in and was back to full power and full revs.

Recently I installed a gear change light, which connects to the "-" terminal of the coil. I then forgot about this. Mor eon this later.

I then noticed that I was spluttering at 5k (not even 5.5k), although lower rev power felt about right.

All leads were in place and secure. All pipes read around the same temperatue at idle.

I looked inside the dizzy and the pins had severe grooving in them. So I ordered a cap, rotor arm, and leads as a kit off ebay.

Installed them just now and fired her up. Immediately noticed I could hear tapping from the dizzy that climbed with revs. Drove round the block. Really down on power, some backfiring, and smells of unburnt fuel.

Open dizzy and pins are worn exactly the same as my oroginal dizzy cap. Clearly the rotor is hitting the pins. No idea why.

I've also noticed a small crack in the clear plastic inside the dizzy.

Tomorrow I'm going to put back on all the original parts (dizzy cap, rotor and leads) and see if I can at least get back to a smooth running car up to 5k.

Im also going to disconnect the cable from my gear change indicator from the coil - I can't imagine this is the culprit but it's the last thing I changed before the rough running.

Why had my rotor arm been hitting the old dizzy cap, and also the new one?

Any tips greatly welcome. I want my clean 6k of mad power back!

DEVONMAN · Post by **DEVONMAN** » Wed Oct 01, 2014 8:07 pm

Is there any sideways play in the dizzy shaft.?

RogerD · Post by **RogerD** » Wed Oct 01, 2014 8:56 pm

Not really, All feels fairly tight. (when I try to wiggle the rotor arm).

JSF55 · Post by **JSF55** » Thu Oct 02, 2014 7:55 am

I'm pretty sure that's the wrong rotor arm for a blue cap ? one of the others might know more, not seen a rover dizzy for years

DaveEFI · Post by **DaveEFI** » Thu Oct 02, 2014 9:20 am

Looks similar to one I have here - apart from the colour.

I'd say either the shaft or the cap is off centre.

Be easy enough to check run-out on the rotor arm with the dizzy out of the car, but checking the cap would be more difficult.

Denis247 · Post by **Denis247** » Thu Oct 02, 2014 4:58 pm

If it's hitting ALL the posts, and you're sure that it IS hitting them, and there's no play, why not just shave a bit off the end of the arm?

mgbv8 · Post by **mgbv8** » Sun Nov 16, 2014 9:47 pm

Denis247 wrote:If it's hitting ALL the posts, and you're sure that it IS hitting them, and there's no play, why not just shave a bit off the end of the arm?

Ditto !!

RogerD · Post by **RogerD** » Sun Nov 23, 2014 11:55 am

It's hitting half of them - so a concentric issue of some sort. She's all running good now after I found my problem was a failing cable in the alternator.

When the dizzy starts to give me grief I'm going to convert the engine to a megajolt DIS system - but I'll leave it for now as I dont' like fixing things that already work....