AC Stag-4 Eco coil Connection

Just fix it
New member
Posts: 60
Joined: Wed Apr 03, 2013 6:38 pm

Re: AC Stag-4 Eco coil Connection

#21 Post by Just fix it » Tue Oct 09, 2018 8:24 pm

I'm near certain that the injectors are negative pulse. The positive is only present with engine running. This is probably how I got the polarity crossed at first ie tried to find the positive without engine running and assumed it was the negative.
The failed relay/loss of supply to petrol injector issue only seems to arise under calibration. What about if I swap cut injector wires and Lpg injector feeds over between cylinder 1 and say 3 and see if cylinder 1 still shuts down under calibration. Does the ecu look for pulse in and give the corresponding pulse out.

Intermediate Member
Posts: 1309
Joined: Mon Jan 23, 2012 12:21 pm
Location: Milton Keynes

Re: AC Stag-4 Eco coil Connection

#22 Post by Brian_H » Tue Oct 09, 2018 9:09 pm

As long as you switch both it shouldn't matter which cylinder is which, but I'd suspect you will find it will be the channel on the ecu at fault it will still be a problem if your trying to autocalibrate.

If you use the bit on the righthand side for the injectors to switch 2/3/4 on do they switch correctly? What does injector 1 do in this state does it switch correctly? (it may not run particually well as its calibrated to something, but we don't know what that something actually is to say if its even a good match, but that doesn't matter at this point).

If you get the same thing happening there then its either your injector wiring/loom, or the ecu is just dead on that channel. Any of those is a likely cause really.

Did you manage to check the wires yet? If you can take a decent photo of the wires if your in any way not sure where you have connected to and post it here that would help rule some of the possible bits out, its a long shot on the wires being swapped as the injector looms on 4 cylinder engines are usually fairly easy to access, so if someone had wired it wrong they would probably swap it at the original cut points. Some engines its a right pain to access the injector wiring. Thor V8s for example due to the manifold needing to be removed to get to it.

Posts: 3474
Joined: Wed Sep 29, 2010 6:01 pm
Location: Yorkshire

Re: AC Stag-4 Eco coil Connection

#23 Post by LPGC » Wed Oct 10, 2018 10:08 am

What version of Stag software are you running? In the Autocal screen, if it has an 'injectors at once option' tick that option.
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,

Post Reply