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Post by dave1800 on Feb 20, 2013 2:23:30 GMT
Chris I will make you an expert on ignition timing yet!  LPG typically needs more ignition timing advance than petrol from idle to perhaps 3,000 rpm but then at higher rpm it needs less than petrol. So you can see the problem. If you have a distributor set correctly for petrol it will run retarded at low /med rpm which will reduce low down torque and not get the best economy. At high rpm it will be over advanced which is definitely not good for engine life. Conversely if you set a distributor correctly for LPG it may well knock using petrol up to say 3000rpm which is undesirable after which it will be retarded so power will fall off and use more fuel and possibly run too hot. That is why if you are running dual fuel then something like the 123 tune distributor or Aldon Amethyst that allow you to switch between 2 curves is attractive. So, it's not as easy as adding petrol - sorry Regards David Alexander, you'll have the 59D dizzy on your car. There's no reason that you can't stick some petrol in for testing purposes.......... The missing ballast resistor has made it as far as Stanstead Airport, according to Fed-ex tracking. Another day or so and we'll be in business. Chris. |
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Post by dave1800 on Feb 20, 2013 8:07:06 GMT
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Post by threelitre on Feb 20, 2013 10:01:37 GMT
Chris, the car has not seen petrol for ages - so I'll possibly need some gaskets before testing this. But I know the distributor is fine (for petrol) as it is the original spec. But LPG needs an earlier spark at low rpm and possibly less total advance (to be determined). So right now I run the car 4 degrees advanced over the factory settings (16 degree with vacuum removed at idle!) - it runs excellent in town with lots of torque and starts very easy on LPG (even at -8 degrees!). But being the perfectionist I am, I want to have the perfect advance curve for both fuels (even if I ever only use one), the distributor will not be too far of this for petrol, but for LPG I would need a device such as the Aldon to correct the settings.
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Post by Penguin45 on Feb 20, 2013 11:41:57 GMT
David, I have a couple of "single" ballast resistors in the garage, which would be fine for one side of the circuit. However, this one is a double with a secondary low resistance coil through it, which I think is part of a smoothing circuit. I could have picked this up separately, but the loom has keyway plugs fitted to suit the proper block, thus rendering it idiot (me!) proof. It'll keep a nice factory look to it as well. Just popped in home after my first two calls and they're here. Alexander, David has mentioned THE DISTRIBUTOR DOCTOR a couple of times - why not tell him what you need and see what he suggests. I've just got off the phone buying some new advance springs from him - very helpful. Nice fella. Chris. |
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Post by dave1800 on Feb 21, 2013 1:21:57 GMT
I knew there would be a good reason. I can only surmise like you that the low resistance coil is part of some RFI / smoothing mechanism. Should be all back together soon. By the way what did Martin (Dist Dr) advise on the springs? Regards David David, I have a couple of "single" ballast resistors in the garage, which would be fine for one side of the circuit. However, this one is a double with a secondary low resistance coil through it, which I think is part of a smoothing circuit. I could have picked this up separately, but the loom has keyway plugs fitted to suit the proper block, thus rendering it idiot (me!) proof. It'll keep a nice factory look to it as well. Chris. |
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Post by Penguin45 on Feb 21, 2013 20:06:49 GMT
Didn't have a lot of time to talk to Martin, but basically he said fit new standard springs as a starting point.
Chris.
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Post by threelitre on Feb 22, 2013 9:49:44 GMT
The thing is, that I would need to establish my requirements first. And here a little computer that you can use to change the ignition timing on the run is so much easier than fitting a set of springs and weights and then getting back on the test and repeat and repeat and repeat... So these modern gadgets are not really pointless if you ask me. The Aldon unit could also be a convinient way to correct the curve on the 3litre to be less fussy with fuel. It really wants 97 or higher RON, with 1/2 of the LRP fuels in sale in the UK during past travels it would pink. The switch in the unit can nicely be used to switch between 95 and 97 RON settings :-)
Alexander
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Post by dave1800 on Feb 22, 2013 23:55:22 GMT
Alexander
I've sent you a PM
regards
David
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Post by threelitre on Feb 24, 2013 23:14:29 GMT
David,
I will give it a thought. As an alternative, I've been looking at two units:
A kit from Jaytech ("Programmable High Energy Ignition"), which does about the same, but is only available in Australia, making it somewhat expensive.
