zoltan Posted June 9, 2011 Share Posted June 9, 2011 Ive fitted MS1 V3 onto my Gaz Russian truck, a lazy 4.2 low compression ZMZ V8 and although it is a little lazy to start from cold the main issue I'm faced with preventing further progress is that having run and started to warm up it flatly refuses to spark once it has been stopped. Ive only got as far as tuning the idle and a quick roll round a paddock in first as I dare not take it out on the road like this Ive attached a datalog of its failure to show spark: once it stops cranking the ignition shows advance but this dissappears to -0.1 on cranking. Very occasionally I get a single plug firing. Some of this could be battery voltage, what is the lowest that MS will operate at under cranking and does EDIS switch off down at low volts too? Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 9, 2011 Author Share Posted June 9, 2011 It looks like I have not attached the datalog despite saving it as a .txt file "Error You aren't permitted to upload this kind of file" Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 9, 2011 Author Share Posted June 9, 2011 have read this http://forums.lr4x4.com/index.php?showtopic=68638 so try with .xls and same, nothing "Error You aren't permitted to upload this kind of file" Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 9, 2011 Share Posted June 9, 2011 May be low voltage but could also be a duff VR sensor, EDIS should fire sparks whether the ECU's working or not. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted June 11, 2011 Share Posted June 11, 2011 Ditto - mine even went through an MOT without comms between MS and EDIS. I suggest you look around the EDIS unit for problems. What does the voltage drop to upon cranking? Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 11, 2011 Author Share Posted June 11, 2011 Ive changed the VR sensor, tried reversing the polarity, tried different coils and just about run through everything short of puling the loom apart. Voltage is dropping to 6 1/2 to 7 volts I'm going to doublecheck where my static timing is as it is backfiring too much when it does agree to run. Shame is my V8 in the LandRover runs faultlessly and the whole point of this exercise was to ditch the cranky Russian carb and points dizzy Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted June 11, 2011 Share Posted June 11, 2011 Fails to spark or just fails to start ? Nige Quote Link to comment Share on other sites More sharing options...
steve_d Posted June 11, 2011 Share Posted June 11, 2011 Despite thinking I was pretty good at electrics I still managed to connect the low tension wires to the wrong coils. Somehow it did partially run which may be the position you are in. Also 6.5-7 volts is pretty low so a booster battery could be a good idea to eliminate that. Steve Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted June 12, 2011 Share Posted June 12, 2011 I'd say that 6.5-7 volts is more or less the lower limit for MS operation. Certainly much lower and it'll fall over. I'd imagine the lower limits for EDIS are similar. I think a booster battery might be a good bet... Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 13, 2011 Author Share Posted June 13, 2011 After much wrestling with the pig at the weekend, there is spark and the starting problems probably lie with the fuel delivery. I got the pig running on its old carb so the sparks are present. That leaves the fuel. I'm running a low pressure pump from the tank to a swirl pot then a high pressure pump around the fuel rail. I suspect I might have failed to put a restrictor in the swirl pot to tank return line so the swirl pot is not staying full. That said I should hear that in the fuel pump. It started raining and I got more interested in the LPG wiring For the time being I will run the fuel pump direct to and from the tank and get everything running fine before tinkering with the swirl pot. I'm also only a switch and a 12v feed from having the LPG working so at least the pig can move Quote Link to comment Share on other sites More sharing options...
steve_d Posted June 14, 2011 Share Posted June 14, 2011 ....That leaves the fuel. I'm running a low pressure pump from the tank to a swirl pot then a high pressure pump around the fuel rail. I suspect I might have failed to put a restrictor in the swirl pot to tank return line so the swirl pot is not staying full. That said I should hear that in the fuel pump..... Provided the fuel coming into the pot is somewhere down the side of the pot and the return is coming out of the top then the only reason the fuel will return to the tank is because the LP pump is pushing it out of a now full swirl. The return pipe must also be at the top so air gets returned to the tank. If you believe the swirl pot is not full then it can only be because the LP pump is not keeping up with the fuel being used. If the swirl is not full and the engine hardly running then you have a dead LP pump or blocked filter. Steve Quote Link to comment Share on other sites More sharing options...
zim Posted June 14, 2011 Share Posted June 14, 2011 You have got the return from the engine going back into the swirl pot haven't you ? My swirl pot works perfectly, i can drain my main tank to totally empty and still have a full swirl pot. I have no restriction from the swirl pot back to the tank. Gordon Quote Link to comment Share on other sites More sharing options...
zoltan Posted June 14, 2011 Author Share Posted June 14, 2011 Provided the fuel coming into the pot is somewhere down the side of the pot and the return is coming out of the top then the only reason the fuel will return to the tank is because the LP pump is pushing it out of a now full swirl. The return pipe must also be at the top so air gets returned to the tank. If you believe the swirl pot is not full then it can only be because the LP pump is not keeping up with the fuel being used. If the swirl is not full and the engine hardly running then you have a dead LP pump or blocked filter. Steve The LP pump (SU points type, same as E type) feeds in to the top side of the pot. HP pump takes fuel from base of pot. Fuel rail return goes in top side of pot and tank return is from top of pot. I originally had a red top facet LP pump but changed away from this to the SU for fear that the Facet would not live long enough grinding away for hours on end. The SU is in a different league as far as build quality is concerned and is fixable at the side of the road if necessary. What are others using for the LP side? Quote Link to comment Share on other sites More sharing options...
zim Posted June 14, 2011 Share Posted June 14, 2011 I just use a normal facet solid state pump. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted June 15, 2011 Share Posted June 15, 2011 Facet red-top here, at least 20k miles on it now... Quote Link to comment Share on other sites More sharing options...
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