• Hello Guest, welcome to the initial stages of our new platform!
    You can find some additional information about where we are in the process of migrating the board and setting up our new software here

    Thank you for being a part of our community!

Wasted spark (ish) problem

K9 240

Member
Joined
Jun 26, 2013
Location
Midlands UK
Hi everyone
I have a na '93 240 with LH 2.4
I fitted the Buchka wasted spark board some time ago which has worked without any problems.
I have made other mods - moving the battery & washer bottle to the rear butt cheek, TLAO chips, turbo ECU 's, larger injectors & larger AMM / Tb, all in preparation for going plusT.
Everything has been working well and the time has finally come to fit the turbo and tidy the wiring from having lost the coil & moved the battery etc.
I disconnected the plug from the original ignition module (bosch MTR 0227 100124) when I lifted the engine to remove the sump pan. I did not reconnect it when I started the engine again and it ran ok. As the car ran without the old module being connected I assumed the wire to it could be done away with. The plug to the module contained two wires which had come from the removed coil, a black wire and a shielded wire, the shielding being connected separately. I started the car to make sure it still ran and with the engine off I cut the remaining two wires. When I tried the car immediately afterwards it didn't want to start & ran badly. It would not start at all on further attempts. I checked for continuity between the wires on the bit I had cut off in case they were joined at the plug somehow, but nothing. I joined the wires back together and the car started! I can't work out how joining on an extra 18 inches of wire can make a difference. There doesn't seem to be anything in the plug itself either.
Can anyone explain what's going on?
Has anyone else who has added wasted spark had this problem or similar?
 
I'm having some trouble following along with your post.

Where exactly did you cut the wire and shield?

Was the ignition module still disconnected when you joined the wire and shield again?

What do you mean 18" of wire? Isn't your original ignition module on the intake-side strut tower?
 
Hi Karl
Thanks for the interest.
The old ignition module (124 module / 124 power stage ) was situated on the inner wing on the inlet side just behind the headlight. This is a UK model. The lead going to it came from the mass of wires under the inlet manifold. The red/white & blue wires joined it from the old coil area.
I cut the two wires about 4 inches from where it joined the rest under the manifold. The cut off bit was about 18 inches long & attached to the plug that fitted on the module.
The module had not been connected to the plug since I started the car after adding the turbo. The car ran fine without the module connected which is why I thought I could cut the wires. There is no discernible difference to the running of the car whether or not it is connected. At the moment I am running the car with the re - attached plug just tied up.
 
When you cut the wire, was the inner conductor shorted to the shield? If the two were connected then you definitely wouldn't get any spark. Your best bet for eliminating that wire is to remove it from the EZK connector.
 
The shield would have shorted when I cut the wire but the car was not running or even switched on at the time.
I'll try removing the wire from the connector as you suggest.
Thanks, Tim
 
Result!!! :):)
wire removed from EZK (terminal no 16 on the plug)
Car started ok & was able to remove the cut piece of wire successfully!
Having thought about it, the po had an immobiliser/alarm fitted. I haven't used it but when I fitted the spark board & chips it was obvious the loom had been messed with. Could be something to do with that.
Anyway, thanks again for your help - I'm off to road test my plusT installation. (My laptop has died & this stupid tablet does not have a plus symbol).
Tim
 
Back
Top