LPG Forum


All times are UTC



Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2  Next
Author Message
PostPosted: Mon Aug 27, 2018 7:14 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
I'm in the process of swapping my ecu and wiring to a Stag 4 Eco". The wiring diagram shows a coil connection. Can anyone confirm where this connection connects on a corsa c with a 4 way col pack
Thanks


Top
 Profile  
Reply with quote  
PostPosted: Mon Aug 27, 2018 10:06 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
One of the signal wires - easiest bet is to take your multimeter and test for voltage on the pins, you want one of the wires that doesn't have voltage with the ignition switched on. Assuming this is the rpm feed that is. Might help to confirm the colour of the wire your trying to connect from the Stag side.


Top
 Profile  
Reply with quote  
PostPosted: Mon Aug 27, 2018 10:10 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
If it's a 6 wire coll pack could do any of the 4 coil trigger wires (not earth and not +12v) or if 7 wires the extra wire (like an inducted spark wire) can also work.

Crossed with Bri's post.

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Mon Oct 01, 2018 7:06 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
Thanks for the info, got the car switching over to gas but when I try to run the auto calibration it starts on cylinder 1 attempts to get in synch with petrol injector and then the ecu switches the no 1 petrol and gas injectors off so both show in time of 0 ms. It then moves to cylinder 3 and attempts to sync while running on 3 cylinders. Part way into this a message comes up on the screen about gas pressure.
The only way to get no 1 back is to switch off and start again. Tried this a few times with same result so can't see it being a dodgy relay in the ecu. The injectors are +ve driven stag 4 states that Eco ecu doesn't cater for this arrangement. Any advise or guidance would be greatly appreciated
Cheers
John


Top
 Profile  
Reply with quote  
PostPosted: Mon Oct 01, 2018 7:21 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
How have you got them connected to the petrol injectors (which side of the injector and which way round to the wires from the stag unit - might be eaiser to take photos and link to them on here).

If they are positive driven and the ecu doesn't support it (don't know if thats the case on either point, but sounds like you have found it is) then the only option you'd have is using an ecu that does support positive switching. But it would be a good idea to confirm why you think thats the case unless someone else can confirm it is correct.


Top
 Profile  
Reply with quote  
PostPosted: Mon Oct 01, 2018 7:42 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
They are connected with the single colour (say yellow) to the petrol injector and the yellow and black from the petrol ecu
Seems strange that the car runs on gas albeit rough with the +ve driven injectors and only acts up when trying to calibrate.


Top
 Profile  
Reply with quote  
PostPosted: Tue Oct 02, 2018 10:32 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
The injectors on a Corsa C are not positive driven. It would seem you have done the petrol injector breaks on the wrong side of the petrol injectors

If injectors were positive driven and you fitted an ECuU that didn't have facility/setting to work with positive switched injectors there would be no cure other than to fit a different ECU anyway (other than messing about with a lot of unnecessary electronics).

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Wed Oct 03, 2018 9:04 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
I'll check it out again tomorrow, as I said earlier the issue I seem to have is the ecu switching the petrol injector off during calibration. Any idea on issue. Should I be selecting all together for the injectors ?


Top
 Profile  
Reply with quote  
PostPosted: Wed Oct 03, 2018 9:26 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
If you have anything like correct nozzle size and pressure and if you have correct routing (gas injector 1 corresponds to petrol inj 1 and so on) you shouldn't need to select 'all at once' in software on this engine. If 'all at once' makes things a lot better, check routing.

But as said, I think your biggest problem is selecting positive controlled injectors. If your nozzles and/or set pressure are woefully too small a combination then selecting positive controlled injectors could see more like expected results during initial phase of autocal than the proper (negative injectors) setting.... but only because during those conditions the effects of the two issues cancel each other out to some extent. If you have both issues the cancelling out would only work during the low load idle conditions, you'd never calibrate it properly for the full dynamic range of the engine like that. Well... maybe I could... but you can't lol. Untick positive injectors and tell us what nozzles and pressure you set.

