Finally !!

[TVRThomo]

I've been having a few problems with my 94' 4.3 Chim recentely. The car has been running quite rough and cutting out at idle more and more (see previous threads). Replaced all the usuall suspects inc. plugs, leads, coolant temp sensor, lambda sensor etc etc. I have also cleaned the butterfly valve and stepper motor which only made the problem go away for a while !

Anyway it turns out that the problem was under the distributer cap ! When you remove the cap you can see the rotor arm and under that there is like a clear see though cover and directly under that there is a brass type cog with about 5 or so points to it. Three of these points on the cog thingy where full of rust and about three times the size of what they should be, so car was not sparking right ! Since cleaning the rust off and putting it all back together the car runs soooo much smoother and is no longer dumping fuel down the exhaust without burning it off

Anyone know what would have caused this to rust in the first place ?

Thanks in advance.

[Griffter]

TVRThomo said:

5 or so points to it.

Unless you've got the world's only 5 cylinder TVR, I'd hope there are eight of them!! These trigger the hall sensor which switches the amplifier, which switches the coil (which is connected to the leg bone), which gives the spark. It sounds like you had a low or weak spark on 3 cylinders (so you did kind of have a 5 cylinder TVR...). Rust likely caused by condensation over the years as the dizzy isn't watertight, but heats up and cools down a lot.

[That Daddy]

TVRtomo i would see about getting a second hand chopper because if the rust as erroded the tips to excess it will effect the spark duration,try and get a knackered unit & just swap out chopper from that one.

[TVRThomo]

That Daddy said:

TVRtomo i would see about getting a second hand chopper because if the rust as erroded the tips to excess it will effect the spark duration,try and get a knackered unit & just swap out chopper from that one.

Thanks for the advise but I think it has cleaned up OK and could see no signs of any perminent damage. Just out of interest though where would I get a new one from and any idea how much it would cost ?

[that daddy]

i doubt you can buy just the part in question,especially due to the age of these dizzy,s now,maybe you could get lucky with a LUCUS agent with old stock maybe.as you said if its ok then its OK.

[SpudMurphy]

Have a look at this on EBAY - no personal experience of this problem but have used them before and found them very helpful. It might sort your problem.


Range Rover Morgan TVR MG Mallory Magnetic Distributor
Breakerless Ignition Including Coil & Ballast resistor.

Contact: email is: [e-mail]
We will endeavour to reply to emails within 24 hours. Hours of business 9-5 Monday to Friday.

Our Vat number is 373 2330 72

RPi Engineering International Ltd.
Wayside Garage,
Holt Road,
Horsford.
Norwich.
NR10 3EE