Rumble in the force
Moderator: phpBB2 - Administrators
sorry ? don't get this and it is hardly helpful . . . the distributor has 2mm play up and down and play side to side as the poster said. . this is a heavily worn distributor, it will have a lot of spark scatter as the shaft rattles around in the bearing, and as it moves up and down the centre contact in the cap will not be consistent what has this to do with "worn electronics" it is a worn distributor and will not even give a reliable trigger with an electronic pick up as the air gap varies.DaveEFI wrote:Just out of interest, what do you reckon wears out in the electronics of a dizzy to cause these symptoms? A worn dizzy can well cause incorrect timing - but this is relatively easily checked.kiwicar wrote:Hi
From that description I would say it was normal play for a 280km old distributor, ie it is thoroughly worn out. In light of the fact you run this on LPG and that really shows up any weekness in the ignition then I think the "shotgun" aproach is entirly apropriate in this case, change the lot for good quality new kit. If the cam has done more than 100,000km I would change that and the tappets at the same time, the drive gear on the cam will also be shot and the cam lobes will be worn.
Best regards
Mike
best regards
Mike
poppet valves rule!
There is up and down movement of the rotor arm section relative to the main shaft on every dizzy I've ever seen.
The air gap to a VR sensor is not super critical - in the same way as a points gap is. The electronics look for the zero crossing point in the sine wave output - not amplitude.
The air gap to a VR sensor is not super critical - in the same way as a points gap is. The electronics look for the zero crossing point in the sine wave output - not amplitude.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Hi
yes but the up/down movement translates to a variable lead/lag thanks to that lovely gear on the cam/bottom of the distributor, so a change in timing of said crossing points on the VR sensor, chuck in a progressive/regressive rotation in a worn bearing of the distributor shaft adding even more scatter and you get a mess of sparks. Sorry Dave but I cannot see why you would not change such an old distributor, add in 10+ year old semi conductors solder joints and old lucas wiring and old spark leads and I would just change the lot (coil as well). Spark scatter and weak sparks are not good for reliable LPG running, when I had the stuff on my RR I was forever changing the components of the ignition system, it was one of the reasons I hated the stuff it costs a fortune in ignition components but life with LPG and old ignition is just not worth it.
Best regards
Mike
yes but the up/down movement translates to a variable lead/lag thanks to that lovely gear on the cam/bottom of the distributor, so a change in timing of said crossing points on the VR sensor, chuck in a progressive/regressive rotation in a worn bearing of the distributor shaft adding even more scatter and you get a mess of sparks. Sorry Dave but I cannot see why you would not change such an old distributor, add in 10+ year old semi conductors solder joints and old lucas wiring and old spark leads and I would just change the lot (coil as well). Spark scatter and weak sparks are not good for reliable LPG running, when I had the stuff on my RR I was forever changing the components of the ignition system, it was one of the reasons I hated the stuff it costs a fortune in ignition components but life with LPG and old ignition is just not worth it.
Best regards
Mike
poppet valves rule!
My concern is the quality/life of these reproduction Lucas dizzies. From what I've heard, it's poor.
IMHO is always better to try and find out what the fault actually is, rather than just throw new parts and money at it. It's my Aberdonian upbringing.
IMHO is always better to try and find out what the fault actually is, rather than just throw new parts and money at it. It's my Aberdonian upbringing.
Dave
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
London SW
Rover SD1 VDP EFI
MegaSquirt2 V3
EDIS8
Tech Edge 2Y
Hi Dave
I would normally agree with you on this, however I spent a long time trying to get the ignition right on my LPG conversion chasing faults changing one component at a time, the trouble was, for LPG to work properly you recon on a coil life of about 20K miles, plug leads of about 9K plugs 6K distributor cap about 10 k distributor (a good one) about 45K, stupid little retard box so you can start it on petrol about 20K. If you actually use the thing between changing components you find by you have changed three items the first one you changed has worn out. It is far better to change the lot for new in one go so you start with known good ignition (and don't waste money on anything other than top quality components) then change them again at those intervals, there is no point in struggling with anything but new first class condition ignition components unless you can afford to change MAFs every time the thing backfires because of spark scatter.
Best regards
Mike
I would normally agree with you on this, however I spent a long time trying to get the ignition right on my LPG conversion chasing faults changing one component at a time, the trouble was, for LPG to work properly you recon on a coil life of about 20K miles, plug leads of about 9K plugs 6K distributor cap about 10 k distributor (a good one) about 45K, stupid little retard box so you can start it on petrol about 20K. If you actually use the thing between changing components you find by you have changed three items the first one you changed has worn out. It is far better to change the lot for new in one go so you start with known good ignition (and don't waste money on anything other than top quality components) then change them again at those intervals, there is no point in struggling with anything but new first class condition ignition components unless you can afford to change MAFs every time the thing backfires because of spark scatter.
