what's wrong that am I not seeing...

simon k · Post by **simon k** » Sun Sep 19, 2010 1:29 pm

hiya

I've been running an MJLJ on my mini for about 2 years, runs great, love it - my father is in to Morris Minors, and has one running dual fuel with LPG. I offered to install a MJLJ on it so that he could run a Petrol map and an LPG map. Good plan right.

So I soldered up a kit, made a loom and installed it this weekend. The bastard just won't spark - I've checked and re-checked every wire, and can't figure it out. I wired the EDIS to MJLJ loom with the same connectors as in my mini, and have swapped as much as I can between the cars, but unfortunately I have my engine in pieces, and can't compare voltages etc. which is a real pain.

I disconnected the MJLJ to rule out a fault there (putting the EDIS in 10* limp home mode). There is about 2.5V AC across the VR sensor when cranking, and I've tried reversing the connections - no good

The only thing that doesn't check out is that according to the Installation Guide, I should have 12V on pin 1 of the EDIS - I don't - but I've tried the EDIS from my mini and it's the same.

My boss offered me the little portable oscilloscope to bring home for the weekend, but I forgot to grab it

if anyone has any clues, I'd love to hear them

thanks

NITROPIXIE · Post by **NITROPIXIE** » Sun Sep 19, 2010 3:02 pm

What 12v suppy are you using for the EDIS and coil pack. I have known instances where people have taken from the wrong ignition position so when it cranks there is 0v going to it. It basically isolates all none essentia circuitry for starting so you get max current to the ignition system.

Is the car positive earth??

Are you using the coil wire for the coil pack. Is it resistive???

Failing that double check and recheck your wiring and you will find the problem

simon k · Post by **simon k** » Sun Sep 19, 2010 9:43 pm

nah, did all that Nitro...

Minors have a "manual" solenoid where you pull a cable that bridges the contacts, so only one ignition position. Voltage drop when starting is to about 9.5 volts, so that's OK.... It's negative earth, and I ran a wire direct from the battery to the coil to check the feed there

the only thing I did different to my car is earthed the sheld for the VR sensor cable

he lives 4 hours away, and came up for the weekend just to do this - he's gotta go home today

Spockie-Tech · Post by **Spockie-Tech** » Mon Sep 20, 2010 2:14 am

Process of Elimination - maybe Start at the spark plugs and work backwards.

Remove the EDIS and a couple of plugs. Clip-lead 12v to the coil pack, and tap the earth wire on the pin and see if you get a spark. If not, youve narrowed it down to the coilpack or leads (I assume the plugs are ok if he drove there)

Add the EDIS back in. (youve tried another EDIS module on his car, have you tried his on your car ?)

The 12v on Pin1 is the PIP (position indicator pulse according to some people) signal sent to the Megajolt, so if you are running in Limp Home mode, its absence may not matter, although it might indicate a fault with the EDIS. Ive never tested one to see if its at 12v without the Jolt connected.

What is important is the 12v power on Pin 8 (Assuming an EDIS 4), and a good ground on pin 9.

All the EDIS needs to run in limp-home mode is power on 8, ground on 9, the VR signal and the coilpack connections.

Try running a couple of seperate loose wires temporarily from the VR sensor to the EDIS.. dont bother about a shield for testing, a bit of possible noise wont stop it from starting. If it starts (or even kicks), then you return to the original shielded cable and if the problem reappears you know its the cable.

Finally, Kludgy, but if youre desperate - Either swap VR sensors, or.. park your working car next to his, take the plugs out of his and sit them on an earth, and run a long wire from your VR sensor to his EDIS. Crank your car and see if his EDIS sparks the plugs when triggered from your known good VR sensor.

Thats about all I can think of. Good Luck

simon k · Post by **simon k** » Mon Sep 20, 2010 2:48 am

thanks Spockie - my car is in bits, so I can't test things on it.. but your kludge suggestion of buddy breathing between the cars is quite a good one. Plugs and leads are all fine - I hooked his dizzy and coil back up and it started, it's just something the EDIS isn't doing. I've already put my VR sensor on his car, and my coil pack. I'll test the coil pack like you said, good suggestion

Dad has left his car with me and gone home on the bus, so I'll nut it out and then he can come and get it. He's in Ballarat, I'm in Wodonga...

thanks

NITROPIXIE · Post by **NITROPIXIE** » Mon Sep 20, 2010 6:54 pm

Shame you didn't get it finished on time.

Obvious I know, but have you wired the EDIS plug the correct way round?? As it is easily confused with the orientation??

12v to centre pin of coil pack?? Checked....

Full continuity check between plugs for VR and Coil pack to EDIS plug?? And then insulation test.

Good Chasis earth at the EDIS ground?? check EDIS earth continuity from EDIS plug to neg battery lead

Good engine earth?? (I'm guessing so due to starter motor cranking)

Any black rot/oxidation inside any wires???

Hard one this!!!!

ian2000t · Post by **ian2000t** » Mon Sep 20, 2010 11:31 pm

Is the VR sensor close enough? I had a prob with my Mini where it looked close enough, but kept misfiring - a quick look on the logs showed RPM values of 0. Moved the sensor closer and not one misfire 2,000 miles on! If it's "too" far away, it could be getting no signal at all... and hence it won't spark.

simon k · Post by **simon k** » Tue Sep 21, 2010 1:25 am

yep.... I've checked all of those things unfortunately! though I probably checked them in a hurry with dad looking over my shoulder

I'll relax a bit, and just systematically go through everything. I need to get my car back together first so I can give the loaner I'm driving back, then have something to compare dad's car with

thanks guys - I'm sure it'll be something silly

simon k · Post by **simon k** » Sun Oct 03, 2010 8:38 am

got back to it today with the scope from work, and everything checked out, the VR signal was OK, putting a 1k resistor from 12v to the coil output showed a nice pulse, but then when I did the same at the coil pack end of the loom there was nothing..... hang on - some idiot stuffed up the connector he'd put under the dashboard, and had the coil outputs going to pip/saw

so then it'd fire, but was backfiring and wouldn't run more than a couple of seconds - even though the coil pack has numbers on it for which lead goes to which plug - 2 and 4 were swapped over

sigh....

runs like a champion after that