Rover V8 Starting Problem

Rover V8 Starting Problem

Author
Discussion

Reb Smith

Original Poster:

11 posts

197 months

Monday 12th October 2009
quotequote all
Anyone out there can diagnose my regular ignition problem. I am running a carb'ed 4.6 stage 3 Rover engine in my MGB , all go's well, but i regularly get starting problem and it appears to be the same problem.
I go to start it and nothing, after the useual checks I come to the same place and find that when I open the dizzy I find the rotor arm is blackened, after a little wet and dry paper to get it back to the shiney surface it fires up no problem, works every time.
I have replaced the dizzy cap, rotor arm and ignition leads for new. The dizzy is the original (but standard) Rover SD1 with the remote Amp, so it is around 25 years old, now I know what most of you are thinking but the old adage of 'If it ain't broke dont fix it' is the first commandment in my garage. And although I have been thinking of ditching the distributor and going for coil packs and a crank driven trigger ignition system. But first things first why is my rotor arm getting blackened, and I am not speaking about high milage it has happened 3 times in about 3000 miles.

GreenV8S

30,481 posts

291 months

Monday 12th October 2009
quotequote all
Is the blackening just corrosion on the contacts, or is it something else such as plastic or soot coating the whole area? If it's just corrosion, is there any problem with dampness?

Reb Smith

Original Poster:

11 posts

197 months

Tuesday 13th October 2009
quotequote all
Good question. Not sure what it is, but I though it looked like a carbon/soot type deposit, like there was some type of arcing. The car is garaged all the time and this has happened during hot weather so dampness should not be an issue, This is on the rotor tip which is a non ferrous material so corrosion should not be there.

GreenV8S

30,481 posts

291 months

Tuesday 13th October 2009
quotequote all
Would be worth finding out what that contamination is because it's not normal and may point to the problem, but I wonder if the underlying problem is a weak spark which is OK when the rotor arm is brand shiny new but baulks at a bit of resistance?

Reb Smith

Original Poster:

11 posts

197 months

Wednesday 14th October 2009
quotequote all
Hi
Thanks for this, if it were as a result of resitance where typical y would this come from, the coil or Amp, Plugs are less than 6000 miles.

350zwelgje

1,820 posts

268 months

Tuesday 20th October 2009
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I would try another rotor.
Why? As in the beginning ordered standard replacement parts and first time the rotor didn`t fit, the second didn`t fit either. After this discovered that several types are available with ridges and notches that are different. After some trail and error found the right rotor, but it is a `strange` push fit, as in you need to push very hard as otherwise the distributor cap doesn`t fit like with the others.

Perhaps in your situation it is the other way round and the rotor is pushed down easily, but creates too much distance between the rotor tip and the contacts in the cap causing the current situation.

Rob

Reb Smith

Original Poster:

11 posts

197 months

Monday 2nd November 2009
quotequote all
Thanks. I did ask and hopefuuly got the rotor for the specific dizzy, but I will check again.