changed injector 1 and cleaned distributor, but car still throwing p0201 at me.
Any one advise as to why or where to look next?
thanks
No change
Re: No change
Can't see any reason not to suspect petrol injector, or more likely wiring/connector to it, same as on a non-LPG car throwing code P0201.
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Re: No change
any idea how i can test this, the plugs for the injectors are all joined together in a plastic bar, so to take 1 off, they all got to come off,
then i believe there should be 10 volts at the injector plug, but wen do i test for this and how? can i just turn the ignition on with the plenum off to get these readings?
thanks
then i believe there should be 10 volts at the injector plug, but wen do i test for this and how? can i just turn the ignition on with the plenum off to get these readings?
thanks
Re: No change
No idea how you get at it on this car, many cars have the plugs assembled into a bar. When I have to get in, it's usually a dentist toothpick job for me, pinging open the plastic latches to withdraw individual plugs. Ask on a vauxhall forum maybe.
No sure why you'd expect 10 volts ; one side of each injector is usually at +12V with ignition on but gas off, the other side gets pulsed low when engine running. So with a meter you'd see it floating at 12V too, when engine stopped. I suppose if you monitored that with a DC meter while running it would show an average somewhere below 12V, but its not a very good test.
If you truly have a gas distributor system, the P0201 code has nothing to do with poor gas running, if that is still present.
No sure why you'd expect 10 volts ; one side of each injector is usually at +12V with ignition on but gas off, the other side gets pulsed low when engine running. So with a meter you'd see it floating at 12V too, when engine stopped. I suppose if you monitored that with a DC meter while running it would show an average somewhere below 12V, but its not a very good test.
If you truly have a gas distributor system, the P0201 code has nothing to do with poor gas running, if that is still present.
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the problem with the gas side of things i believe are because the ecu hasnt switch the cylinder back on , but the lpg ecu says its fine and the ecu switches off the eml light but leaves it running on 3 cylinders.
the info was from here :-
http://www.permoveo.ltd.uk/tabid/122/OB ... fault.aspx
the info was from here :-
http://www.permoveo.ltd.uk/tabid/122/OB ... fault.aspx
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Aha, you think it has killed the ignition on that cylinder deliberately, I hadn't thought of that. Certainly some cars do just that.daveylitz wrote:the problem with the gas side of things i believe are because the ecu hasnt switch the cylinder back on
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neither had i till i was kindly enlightened by PJPJ, still, today is another day and i will endeavor to beat this! lol
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If you truly have a gas distributor system, the P0201 code has nothing to do with poor gas running, if that is still present.
To add to that, the petrol injectors are, to complicate matters for you, connected through the LPG system. So that when you are running on LPG the petrol is not still injected as well. The LPG ECU controls a relay that isolates them but still feeds the required signal through to the main ECU. (I believe but can't confirm right now.)
The first thing you need to do is swap the suspect petrol injector with another on the bank, reset the main ECU code log (Very important), and run the car again until the fault re-appears. If the fault moves with the suspect injector then it is almost definately faulty.
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i tested the injectors and all four are fine, feeds to the injector i guess is next n then check on coil pack n that
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I don't think P0201 is a code generated by the coil-pack or ignition system. It is a code generated by the injector and/ or circuit and/ or controller for.
Is the resistance reading the same on that injector as the other three?
Sometimes coils (I'm talking about the coil in the injector) only fail when they reach a certain temperature. The only way to be sure it isn't the injector is to swap. Is this what you did?
Is the resistance reading the same on that injector as the other three?
Sometimes coils (I'm talking about the coil in the injector) only fail when they reach a certain temperature. The only way to be sure it isn't the injector is to swap. Is this what you did?
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yes i swapped it and appears no different, i gonna double check it all today.
how do i check the resistance? is this just a case of taking the wiring bar off and testing when the ignition is on to see if i get 12v?
if not, can you advise please. i have a multimeter n tools, so have what i need.
thanks.
how do i check the resistance? is this just a case of taking the wiring bar off and testing when the ignition is on to see if i get 12v?
if not, can you advise please. i have a multimeter n tools, so have what i need.
thanks.
Re: No change
If you have swapped the injectors and the fault has remained as P0201 after an ECU fault code log reset then it isn't likely to be that injector. However, so you know how to check the resistance of something use your multimeter set to resistance (Ohms, Omega symbol) and connect the test leads across the positive and negative of the coil (Usually the two pins on the connector of the injector in this case (Not the lead with the power on feeding the injector)). The reading you get is the resistance. Swap the test lead position to ensure there are no electronic components effecting the reading.
Plenty of websites for this kind of thing.
http://www.kpsec.freeuk.com/multimtr.htm
If it's not the injector then that leaves the wiring and/ or controller.
PM also sent.
Plenty of websites for this kind of thing.
http://www.kpsec.freeuk.com/multimtr.htm
If it's not the injector then that leaves the wiring and/ or controller.
PM also sent.
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cheers for that.
will post back with my readings.
will post back with my readings.