Best regards
Mike
poppet valves rule!
Hi Dave
You are spot on. . you need a lot of advance for LPG ,like 42 to 45 degrees or so, that alone on makes it liable to cross firing. . . Add to that any scatter and you are in backfire city, not helped by the fact you are generally running an injection manifold that was designed to run dry plenum in a wet plenum mode and then on top of all that you need to run it at it's best output or the stuff will not ignite properly you really need crank triggering as a minimum. What this boils down to is that an ignition system that is fine on petrol can be useless on LPG. I found I had to treat the ignition components as consumables like air and oil filters, changing the ignition system components on the timescales above this in turn sure ate into any claimed savings in running costs of the stuff. . . never again! I still think you are far better off just fitting a megasquirt and not bothering to go gas at all if you want to reduce running costs.
Best regards
Mike
You are spot on. . you need a lot of advance for LPG ,like 42 to 45 degrees or so, that alone on makes it liable to cross firing. . . Add to that any scatter and you are in backfire city, not helped by the fact you are generally running an injection manifold that was designed to run dry plenum in a wet plenum mode and then on top of all that you need to run it at it's best output or the stuff will not ignite properly you really need crank triggering as a minimum. What this boils down to is that an ignition system that is fine on petrol can be useless on LPG. I found I had to treat the ignition components as consumables like air and oil filters, changing the ignition system components on the timescales above this in turn sure ate into any claimed savings in running costs of the stuff. . . never again! I still think you are far better off just fitting a megasquirt and not bothering to go gas at all if you want to reduce running costs.
Best regards
Mike
poppet valves rule!
V8 tuner recommends this :
http://www.v8tuner.co.uk/product.php?id=516
They say that shaft play up and down is normal.
Also they say tho check everything before buying
A lot of friendly advice like always.
I am running on lpg almost a decade, never had a lot op problems with it untill now.
Strange thing is that now the engine runs almost perfectly, wath i see is that when i put the advance @ 8 degree the dizzy almost hits the waterpomp with the vacuum advance
Everything in the engine is new (timing gears,camshaft,lifters,etc..)
Also there is a little of tjierping noise @ the lhd side of the engine, if the rocker cover is removed it is very difficult to hear, did found a couple of rubber washers in there, looks like pices of the valve seals ( i fitted the 3.5 origenel stuff because i did not know i could replace them with the good 3.9 seals
)
http://www.v8tuner.co.uk/product.php?id=516
They say that shaft play up and down is normal.
Also they say tho check everything before buying
A lot of friendly advice like always.
I am running on lpg almost a decade, never had a lot op problems with it untill now.
Strange thing is that now the engine runs almost perfectly, wath i see is that when i put the advance @ 8 degree the dizzy almost hits the waterpomp with the vacuum advance
Everything in the engine is new (timing gears,camshaft,lifters,etc..)
Also there is a little of tjierping noise @ the lhd side of the engine, if the rocker cover is removed it is very difficult to hear, did found a couple of rubber washers in there, looks like pices of the valve seals ( i fitted the 3.5 origenel stuff because i did not know i could replace them with the good 3.9 seals
)Writing English is a bitt of a problem....
Somedays it works good, this day i t shakes like a diesel on idle
I checked the spark and it is not verry blue, more blue with a yellow tip.
The spark also dances at the spark plug.
If i blow at the tip off the plug i can also blow the spark away so i think the ignition is weak and not always correct on timing.
I tried to fit a rmp gauge if i use the W clamp the engine runs @ 2500 rpm idle and i get 10 000 rpm with a bit of throttle
When i use the - clamp on the coil where the amplifier is also fitted to i get 500 rpm idle and with throttle it slowy go's up and ever slower down
According to my fluke my W clamp gives AC on idle ???? and DC 8 Volt @ throttle
I checked the spark and it is not verry blue, more blue with a yellow tip.
The spark also dances at the spark plug.
If i blow at the tip off the plug i can also blow the spark away so i think the ignition is weak and not always correct on timing.
I tried to fit a rmp gauge if i use the W clamp the engine runs @ 2500 rpm idle and i get 10 000 rpm with a bit of throttle
When i use the - clamp on the coil where the amplifier is also fitted to i get 500 rpm idle and with throttle it slowy go's up and ever slower down
According to my fluke my W clamp gives AC on idle ???? and DC 8 Volt @ throttle
Writing English is a bitt of a problem....
