New ECU won't fire injector problem me thinks

[adyw]

Gents,
I need you help, for the last week I have been with regards my new Megasquirt with edis 8 installation. The short version the car would not start. I have narrowed it down to the main relay not turning the injectors on, So with a temp fix ( e.g a jumper wire stuffed into the +12v) I then tried the car again.
This time it splutters and I can finally smell petrol on the end of the spark plugs. On investigation I found that I am getting +12v on the 1,3,5,7 injectors on one of the electrical pins. But +12v on both pins on the 2,4,6,8 injectors, Is this right as I think one is not correct hence the reason why it splutters.
Any body have a guess for the reason why ?

[Loubaruch]

It sounds as though only one bank of cylinders are getting pulses. To check if pulses are present you need a lucas injector harness checker or similar see:

http://bertram-hill.co.uk/tvrs3.aspx

Simply measuring voltage is not a very reliable method.

I experienced a similar problem with my 500 after fidding with the ECU loom it turned out to be a faulty connection at the ECU socket feeding the nearside bank of injectors, a wire had pulled out of its connector.

Be careful measuring around the ECU it could prove expensive, better to unplug the ECU before checking continuity from ECU plug to the injector bank.

My car:
Injector bank Cylinders 2 4 6 8 connected to ECU pin 11
Cylinders 1 3 5 7 pin 13

As per bible

Edited by Loubaruch on Friday 11th July 22:21

Edited by Loubaruch on Friday 11th July 22:23

[adyw]

thanks, tried that nothing loose in the back of the plug

[GreenV8S]

The symptoms seem to suggest that you have a good +12V feed to both injector banks but only one side is being pulled down by the ECU. This could be because the ECU isn't configured correctly, or because the injectors aren't connected to the ECU correctly. Are you intending to use two injector outputs, one per bank? Does the ECU configuration reflect this, and do you see the same duty cycle shown for both injector outputs while cranking?

Have you done a continuity check of the loom to make sure the things you expect to be connected, are? Did you make the loom yourself? No offense meant to however made the loom, but the wiring fault you've already located makes the presence of other faults more likely in my mind.

Edit to add:

When you took your measurements, was the engine running/cranking? At rest with power applied the injectors should all be closed and this would result in 12V on both sides (+12V feed to one side, the other side floating up to 12V).

Edited by GreenV8S on Saturday 12th July 10:03

[adyw]

Hi
the injector loom is the cars original, all I have done is to connect my new ecu into the multi pin plug with injector inputs to the ecu on pins 11 and 13. And the original power supply from the main realy is still used.
The readings I have taken are with the ingintion on but not craking.
2,4,6,8 12v both pins
1,3,5,7 12v one pin and I know these are working as the plugs are wet.

what is strange is if I disconnect the battery and put a power source on the main relay feed power supply to the injectors I get 12v at say pin A on the injector plug.
If I do the same thing this time on the pin 13 on the ecu plug I get 12v again on injector pin A, something is not right. I have check the inside of the multi plug to see if something has come loose so I am now stuck for ideas

[GreenV8S]

I haven't followed all that, I'll have to look up the pin-outs to make sense of it.

Do you understand how the injector circuit is supposed to work? If so, what is your understanding?

[trackcar]

Does that not suggest a short between the power feed and the earth return back to the ecu from that bank of injectors? If you didn't remove teh plug to the MS ECU when doing this test it could be an internal fault in the ECU? Admittedly I'm no electrician but to be honest if i was struggling I would take the original wiring out for the injectors and make a new loom up, that way you know the wiring is of good quality, with no shorts and you should then have no problems. I hope!

[adyw]

Ok,
my understanding is that all injectors have a 12v feed.
then I am not 100%, it is either the other pin has 12v and the ecu turn it on and off to activate the injecotrs. Or
it is a pulse from the ecu to the 0v pin and activie the injectors

which one is correct ?
I could be looking at the wrong bank and infact the other bank is permantly on.

[Loubaruch]

Have you tried re connecting the original ECU to see if the fault remains? If not then there is a problem with your new ECU.

If the fault is still there with the original ECU then something has changed, It could be the ECU socket,the plug/sockets to the injectors or maybe the loom.

As suggested by GreenV8S have you checked the continuity of the loom from ECU pins 11 and 13 to the injectors?

Edited by Loubaruch on Saturday 12th July 22:28

[GreenV8S]

The way it should work is the injectors have 12V fed to one side, and the other side is earthed via the ECU to turn the injector on. Obviously, the injectors are only supposed to be pulsed open while the engine is running. You should never find the injector permanently on, and you should never find it on while the engine is stopped.

To start with I suggest you confirm that the loom is wired correctly and that you understand it. Disconnect the connectors from all the injectors and unplug the ECU, test the voltage on each terminal of each connector and confirm that with the ignition on you have permanent 12V on one terminal and nothing on the other. (I *think* it's ignition switched rather than turned on with the pump, but if you don't see 12V you might need to hotwire the relay that powers the injectors.) You should also have a connection between the other terminal (the one without 12V on it) to pin 11 of the ECU plug on one bank and pin 13 on the other.

Once you've confirmed the external wiring is sensible, see what the ECU is doing while the engine is cranking over. Stick a test lamp across one of the connectors, crank the engine over and confirm that the lamp flashes regularly while cranking. Then do the same with a connector on the opposite bank. Make sure you use a small bulb to avoid overloading the injector driver, I use 12V LEDs but any low wattage bulb would be OK. I suggest you disable the fuel pump while you're doing this to avoid flooding the engine.

Your description suggests you're getting different behaviour on the two banks. If you get sensible behaviour from one bank and not from the other, I would suspect either the wiring between the 14CUX plug and your MegaSquirt, or a configuration fault on the MegaSquirt.

[Pupp]

If you haven't seen this thread, it might be worth a squint; if only to appreciate you're not the only one that's trod the path!

grief

[adyw]

thanks gents,
tommorrow is another day

[cinquecento]

Adrian

Q9 and Q12 ground the - side of bank 1 and bank 2. You can swap wires to see if the problem moves to the other bank. This would elimate any h/w error. To test my MS, I got 2 injectors from the wreckers and as they are high impedance injectors, you can wire them directly to 12v and to pin 32/33 and 34/35. The injectors should pulse as Q9 and Q12 ground the - side.

Hope this helps

Edited by cinquecento on Sunday 13th July 03:49

[adyw]

I think my main problems are one bank is permantly on and one bank is working as normal, am I missing some setting in the MS ecu,

[adyw]

AAAAAAAHHHHHHHHH,
here's a started for 10 on a sunday morning.
with old ecu plugged in, the volts on both pins on both banks of injectors is +12v
so by my estimation that means my new ECU is leaving one bank permantly on.
just think of the fuel consumption if it started.
All I have to find now is the setting in the ecu for this.

any ideas on MS1 before I spend all day looking.

[GreenV8S]

Suggest you check that they're wired correctly between the ECU connector and the MS - or ask the person who made that part to check it.

Also (from memory - I'm running a very different injector configuration now) you should have the second injector output driven from VE1 with 'alternating' output selected and 2 injection events per engine cycle (or some multiple of 2 would probably work too).

Edited by GreenV8S on Sunday 13th July 11:14