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In fact thinking some more, if the EML goes off when it is switched over to LPG then that would tell me~
1. The PCM is OK as the signal from the LPG relay is turning off the EML.
2. If the injector is definitely good (And there wasn't an accidental mixup and you put the injectors back in in the same positions) Then it must be a wiring issue between the LPG relay and the injector because it will only be the +12V that will be switched off by the relay or it is the other polarity wire that goes straight to the injector from the PCM.
From A to C the connection is always there so could be this.
From pin 1 on the relay to D is only used when running on petrol so could be this.
The diagram above is only to help describe what is meant, it may not be how the system is actually connected.
There must also be a way the LPG system provides an artificial injector resistance as well. You may find there is a resistor pack built into the system somewhere or may be the ECU provides it but this is working OK as the EML goes off when switched to LPG.
1. The PCM is OK as the signal from the LPG relay is turning off the EML.
2. If the injector is definitely good (And there wasn't an accidental mixup and you put the injectors back in in the same positions) Then it must be a wiring issue between the LPG relay and the injector because it will only be the +12V that will be switched off by the relay or it is the other polarity wire that goes straight to the injector from the PCM.
- Petrol Injector Disable.JPG (11.98 KiB) Viewed 4974 times
From pin 1 on the relay to D is only used when running on petrol so could be this.
The diagram above is only to help describe what is meant, it may not be how the system is actually connected.
There must also be a way the LPG system provides an artificial injector resistance as well. You may find there is a resistor pack built into the system somewhere or may be the ECU provides it but this is working OK as the EML goes off when switched to LPG.
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right, tested all injectors and they all reading 14.4 ohms, so defo not the injectors then
is there a test i can do on the injector plug to see if power is being sent down it?
thanks
is there a test i can do on the injector plug to see if power is being sent down it?
thanks
Re: No change
Change your multimeter to VDC (DC volts or a line with dots under it)
Connect the test leads to the pins from the harness that would normally go to the injector connector. Run motor on petrol to test.
Check against others if possible. Although the engine might stall when a second injector is not working.
However, you may well find that no voltage is present because the ECU will have switched it off anyway.
You will probably need to find the other ends of the cable and test for continuity using your meter set to resistance.
Connect the test leads to the pins from the harness that would normally go to the injector connector. Run motor on petrol to test.
Check against others if possible. Although the engine might stall when a second injector is not working.
However, you may well find that no voltage is present because the ECU will have switched it off anyway.
You will probably need to find the other ends of the cable and test for continuity using your meter set to resistance.
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also did a test from injector plug to ecu plug and got a continuity reading there, same with other the contact to earth
this isnt looking good is it? lol
this isnt looking good is it? lol
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because of the style of plugs, they all have to come off together, its a rigid plastic bar so cant just take one plug off.
i could however get access to the wires from the top, so could get into the wires if you think this is necessary
i could however get access to the wires from the top, so could get into the wires if you think this is necessary
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If you have continuity all the way through and they are all reading apx. the same, it sounds to me like it is a poor connection somewhere or a short to voltage.
It may be possible to exclude the relay by careful tracing back of wires. It may be a case of unplugging the LPG wiring and plugging straight through for the injectors excluding the LPG loop. I don't know for sure.
Check the connectors and wire for green or white dust/ gunge. Usually at the connection between the wire and pin.
You could install a temporary wire between the injector and ECU but this would probably mean knackering your harness.
It is probably worthwhile trying to take a reading from the top of the injectors for piece of mind we are on the right track.
You could try this if you have the tools http://www.bba-reman.com/content.aspx?c ... CUIT_FAULT
I've been thinking some more. The ECU might only fail on that cylinder when under load. The same as a poor connection. i.e. the poor connection could be in the ECU. I am assuming the LPG system doesn't load the circuit.
It may be possible to exclude the relay by careful tracing back of wires. It may be a case of unplugging the LPG wiring and plugging straight through for the injectors excluding the LPG loop. I don't know for sure.
Check the connectors and wire for green or white dust/ gunge. Usually at the connection between the wire and pin.
You could install a temporary wire between the injector and ECU but this would probably mean knackering your harness.
It is probably worthwhile trying to take a reading from the top of the injectors for piece of mind we are on the right track.
You could try this if you have the tools http://www.bba-reman.com/content.aspx?c ... CUIT_FAULT
I've been thinking some more. The ECU might only fail on that cylinder when under load. The same as a poor connection. i.e. the poor connection could be in the ECU. I am assuming the LPG system doesn't load the circuit.
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whoa, just a minute. Neither side of the petrol injector wiring should go to earth. One side gets switched to +12v when ignition on, the other side only gets taken to earth when the electronics inside the petrol ECU command a firing pulse.daveylitz wrote: same with other the contact to earth
You might see high-resistance readings there from the electronics, you might well see a different reading depending which way round you have your meter probes (that's a good sign).
When the injectors are plugged in, you might get feedback through the injector to the disconnected "+12V" line and through other devices connected to that (fuel pump, whatever) but the resistance cannot be lower than the 14 ohm injector winding value you read earlier.
If you see real low resistance to earth, there is a fault.
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