confusled

Heres one for ya guys. 3.5 v8 8.25:1 on twin refurbished SU hif 6 carbs and mk17 lumenition ignition. I got the carbs and choke all sorted a few weeks back as it went very lean when out due to poor so called professional mechanics in the past.

Took it out laning and long country drive this weekend, about 40 odd miles stopped for a picnic, and at a pub and for icecream. I noticed just before the last stop under full throttle she seemed a little "missy" but I though maybe it was still a tad lean.

Made the stop and only with half a mile to home drove off and pulled up on drive, while I was waiting for the garage door to open it was at idle then as I bliped the throttle to bring it inside quite a flat spot when as I went through the first garage on my way to the 2nd one it cut out and it really would not start!

after ages of cranking and then leaving it for 20 mins and then more cranking I decided to drive it up the slope in tot he garage on the starter in low range and half way up it started but it still had a bad flat spot just off idle and a slight miss if revved but it idles well.

so yesterday I thought it must still be lean or gone off song, pulled the plugs and they were perfect and ran it up and all the carbs are still perfect and it now runs great so what the fook is it??????

I wonder if the lumention module is playing up as its a used one, the magic eye was new about 300 miles ago.

Fuel evaporation or fuel pump?

Peter

pumps good, you can hear it tapping away and its new too but I did wonder about it getting the vapours in the float bowls , I dont think it would be in the line as the pumps at the back axel and the system runs a continuous loop back to the tank which keeps it cool

crack in the rotor arm - when it gets hot it opens up and won't work?

"I wonder if the lumention module is playing up as its a used one"

I doubt it i've been runing a car with one fitted for the last 36 years without a hint of a problem, if fact untouched from the day i fitted it, but there's aways a first as they say.

At least it does away with the points and "rotor arm"

I would check that the damper pistons are rising and not sticking, maybe when hot.
Do you have lean needles? and are the needles set at the correct height?

My old 3.5 didn't like a lean mixture, they run hot, might be good for the environment but not much fun

I also would initially think something electrical.

Stopping and than perfectly working is not often mechanical.

Not sure what elecs you got for your engine, but I had a relay playing up in the past. It reacted to different temperatures and moisture in the air.

I will look at the rotor although its v low miles. how would I check the dampers? they seem to work fine, the needles are for a triumph tr8 I think but andrew turner said they would be fine on a range rover and he set them up, not sure if thats good or bad as I already had one float sticking tbh lol.

I have a new lumention module in the boot so I may start with that as a no cost option. when I ran it up in the garage yesterday I have to say that within 20 or 30 mins the module was too hot to touch with nitrile gloves on so I am not sure that is correct?

They do get warm after all the case is a heat sink.
But if your running with a FK117, getting hot maybe understandable, it's designed for a 4 or 6 cylinder ignition system.
For a V8 FK114 is the module to use.

interesting, I have only ever seen the one universal module, for example rimmers only sell one module and magic eye and you just buy a fitting kit to suite your dizzy.

I gathered the one module type and eye type were both the latest mk17 variants according the lumention website and no others were current, am I wrong?

Just looked at their site, as I did wonder. I expect the company would confirm what u have existing is ok or not.. I could be out of date info that is.

http://www.lumenition.com/new/support/lumign/fitting/Optronic_Applications.pdf

Interestingly for me I have a 001 kit fitted to one of my other cars, back in 1978 @ £28.11.

I have to say I find that table etc confusing lol.

correct me if I am wrong but that fitting kit is just the parts to fit the magic eye in to the dizzy not the module and eye?

I thought the black module was for race engines looking at there website?

Ok, PMAZ is the MK17 Power Module (ECU) and FK117 the the dizzy fitting kit for a V8 dizzy according to their price list.
http://www.lumenition.com/new/prices/2010_RETAIL.pdf


So if you have those items fitted all should be ok.

yeah but I have the pma50 set up with fk114 like this:

Lumenition Optronic Standard Ignition PMA50/FK114 System for 35D8 at www.rimmerbros.co.uk

if you look its listed for range rover v8.

so do you have the black performance module fitted instead of the plain alloy one?

If that is your dizzy( Lucas 35D8) then that's the kit u should have, I doubt that is the reason for your problem.
And standard ECU is alloy.

yeah between our chats I called them and the std one is fine for rv8.

anyhoo I swapped the module as I had a new one on the shelf and its running ok- but it was before lol. needing a 30 mile plus test run is not so easy.

I also swapped out the rotor arm which after just 300 miles looked too burnt for my liking although the cap was fine.

final job was to swap my totally failed ammeter for a wobbly but working one.

I have to say that after doing all those jobs I noticed my rev counter was a little jumpier than usual at idle, it takes it signal from the coil negative (lumenition 6v coil with ballast)

Any ideas if any of todays jobs (or what) would cause that? I am not really in to lectrics

Speak to lumenition about your rev counter issue they are or were very helpfull.

All I know is the ballast has to be removed on some vehicles but I believe that due to starting problems.

yeah its there coil and ballast , its the correct set up. what confused me is the revcounter wasnt doing it before I changed the module and rotor and ammeter so which caused it? lol

coil breaking down...fuel vaporising in lines...ballast resistor/wire breaking down...dodgy power feed..etc.
never had a problem as you describe that turned out to be carb/s..if carbs i found problem usually constent.

you must be bored today lol yeah I dont think its the carbs either now they are sorted.

cant be the vapours as the pumps at the back and running a continuous loop and the coil and wiring are new but I do wonder about the coil even though its a new lumention one. Hard to test it when it needs a 40 mile run to get the problem to occur. runs fine atm, I will try it when next out in that one.