Which engine? Which engine management? Which LPG management?
Normally, not enough gas pressure or not enough water temperature in the vapouriser.
Peter
Normally, not enough gas pressure or not enough water temperature in the vapouriser.
Peter
LAMPRO
Active Member
hi pete it's a zavoli lpg system, on a thor v8 d2 I recon on pressure as I have bled the coolent so no air locks and the pipes to the vap are hot, I routed them the same way they went in before through the heater matrix at the bulk head but there again I have cool air not hot coming from the heater aswell
Pity you're so far away, I have the lead and software to look at the Zavoli ECU.
If the vapouriser is hot then it's likely pressure or lack of, are the valves clicking on and off in the LPG pre-test? One on the tank should do it before the change-over.
Peter
If the vapouriser is hot then it's likely pressure or lack of, are the valves clicking on and off in the LPG pre-test? One on the tank should do it before the change-over.
Peter
On start-up, ours will run through a sequence that is initiated when the vapouriser gets warm enough, then the valves are tested (like a machine gun on ours) then it will turn on the gas and wait until the revs are at the change-over point before switching fully to gas by switching the petrol injector drives to the gas solenoid valves.
Interesting that when you watch the screen, the gas valves run according to the petrol settings but with an increase in valve open time to make up for the loss of power on LPG.
We did our son's D2 V8 back in June, got the updated software then, although the older version wasn't that bad.
Peter
Interesting that when you watch the screen, the gas valves run according to the petrol settings but with an increase in valve open time to make up for the loss of power on LPG.
We did our son's D2 V8 back in June, got the updated software then, although the older version wasn't that bad.
Peter
not quite true...the gas injectors run at a lower pressure than petrol,(so less fuel injected, so more time required, though this compensated by larger injectors to a degree) also more importantly the gas injectors HAVE to run longer injector times..they cant run shorter cos as they are directly following petrol injector times they wouldnt know where to stop if cut off before..
if you get my drift??
but lpg can be just as powerful, as one can advance the timing so much to utilise the 108 ron thus making up for the lack of calorific value compared to normal petrol..
however..it not changing over...lpg system requires
1st an rpm signal..to tell if present press the change over switch with engine running, if the lpg leds start to flash then it has the rpm..if the petrol led is the only one on then no rpm signal.(as in when ign on, but not running)
2nd needs vaporiser to be at a set temp (user adjustable)
3rd..gas in tank!!
thats it..once up to temp, it will switch on the tank and vaporisor solenoid to pressure up the system..the pressure sensor will detect gas pressure (if present) and once user setable rpm is reached (acellerating or decelerating (user setable..SET decelel) and after a preset (user setable) time delay will switch on the lpg injectors and cut off petrol injectors..
IF no gas will not switch over..SO CHECK the multivalve taps are open!!(2 screw valves on multivalue)
if internal tank..ie in the boot they is under the plastic clear round cover..(if multivalve single hole)..if external no cover
if 4 hole tank then they are not actually a multivalve but will be under the long oblong cover..most then dont have shut of valves..no idea why..
if 4 hole tank then they are not actually a multivalve but will be under the long oblong cover..most then dont have shut of valves..no idea why..
LAMPRO
Active Member
Well managed to sort it with a fluke, noticed exspansion tank was still not at full level so I ran the engine and topped up, all of a sudden a massive gurgle noise came out from around the heater matrix and then the lpg turn over, must have been a big air loock preventing the flow of coolent around the matrix and vap so not getting up too required temp to change over, took her out for a run last night and touch wood it all sorted thanks for all the help
That's another good reason to go for the series water connection 
Peter
Peter
It does depend on the vapouriser water passages, or rather the connections. On ours I opened them up as there was plenty of metal inside the connection.
Given the small number of extremely cold starts we get here, I'd trade the quicker change to gas for the heater warm up time.
Yesterday I went up to the farm to drain the trailer water heater, it was a fairly heavy frost but the heater was toasty within 3 miles or so, starts to de-ice the windscreen before the gas change-over if I leave it running and scrape the side windows, so not that bad.
Peter
Given the small number of extremely cold starts we get here, I'd trade the quicker change to gas for the heater warm up time.
Yesterday I went up to the farm to drain the trailer water heater, it was a fairly heavy frost but the heater was toasty within 3 miles or so, starts to de-ice the windscreen before the gas change-over if I leave it running and scrape the side windows, so not that bad.
Peter