And a piggy back ECU ("ECU Master Digital ECU Tuner 3"), which - if I understood the available docs - could also be used as an ignition only unit on older cars.
I have also looked into MegaJolt, but the installation is far more involved and - not a problem for me with my Maestro - immediatly spotted when peaking under the bonnet. All in all this is also the most expensive variant I looked at.
Regards,
Alexander
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Post by dave1800 on Feb 25, 2013 1:29:50 GMT
Alexander The Jaycar kit is available at a lower price via their UK website HERE but you would have to pay duty and VAT. An alternative if you are handy with a soldering iron is to buy the PCBs from the UK via EPE magazine. Main PCBs and Knock PCB. The article was published in Sept-Nov 2009 a reprint of Silicon Chip magazine from 2007. Programmed PICs are available from Silicon Chip or if you have access to a PIC programmer the software is a free download from both Silicon Chip and EPE. I built a couple for some people here and have recently done a mod to enable fine tuning on the fly with a pot. If you need further info circuits etc send me a PM. Work fine, not quite as easy to set up as the Amethyst as no laptop connection you have to use a 2 line x 16 LCD display. You can use the unit from any of the distributor based points trigger, Lumenition type optical, hall magnetic, reluctor (locking the weight advance mechanism) etc or use it to modify the output from an ECU. It comes in 3 or 4 modules. The main program board, the hand controller with the LCD to program the unit - usually removed once programmed, the coil driver and an optional knock sensor which fits inside the main board box. It has two switchable advance curves and you can program different advance for a given vacuum at different RPM unlike the Amethyst, but I didn't find a need to do this. You will also need a MAP sensor. The Magajolt looks good and there is a very active support group - you can also find them S/H on Ebay occasionally but still expensive. The Amethyst looks like a good compromise between price and hassle (a guaranteed working unit) to me and I plan to recommend it to people here with classics that have problem getting them to run properly with the available fuel. Regards David David, I will give it a thought. As an alternative, I've been looking at two units: A kit from Jaytech ("Programmable High Energy Ignition"), which does about the same, but is only available in Australia, making it somewhat expensive. And a piggy back ECU ("ECU Master Digital ECU Tuner 3"), which - if I understood the available docs - could also be used as an ignition only unit on older cars. I have also looked into MegaJolt, but the installation is far more involved and - not a problem for me with my Maestro - immediatly spotted when peaking under the bonnet. All in all this is also the most expensive variant I looked at. Regards, Alexander |
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Post by dave1800 on Feb 28, 2013 0:02:46 GMT
Chris
Apologies if I've missed anything but I am wondering how your distributor project is coming along?
Regards
David
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Post by Penguin45 on Feb 28, 2013 0:11:34 GMT
Mmm............ Assembled it all, mounted it all - doesn't work. Iggy module appears to be non-functional. Not a sign of a spark. Another Sunday afternoon I'll not see again. Gone mad - brand new unit on its way. Next Sunday, maybe. I've blagged a timing light, Adrian is eager to get it all working (I'm quite eager to get it all working!).............
In the meantime, I've had to put the old stuff back so as MrsP can get to work, as the Matiz is being somewhat recalcitrant.
Chris.
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Post by dave1800 on Feb 28, 2013 9:02:17 GMT
So sorry to hear that Chris I can understand your frustration. Maybe you were tempting fate by calling this thread RELIABLE ignition?  As an aside I have just read the latest thread on the PICO automotive scope site about an ECU failure (in the USA) caused by the failure of 3 electrolytic capacitors - that were relatively easy to to replace - for a few pence. This was a not uncommon problem with PC motherboards a few years ago and you could tell the ones that had failed as they were swollen at the top. Might be worth keeping in mind? Regards David Mmm............ Assembled it all, mounted it all - doesn't work. Iggy module appears to be non-functional. Not a sign of a spark. Another Sunday afternoon I'll not see again. Gone mad - brand new unit on its way. Next Sunday, maybe. I've blagged a timing light, Adrian is eager to get it all working (I'm quite eager to get it all working!)............. In the meantime, I've had to put the old stuff back so as MrsP can get to work, as the Matiz is being somewhat recalcitrant. Chris. |
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Alexander, you'll have the 59D dizzy on your car. There's no reason that you can't stick some petrol in for testing purposes.......... 