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Thu Oct 04, 2018 5:56 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
You're absolutely right the injectors are -ve and that's how they are connected. I've checked the routing pipes and wires and all are correct. Nozzles are 2.3 mm. The pressure was around 1.2 bar. I haven't got the lambda connectied does this go to black on the O2 sensor.

Cheers


Top
 Profile  
Reply with quote  
PostPosted: Thu Oct 04, 2018 6:09 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
I wouldn't bother with the lambda connection its unlikely to provide any useful info and won't actually stop anything working on a sequential setup, its just there to display the lambda in the software. You would do better to monitor the fuel trims via the obd port if you can do so.

To answer what wire you want it to goto depends on the sensor thats been fitted, Black is signal on some but not all sensors. This might help
http://www.lambdasensor.com/main/mcolours1.htm

Otherwise what colours are there and how many of each? typically 2 wires the same colour are the heater circuit if that helps, but as you can see from the link there are a couple of possible options. Your also best to connect to the loom of the car, not the sensor itself as if you connect to the sensor you then have to break the connection if you need to replace the sensor (and the wire on the sensor flylead is usually impossible to solder to, I think its stainless steel so the solder won't stick)


Top
 Profile  
Reply with quote  
PostPosted: Thu Oct 04, 2018 6:48 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
I've got two white cables that are the heater. There is also a grey cable that is down to earth on the harness side. I'll not bother connecting tha lambda.
I'll try the calibration again at the weekend seems odd that no 1 petrol injector switches off. They are all pretty constant at 3.1 ms at idle


Top
 Profile  
Reply with quote  
PostPosted: Thu Oct 04, 2018 7:20 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
It would be the black one in that case as you suspected. If your only seeing it on injector 1 that would suggest that you have the injector cut done with the wires switched over (it will show a reading till you try to switch in that state, which is what you describe). If you try manually switching the rest and they work as expected, it only really leaves either the wiring isn't right, or the ecu has failed on that channel. The first option being more likely than the second. Is this a new ecu or used one?


Top
 Profile  
Reply with quote  
PostPosted: Thu Oct 04, 2018 10:05 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
Good advice about the yellow / yellow with stripe wires being mixed up / and about could be an LPG ECU issue if that isn't the case.

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Sun Oct 07, 2018 4:28 pm 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
Checked the connections and they are correct so it looks like the ecu might be shot. Does anyone by any chance have a stag 4 eco or 4 plus ecu in the shed for sale that they know is working.


Top
 Profile  
Reply with quote  
PostPosted: Sun Oct 07, 2018 4:40 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
Is it a new ECU/Loom or a used one? If its used then just a thought on this, it might be worth tracing the wires back in the loom first - either check end to end with a meter, or pop them out of the covering and check they haven't been swapped over, if someone has wired it up previously and got the wires reversed they might have swapped them over at a more accessible location to sort it. Might not be obvious you'd do so given the accessibility on your current engine, but if you've no idea what it was on previously that might not have been the case on the original install.


Top
 Profile  
Reply with quote  
PostPosted: Sun Oct 07, 2018 5:29 pm 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
Agreed with Bri.
The Stag ECU's do tend to go wrong in the way of dud injector channels though.

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
PostPosted: Mon Oct 08, 2018 10:47 am 
New member

Joined: Wed Apr 03, 2013 5:38 pm
Posts: 60
It's a used unit so I'll check the harness to see if there's any tape on it but also back at the main plug. I suppose I could swap th over and try the calibration again. I checked the polarity at the injectors and the +ve is only live with engine running, engine runs fine, does this sound correct


Top
 Profile  
Reply with quote  
PostPosted: Mon Oct 08, 2018 7:57 pm 
Intermediate Member

Joined: Mon Jan 23, 2012 12:21 pm
Posts: 1058
Images: 1
Location: Milton Keynes
That does sound about normal, most setups use the negative to pulse the injectors and supply a common positive to them. If it was positive switched then you'd have found some info on here on it (and Simon would know anyway) as its not like the first Corsa anyone has ever converted to lpg.

Simon may know if the Stag loom will match up with a different brand of ECU, Stag don't have the best of reputations and that might make your serach easier if your happy the loom isn't the cause (of course, it might be easier to just swap the yellow wires over to being the wrong way round and seeing if that fixes it if you can't be sure it hasn't been messed with, there must be a link there for it to run ok on petrol, if either side was broken you wouldn't be able to get it to run normally).


