New distributor cap

[paulbell6]

Hi all, just bought and fitted a new cap, leads and rotor arm in an attempt to rectify a poor running situation, and in doing so I was amazed that it worsened the running almost to the point of what seemed like half the cylinders were not firing, so I switched off. Before I removed the new items I noticed that I could move the cap around quite freely, with the clips attached I could rotate it backwards and forwards by about 5mm, and I could lift it by a couple of mm. I put the old ones back on and the car returned to almost running sweetly. Yes, the leads were correct.
i just wondered if anyone had come across this problem before. More second rate reproduction items maybe?

Paul

[martin]

Hi Paul, cheaply made cap, what colour is it ? M.

[V Mad]

You may have stumbled across the cause of bad running. If the rotor arm were correctly centred then a small rotation of the cap would not have any effect. If it was off angle then it might.

So I would look into the fit of the rotor arm. Maybe another dodgy pattern part?

Anyway 5mm is way too much. Sned it back.

[alistair260661]

not had problems re the cap, but I did have a major issue with a new set of OE leads (from a major supplier - who subsequently took them back) - the resistance was significantly different from the old ones and it didn't run worth a b*****. I presume your new cap is an OE, not one of those blue or cheapo black ones - they can have significant fit issues as you mention - and have you checked that the centre contact (inside) is actually "springy" and in good contact with the rotor arm..............?

[paulbell6]

Hi guys, thanks for the replies, Martin the cap is black and has no discernible markings on it so maybe it's just a pattern part. Alistair, I have not checked the spring connector in the centre but the look and feel of the cap and it's cost make me think it's a duffer. It was about £12. When you talk about the difference in resistance in the leads what were the figures that you were getting. With that info I can check them all out.

Thanks guys

Paul

[Stagsongas]

Paul,

When I bought my car it had all sorts of misfiring issues. I did all the usual but the new set of blue HT leads Mr PO had just fitted proved to be the culprit (not naming the source).

I do a huge amount of HT fault finding in my business so I know how to cure it. A brand new set of Bearmach leads for Range Rover 3.9 (£16.50) where fitted and all my problems went away (until the next, seperate problem arose )

Although these would be called 'budget' leads they really are very good, the insulation is thicker than most and made of soft silicon. This is provable as we put them under more load than when on petrol. As a bonus, they are black. I really don't like gaudy colour ign. components because it has formed an association with poor quality in my mind. It's a good maxim to work by - never seen a good quality blue cap for many years. As you suggest, even the 'feel' of the plastic gives clues, hard and brittle usually means cheap and useless.

Good Luck

Steve

[paulbell6]

Hi Steve, where do you get the leads from?

Thanks

Paul

[iani]

Hi Steve, where do you get the leads from?

Thanks

Paul

Rimmers sell Bearmach parts for Landrovers

[paulbell6]

Thanks

Paul

[Stagsongas]

Hi Steve, where do you get the leads from?

Thanks

Paul

I use a company called MM 4 x 4 which is conveniently 2 miles from home. If you want that price ( I may have got some trade discount) then they're the people to contact. They do card sales and all that.

Regards

Steve

[paulbell6]

Morning all, yesterday I swapped all the old plug leads with the new ones, keeping the original distributor cap in place and the engine ran as normal, that is with the annoying slightly rough running. At least I have proven that the new leads are good and that the new cap is useless. I will be sending it back to the supplier. So I may still have a problem with the old cap but where can I buy a decent one from?
in the meantime I have booked the car into a local carb specialist for him to give them the once over. Interestingly he is a Stag owner so I feel I will be in safe hands. Fingers crossed!

Paul