Engine Electrical Problem

[speedtripledan]

I've just been reading this http://www.megamanual.com/ms2/EDIS.htm about the EDIS system.

 

Does the problem exist if the engine is in the "limp home" configuration ? I.e if you disconnect the megasquirt PIP/SAW signal ?

 

I'm wondering if those cable need shielding from external interference.

 

Simon.

tried that no change

[richardm6994]

Cheers for looking Simon.....have you also heard what the prize is for the person that solves it (without swapping to a dizzy)

The pip and saw cables are shielded.

 

That's how we've eliminated the megajolt unit because the fault still happens in limp home mode.

[speedtripledan]

don,t mind which box of beer i,m not fussy

[philshelton]

Found a solution for you Richard. Take it all out and give it to me in exchange for my pinto :rofl: :rofl:

[richardm6994]

Mark, on saturday I'll be bringing.....

 

new crank sensor and new plug

2 new coil pack plugs

6m of new shielded cable

new megajolt plug with new pins

new coil pack

spare edis8 with plug

5 or 6 reels of wire (different colors)

Soldering stuff and heat shrink tubing

 

 

If needed, we could rewire the entire ignition system......and if this doesn't work....gas-axe!!!

 

fingers crossed

[Snapperpaul]

I'm betting on coil pack plug or coil pack wiring to EDIS

[speedtripledan]

Mark, on saturday I'll be bringing.....

 

new crank sensor and new plug

2 new coil pack plugs

6m of new shielded cable

new megajolt plug with new pins

new coil pack

spare edis8 with plug

5 or 6 reels of wire (different colors)

Soldering stuff and heat shrink tubing

 

 

If needed, we could rewire the entire ignition system......and if this doesn't work....gas-axe!!!

 

fingers crossed

And Dan

[Guest zerorace]

i am betting on not ignition fault now

[Guest MarkB]

I reckon that should cover it Richy

[Snapperpaul]

Megajolt run time data would show issues

I noted back fire points by acceleration data when the VR sensor wire in the plug was breaking down

Might be worth running the log sheets past Autosportlabs forum

[richardm6994]

i am betting on not ignition fault now

 

Me to.....dan and I have spent hours analysing the ignition and replacing various components.....so it's bound to be something simple elsewhere that we've just overlooked!

Well that's what I'm hoping anyway

[speedtripledan]

Random thought and prob a load of bullwax but: Would having a worn positive wire, somewhere away from where you've been looking, rubbing on the chassis and sometimes putting 12v though it and maybe killing some earth temporarily be a possibility?

thought of that

[sj-bradley]

The site I read up on mentions 25 uF capacitors on the 12 volt line into the coils. These are there to suppress spikes from the back emf.

 

The only real way to see if these are needed is to see on a scope if the 12 volt supply is smooth. If not, it could be affecting the EDIS by putting a large spike back through it.

 

If you can get hold of some 22 or 47 microFarad uF capacitors, you could try putting them across the 12 volt line and ground (note if your use electrolytic ones that you wire them the right way round. They are polarised and if you wire them up backwards, they tend to explode !) Bigger uF values are better than smaller.

 

They are not expensive (like 10p or so) and might help.

 

Simon.

[Guest peter2b2002]

just a thought, years ago i had a very intermittent miss fire, on my 1st rangy, had it in the garage doing some thing under the bonnet whith the engine running when there was a power cut (lights went out) when i noticed a faint blue streak from one of the wires going to the the dizzy , moving the wire close to the manifold there was a spark that caused the miss fire , seems the insulation on the wire had broken down , it was not a HV wire only a 12v feed, try looking under the bonnet in the dark

peter2b

[richardm6994]

First of all I would like to say a big thank you to mark and dan for sorting out this problem today.

 

It turned out to be a edis wiring issue....

 

 

This is the diagram I used for wiring the edis...as you can see the shielded cables (vr and megajolt) is connected to pin 7 of the edis and also ground.

 

This is the diagram I should of used....as you can see, there is no connection between pin 7 and ground.

 

It was this connection between pin 7 and ground that was causing me all the problems.

What we did was cut the pin 7 wire and ran the shield directly to ground....and problem solved!

 

 

All that I need to do now is take it for a drive to make sure the problem is gone for good!