Graham Sewell Posted January 31, 2011 Share Posted January 31, 2011 As some of you may remember, I "upgraded" to MegaJolt last September to cure an intermittent misfire. Having left the car in the garage since October because of weather or work commitments, finally got to go for a blat yesterday. However, where the old clockwork system could fire up providing the starter cranked the engine over, MegaJolt seems to need much more oomph in the battery - which is a shame as it resembled a cold pancake on Ash Wednesday when I tried to coax the car into life. Fortunately, 4 hours on a charger rescued the situation - but limited the range of the blat due to light/time constraints. I guess the next upgrade will be a battery conditioner.... Cheers, Graham ------ Low tech luddite - xflow and proud! Edited by - Graham Sewell on 7 Mar 2011 13:59:06 Link to comment Share on other sites More sharing options...
Sheds Moderator Posted January 31, 2011 Share Posted January 31, 2011 That's a bugger Graham, I'm not familiar with the MegaJolt details but it couldn't be related to the ballast resistor could it? Just a guess, thinbking about the fact that batt voltge sinks under load. Link to comment Share on other sites More sharing options...
OliverSedlacek Posted January 31, 2011 Share Posted January 31, 2011 The Megajolt is probably mapped to provide a lot more advance at zero throttle and minimum RPM. This is not ideal for starting as you ideally want the engine to fire after TDC when cranking. A spark way before TDC means that the engine will try and run backwards. Link to comment Share on other sites More sharing options...
jonboylaw Posted February 2, 2011 Share Posted February 2, 2011 As Oliver says, if you zero the advance at 0 - 200 RPM, it goes to the default on the EDIS which is around 6 degrees I think and that should be fine for cranking. Either the map is out or your trigger wheel/sensor is not set at the correct angle. Jonathan ========================= My Flickr Gallery 92 Supersprint, Ford LSD LA, RK AX Crossflow. Stealth model (Matt Black and Ali), rebuild completed. Link to comment Share on other sites More sharing options...
richardm57 Posted February 2, 2011 Share Posted February 2, 2011 Hi Graham, Try removing cable from the megajolt box. This should default timming advance to 10 degrees. If then starts better you have to much advance at cranking or idle revs. I do this when weather is very cold.It also runs with less noise if you have bad neighbours. Richard Link to comment Share on other sites More sharing options...
Tony Whitley Posted February 2, 2011 Share Posted February 2, 2011 Don't you want it to run with more noise if you have bad neighbours? Link to comment Share on other sites More sharing options...
Graham Sewell Posted February 3, 2011 Author Share Posted February 3, 2011 The map shows 10 deg for engine speeds below 500rpm. So my guess is that during cranking the voltage drops below a level that the ECU require. After all, when the battery was charged (4 hours later), it fired on te first turn of the key. Cheers, Graham ------ Low tech luddite - xflow and proud! Link to comment Share on other sites More sharing options...
Griff Posted February 6, 2011 Share Posted February 6, 2011 Never had a problem with mine but I have a newish battery (though only a gel battery so small capacity) and keep it on a conditioner when not used for long periods. That said, when I rebuilt the engine I really drained the battery as I used the starter to pump oil through the system - it nevertheless started first time when I connected everything up. Are you sure you're running at the claimed advance? You need a dial gauge or some other good method of checking TDC and then the relative alignment of the trigger wheel. I used a modified school protractor and found the TDC notch on the pulley was quite a bit out. If the trigger wheel isn't set right you may have too much advance (or retard) on starting and when running, so what the display says could be deceiving. You don't need to move the trigger wheel if you find it's out, just go to the Tools menu, Global Controller Options and you'll see a setting for Trigger Offset you can play with. Good luck..! Mike Link to comment Share on other sites More sharing options...
Graham Sewell Posted March 7, 2011 Author Share Posted March 7, 2011 It now appears that the battery can hold its charge for less than 12 hours (charged on Friday night and could not start on Saturday morning). I have a new Banner on its way but am wondering if an Optimate could restore the old battery or is it likely to be a doorstop now? Link to comment Share on other sites More sharing options...
Sheds Moderator Posted March 7, 2011 Share Posted March 7, 2011 Generally speaking if they are dead they are dead. I have heard tales of people connecting a second battery in parallel with jump leads then charging BOTH overnight with a decent charger. The extra oomph from the second battery can sometimes bring it round. Often the reason they go down is that the sediment in the bottom shorts out a cell so the cell discharges, or so I'm told. You aren't fxing this with an OPtimate. Link to comment Share on other sites More sharing options...
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