kingbx95

Evening all,

First a little background...
I have recently built my s2 back up into another s2 shell, the car was previously running a zetec turbo on ofam (before I had it). I thought I'd take the opportunity to convert to efi as the engine loom was already there.

I have installed my 1.6 cvh turbo and ofab sensors using a trigger wheel setup and wired everything as per rabs diagram.

Now I have no spark and no fuel pump when turning over.

Fuel pump primes as it should

I have 12v at the three coil wires with ignition on

The cps (pins5+6 at edis) resistance is 400 ohms

Cps give approx 1v ac when cranking

When cranking the centre coil pin drops to 6-7v even with a decent 12v feed from the battery??!!??

I have a wire coming from pin 5 ECU that the previous owner has labeled a green1 but no ofab/ofac wiring diagrams

I'm really stumped now, initially I thought cps as I had no fuel pump when cranking and I can't hear the injectors at all.

Sorry for the long winded post, I'm at a real loss a to what to do now I have checked earths as there are none missing that I can see.

Any help greatly appreciated!

Cheers
Barney

Rob_DOHC

iTrader: (4)

Hey Barney. If the ecu connection to the EDIS unit was broken you would still have spark as the EDIS unit has a fall back unconnected 10deg advance failsafe.

This makes me think that the problem may be with your EDIS unit.... Have you checked you have 12v and a good GND going to the edis unit.

However that doesn't explain the fuel pump issue. Do you have 12V on one of the pins on the injector connectors?

I wouldn't be too worried about the voltage drop whilst cranking, 6-7 is quite low but not desperately unusual.


However,

If your EDIS unit isn't getting a good signal from the CPS you will have no spark, no injectors, no fuel pump (whilst cranking) so I would start here.

- The sensor could be faulty,
-The wire to the edis could be faulty
- The gap between the sensor and the wheel could be excessively large.


I suspect CPS or EDIS unit.

Hope some of that helps

Rob,

Rob_DOHC

iTrader: (4)

PS, is this car using the wiring loom OFAM was originally used with? Pin5 is used for the wide band lambda on the OFAM.

Rob,

kingbx95

Double post!

kingbx95

Thanks for the reply Rob.

Yeh it's Ryan's old loom, I was thinking last night that pin 5 was most likely ofam specific. Seems obvious really!

I have 12v and earth at te edis, I haven't checked the injectors with a meter yet.

Gap on the cps and trigger wheel is apprOx 0.8mm as it should be , how much tolerance is there on the 90 degrees btdc? Pretty sure it's reasonable close and I have adjustment in the bracket.

Is there any other way to test either edis or cps other than what I have already done? Getting pretty disheartened with it right now, may even juts rip the bloody loom
Out and start again!

Rob_DOHC

iTrader: (4)

Do you have access to an oscilloscope mate? That would tell you just about everything.

You can probably test the output of the EDIS with an LED, you should be getting pulses back to the ecu when cranking, and pulses to the edis from the ecu, SAW and PIP signals. One is 12v and the other 5v (square wave) so you will need to use a resistor 1K wouldn't be a bad choice.

When cranking pin 2 should also give a pulse, but only when there is spark.

But start with the CPS and work backwards. Just a silly question but your trigger wheel is 36-1?

You can reduce the 0.8mm gap a little and see if it helps. You can also try disconnecting the ECU from the EDIS making sure everything is still powered up. The EDIS should work without any ecu connection.

Rob,

Rob_DOHC

iTrader: (4)

Have you come across this website yet mate?

http://www.dainst.com/info/edis/edis.html

Just off out but ill check the thread later and see if i can think of anything in the mean time.

Rob,

kingbx95

Cheers Rob your a start mate!

No scope im afraid, yeh the trigger is a 36-1.at least i bought it as such cant remember counting it tbh.

its really doing me in, everything seems to check out. so a led and 1k resistor will help me test the injectors?is that correct?

im tempted to remove the engine loom and untape it all and see if there are any broken/damaged wires in there.

so do you think the CPS could be bfaulty even though i can measure some AC voltage from it when cranking, and the resistance of the circuit seems about right?

ill try your suggestions when home from work mate. away for a week from tomorrow would have loved to have it started before i went, ah well thats the joys of RS turbos i gesss.
i havent checked the coilpack output yet either.

kingbx95

Not come across that site either, will check it out.

thanks again mate

Rob_DOHC

iTrader: (4)

Hmmmm, its always really tricky diagnosing things over the net. Resistance of the cps does seem about right. 1V is a little low though which is why decreasing the gap 'may' help.

PS, the CPS or wheel being in the wrong place will not effect no spark. It will however effect how well the engine runs etc.

Normally the ecu primes for 1(ish)s and then enables the fuel pump when it syncs with the EDIS signal ie) see's and RPM. So i'm not surprised the fuel pump isn't running and the injectors aren't operating.

Where did you get your EDIS from? I probably have a spare that I can post to you to try if you like?

Rob,

mentalasanything

Resistance of the CPS should read 200-450 Ohms so that sounds right. Cranking you should see .5vAC with 1vAC spikes as the missing tooth passes (might be the other way round but you get the idea). There should be 0vAC when not cranking.

OFAB/OFAC has nothing in pin 5.

Mine would intermittently run with the original sensor I used as the gap was too big. I fitted one from a 1.6 Sierra with a .5mm gap and now it's faultless.

Lee

kingbx95

Cheers for that lee,
Everything you said makes sense and tallys up with the figures I was getting.

Although it seems that I may have cooked the ecu! And the quality of the loom is very questionable, so.....

It may well be time for megasquirt, get it done properly!
Thanks for all the help guys.