King ecu solenoid issues

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hitman2
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Re: King ecu solenoid issues

#21 Post by hitman2 » Tue May 04, 2021 11:27 am

Its totally bypassing the lpg ecu, I've took a 12v live when ignition is on and an earth, the solenoid on the lpg valve pulls the plunger in fine when not screwed into the reducer, it also pulls in fine on first insertion into the reducer, after that it fails to open. The coil has a steady 13.6v and it still won't pull the plunger to allow gas through.

Its got me beat, I've tried swapping internals from the rear valve and the rear one works okay with internals swapped but front same again one go and then nothing doing. 🙄

hitman2
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Re: King ecu solenoid issues

#22 Post by hitman2 » Fri May 14, 2021 12:25 pm

Tried some experiments this morning, appears that once the solenoid coil gets hot (too hot to handle for long) the magnetic affect is over ridden by the spring in the plunger, worked well about 20 times until the solenoid got hot, then fails to have enough magnetism to open the valve.
Internals removed from the valve for good now 🙄

LPGC
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Re: King ecu solenoid issues

#23 Post by LPGC » Fri May 14, 2021 4:31 pm

Reads like the solenoid coil is partially short circuited, decreasing it's resistance so it pulls more amps than it should and makes more heat.. Then maybe when it's hot it goes open circuit or resistance increases and lower amps through fewer coils has less magnetic pull... It shouldn't get too hot to touch - Change the coil ;-)
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hitman2
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Re: King ecu solenoid issues

#24 Post by hitman2 » Sat May 15, 2021 10:55 am

Hi Simon, this is the new coil 😂

Just pulled up some temps this morning after 10 mins running coil is up to 78 deg, valve opens and closes ok.
After another 10 mins coil is up to 90 degrees valve becomes inoperable, so if this is not the normal temperature of the coil maybe the one supplied is goosed?

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Re: King ecu solenoid issues

#25 Post by hitman2 » Tue Jul 20, 2021 4:49 pm

To put this thread to bed :-

Turns out I had only 2 issues, one the leak on the lpg vapour manifold hose, not evident all the time and worse when the system had warmed up, and two the multivalve, noticed that sometimes closing and opening up the isolation valve on the multivalve would allow the car to run on lpg for a while, this was after repairs to leaking manifold hose, then I discovered that the supply line from the multivalve was quite frosty one time, since removing the restriction device (velocity check valve) from the supply line car is running fine.Guess just wear and tear on the multivalve was causing the internals to stick or spring had weakened over time.

New filters installed, new temp sensors fitted, replaced coil and added relay to system, also dismantled reducer and replaced o rings to water elbows, replaced some hose.

Been a chasing my tail exercise but got there in the end, eventually 👍

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Re: King ecu solenoid issues

#26 Post by LPGC » Wed Jul 21, 2021 8:32 pm

Did you get the correct solenoid coil for the multivalve? On some mv's it is possible to fit a 3Ohm coil that is intended for certain types of injectors, a 3Ohm coil would get very hot very soon with a constant 12V feed.

Frosting on the line from tank to reducer doesn't seem good, what type of mv is fitted? It's unusual for the liquid pickup pipe on a multivalve to come off (so the pickup pipe might get vapour instead of liquid and that could cause frosting) but some types of mv are more prone to that than others. The only other things that could cause that gas line to frost would be if it were too narrow for the engine's demand at high loads, or if the mv can't supply enough gas for the engine's demands at high loads, or if there's a severe leak.
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
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2 miles A1, 8 miles M62,
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hitman2
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Joined: Tue Mar 30, 2021 4:17 pm

Re: King ecu solenoid issues

#27 Post by hitman2 » Thu Jul 22, 2021 10:10 am

LPGC wrote:
Wed Jul 21, 2021 8:32 pm
Did you get the correct solenoid coil for the multivalve? On some mv's it is possible to fit a 3Ohm coil that is intended for certain types of injectors, a 3Ohm coil would get very hot very soon with a constant 12V feed.

Didn't change coil on multivalve

Frosting on the line from tank to reducer doesn't seem good, what type of mv is fitted? It's unusual for the liquid pickup pipe on a multivalve to come off (so the pickup pipe might get vapour instead of liquid and that could cause frosting) but some types of mv are more prone to that than others. The only other things that could cause that gas line to frost would be if it were too narrow for the engine's demand at high loads, or if the mv can't supply enough gas for the engine's demands at high loads, or if there's a severe leak.

Leak sorted, wasn't severe but severe enough to drop pressure when hot below threshold to stay on gas, rotarex multivalve, dip tube was secured fine, either a bit of dirt or weakness or age in flow restrictor was cause, all sorted and running fine now.No frost without flow restrictor.
Trigger wires from lpg ecu driving relay for front solenoid on old coil, original coil still on tank valve.

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