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Discussion Starter · #1 ·
Hi all.

My RR has always chomped through caps pretty quickly. I've used a variety of types and had lots of people recommend Power Spark caps. I've not found these any better than cheaper ones/Lucas. Does anyone have an opinion? Is there any difference between the black and blue ones other than colour? Does anyone think that genuine parts are significantly better?

Thanks
 

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I get my cap and rotor at autozone……
Work fine…
If I get a year… I’m good…
But they last longer than that…
 

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You should be able to get more than a year our of a cap. I take my cap off every oil change and wipe it out. They are prone to carbon tracing that could cause irregular running. Been running a black cap for two years now without issue.
 

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I have the blue one on my '95 3.9, been on there for over 50,000 miles / 10 yrs, no maintenance other than an annual scrape of any deposits on the electrodes and a wipe out to clean the dust from it.
I think you should be asking a different question; what's wrong with my dissy that's making it eat caps? :)
 

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You win..,!
 

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Discussion Starter · #6 ·
Yes... I've asked that question before and not had much joy. I'm not an expert on distributors so don't really know what would cause it. It does little mileage but can easily go through two a year. I scrape the deposits, but a short ride out sees them return quite quickly. Once started, it's generally fine and runs well with an older cap, but in colder weather the cap causes me issues with cold starting if it's not tip-top. There are no other running issues.

Advice gratefully received
 

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1970-1995 Range Rover Classic
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Not that I have a lot of data to go on, but when I had running issues with lack of spark (luckily I had save the old cap and rotor) it turned out to be the rotor that was driving the problem. I had recently replaced the cap and rotor and everything seemed to be ok for a short while, but one afternoon it started loosing power and barely coasted into a gas station parking lot. Eventually had to drag it home. after much troubleshooting I determined it to be the cap/rotor. My determination was that the gap between the rotor and the electrode in the cap was excessive. the electrode spacing appeared to be the same as the previously removed cap, but the rotor was significantly shorter. I calculated the gap based on the contact wear mark on top of the rotor and length to the tip, and the distance from the center of the cap to the electrode. this gap ended up being significantly larger that the actual spark plug gap. I then removed the screw in that holds the copper track on the rotor and elongated the hole so I could move the track closer to the electrode in the cap. I don;t know exactly where I ended gap wise, but was shooting for spark plug gap or just under. after reassembly it started right up and has been running that way for years.

Coincidentally I have a friend with a 350 powered boat that was having all sorts of running issues, that ened up having the exact same problem.

Seems the QC on new distributor/rotors isn't what it used to be.
 

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1970-1995 Range Rover Classic
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been years since I've had the cap off my RRC. I may be mistaken on that one. i may have just put the original I had pulled off back on, but again I'd have to go look at it. I know for sure that I extended the rotor on his boat motor.

 

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1985 RRC 3.5, LT230, LT77. 1996 Disco1, 4.0
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I switched over to the "red" rotor, don't log many miles anymore, however, haven't had the cap off for a year. For me, alot of the small misfires were resolved with said rotor arm. It's worth a try, as they are less expensive than a new dizzy system. Any small crack or poor alignment of/in the cap will cause issues too. I use a small amount of plumbers grease on cap base to dizzy surface. If yours was equipped with the internal plastic cover and it's missing, you'll have issues too. I'm running a black cap.
 

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Hah, I just googled Rover V8 rotor arm and couldn't believe the different designs that came up. I'm not sure I would trust anything that had joints, rivets etc in it. Mine is one long piece of brass(?) embedded into the plastic, never gives any trouble (he said with fingers crossed!).
Tool Font Auto part Fashion accessory Metal
 
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