Top
 Profile  
Reply with quote  
PostPosted: Tue Oct 09, 2018 9:28 am 
Installer

Joined: Wed Sep 29, 2010 5:01 pm
Posts: 3210
Location: Yorkshire
There have been a few incarnations of Stag 4's, some metal cased ECU's some plastic, they use a different ECU connector plug (so plug pinout is besides the point if the plug won't even fit the ECU). If the plug will fit, though, then (in case of Stag) pinout should be the same. I notice LPGShop are selling factory refurbed Stag4 ECU's for £30, I imagine most refurbed ECU's will have had the problem of broken channels (which yours may have suffered) - I doubt it would be economical for them to replace chips etc on the ECU board but when Stag ECU's suffer broken channels the problem seems to be due to broken relays on the ECU board and relays are far easier to swap out on boards than chips. A lot of years ago I fitted quite a few Stags, around 1 in 7 ECU's arrived broken when new, more failed (relays) during calibration. It probably isn't coincidence that the only ECU type the supplier lists as available as a refurb is Stag. But I had thought they'd addressed the problem.. Perhaps it's mostly just older Stag ECUs that still have more than their fair share or this type of problem.

Maybe help clear up confusion about negative / positive controlled petrol injectors... If the injectors are negative controlled they receive a negative pulse and have a constant positive (when the engine is running) on the other wire, this is the normal setup. If the injectors are positive controlled they receive a positive pulse and have a constant negative on the other wire (with the engine running). In fact if the vehicle has negative earth (battery negative connected to vehicle body) the constant negative may be truly constant even with ignition off because the injector negatives may be wired straight to earth.

If you use a multimeter to check voltage on a negative pulsed (normal setup) injector with engine running (or ignition on for a while) you will see 12v on both sides of the injector... One wire is the 12v constant feed so you read the 12v feed on that wire directly. The other wire also reads 12v because the 12v from the constant feed wire passes through the injector's coil winding (same as it would pass through any electrical resistor, in the case of a petrol injector the resistance is about 15ohms). The only times (very brief moments) when close to 0v will be read on the pulsing side of the injector are during when the injector is being pulsed. But if the engine isn't running the injectors are not being pulsed at all so the negative pulse wire will be constantly at 12v; Even if the engine is idling at say 600rpm (600rpm used for simplicity) if the injectors are only pulsing for 3ms every 2nd engine rotation (2nd rotation because the engine is a 4 stoke) and an engine rotation takes 1/10th of a second at 600rpm so every 2nd rotation takes 1/5th of a second which is 200ms, the pulsing wire of the petrol injector is only pulled to earth for 3/200ths of the time (a duty cycle of 1.5%) so 98.5% of the time there will be 12v on the negative wire. Different model digital multimeters will react differently to varying voltages (12v no pulse, 0v pulse), some will show a constant figure of very near 12v (more really with the engine running due to alternator charge), others will occasionally show a slight flutter of variation, it depends on the sampling rate of the meter. On the flip side of this (negative pulsed injectors read 12v on both wires most of the time), positive pulsed injectors would read 0v on both sides of the injectors most of the time - So you reading 12volts says it's negative pulsed. On most negative pulsed injector engines you'll read the constant 12v to injectors for a while as soon as ignition is turned on but other engines only get the 12v positive on injectors during engine run or engine crank conditions and are quick to turn off the 12v when the engine is stopped/stalled.

If you see near 12v on injector wires at all without the engine running the injectors will be negative pulsed.

_________________
Full time LPG installer
Servicing / Diagnostics / Repairs to all systems / DIY conversion kits supplied with thorough tech support
Mid Yorkshire
2 miles A1, 8 miles M62,
http://www.Lpgc.co.uk
Twitter https://twitter.com/AutogasSimon
07816237240


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 23 posts ]  Go to page 1, 2  Next

All times are UTC


Who is online

Users browsing this forum: No registered users and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
cron
Powered by phpBB® Forum Software © phpBB Group