Any megasquirt gods can you help.....

[neal1980]

Hi Ive fitted a megasquirt 1 extra pre built and Im getting no spark. Its on a rover v8 engine using a 36-1 wheel, ford VR sensor, 2 X Ford coil packs. Im getting No spark from any lead at all. I have done the following checks can anybody help please...

1) Confirmed power to coil packs and a very good earth (battery)
2) Checked VR Sensor is 0.75-1mm away from wheel
3) I am getting RPM in megatune when cranking
4) I have set the crank wheel to no tooth 5 and using the following settings:

Trig Pos A 35
Trig ReturnA 4
Trig Pos B 8
Trig ReturnB 13
Trig Pos C 17
Trig Return C 22
Trig Pos D 26
Trig Return D 31

I have made sure it megatune that im using generic wheel and I have the four outputs set correctly Spark A B C D.

Any idears please, thanks for taking time to read.

Neal

[BB-Q]

Just going from memory, have you got a power supply to the coils? And have you checked to see if you are getting a switching voltage during cranking?

[eliot]

Sounds about right. The basic concept is that the VB921 inside shorts the negative side of the coil to earth. So on each of your "spark outputs" on the ECU, you should actually see 12v - because 12v flows straight through the coils and INTO the "OUTPUT" of the ECU, which then shorts it to earth via the VB921's
Who sold you the ECU? (please dont say mtech)

[GreenV8S]

I would start by disconnecting the coil packs (if not already disconnected) and fit a test lamp across the connector. This way you don't need to worry about blowing up the coil pack or driver while you figure it out.

I'm not an expert but the toothed wheel settings look credible to me. I assume you have the extra coil drivers and separate connector on the ECU case and separate earth lead for the ignition. When you refer to a good earth, is this the earth you mean?

PS your MS installation sounds superficially very similar to mine. I got mine from Phil Ringwood and found him extremely helpful when I was setting it up.

For reference, my setup is:

36-1 Ford MVR sensor, 2x Ford twin coil packs.

Cranking timing = trigger return.
Wheel decoder 025 style.
Trigger Angle 60 (to suit my sensor orientation - yours would vary)
A Trigger 6
A Return 11
B Trigger 15
B Return 20
C Trigger 24
C Return 29
D Trigger 32
D Return 38

I remember that it took me a while to get that right due to having already fixed the crank sensor in the 'wrong' place. It also took me a while to figure out what those numbers all meant, it wasn't particularly obvious from the instructions until it suddenly clicked that during cranking the 'toothed wheel' logic tries to emulate an optical pickup which turn the coil 'on' at the trigger angle and 'off' (to generate a spark) at the 'return' angle. Once it's running it goes back to the more obvious timing based on the mapped offset from the trigger angle.

Edited by GreenV8S on Sunday 20th January 17:09

[neal1980]

Ive just pulled the connector off one of the coil packs and im getting approx 18V on the power wire then it gradually dies down..... ???

[neal1980]

I also do not see any voltage from the 4 outputs at the coil pack end with the connector pulled off and the ignition on. Does this sound right or should I only see voltage there on cranking?

Thanks
Neal

[GreenV8S]

Can you describe how your coils are wired?

I'd expect to find a single 12V supply to the center pin on each coil pack, and two wires from the outer pins back to the ECU (4 wires total to the ECU), then an earth out of the ECU to a good earth point (I think the engine block is the best place but IMO good idea not to use the same earth point as the main ECU earth).

Edited by GreenV8S on Sunday 20th January 17:17

[neal1980]

Ok well I just used the diagram from Extraefi. Using 2 ford coilpacks, from the ECU I believe the coil pack drivers etc are all built in. Theres a connector that comes out the ecu with 5 wires, 4 x outputs and an earth. I have connected the earth to the battery and on the ford coilpacks I have the 4 wires going to these. Then I have put a switched ignition feed to the coil packs as well. Hope this makes sense. I have the diagram here.

[GreenV8S]

neal1980 said:

Ok well I just used the diagram from Extraefi. Using 2 ford coilpacks, from the ECU I believe the coil pack drivers etc are all built in. Theres a connector that comes out the ecu with 5 wires, 4 x outputs and an earth. I have connected the earth to the battery and on the ford coilpacks I have the 4 wires going to these. Then I have put a switched ignition feed to the coil packs as well. Hope this makes sense. I have the diagram here.

Sounds right.

You should have battery voltage on the centre terminal of each connector. The outer two are floating most of the time (so if they're plugged in to the coil a voltmeter will see 12v here being carried through the coil) and the ECU pulls them down to earth to energize the coil and then disconnects them (so they are floating again) to generate the spark.

[neal1980]

mmmm..well I will plug them in now and see if i can get a volt meter to confirm this. Only other thing that I can think of is my ability to make spark plug leads might be crap! I cut the ends off and crimped them to existing rover v8 leads. Could be a record if all 8 are not working!

Thanks

Neal

[neal1980]

Ive just checked and I have 18V going to the output side either side of the power cable on the connector with it plugged in.

[GreenV8S]

neal1980 said:

Ive just checked and I have 18V going to the output side either side of the power cable on the connector with it plugged in.

That seems unlikely unless you also have 18V on the switched ignition supply to the middle terminal. And I can't think how you'd manage that from a 12V battery. As a sanity check, what voltage do you get on the battery, and what voltage to the middle terminal on the coil? If you are using a digital meter check the battery - when these go flat you can often get wildly inaccurate readings.

[eliot]

GreenV8S said:

neal1980 said:

Ive just checked and I have 18V going to the output side either side of the power cable on the connector with it plugged in.

That seems unlikely unless you also have 18V on the switched ignition supply to the middle terminal. And I can't think how you'd manage that from a 12V battery. As a sanity check, what voltage do you get on the battery, and what voltage to the middle terminal on the coil? If you are using a digital meter check the battery - when these go flat you can often get wildly inaccurate readings.

Indeed. Get yourself a digital meter from Mapins, less than a tenner - and if you have one - check the battery. You should only have around 13v.
Check that the 12v to the coils is still live when cranking also.
You didn't mention where the MS came from and a big assumption - is that it has actually been modified internally to support 4 coil packs. With the cover removed, you should see 3 extra ignition drivers (VB921) bolted to the case - with a load of wires going back to the proto area.

[GreenV8S]

eliot said:

You didn't mention where the MS came from and a big assumption - is that it has actually been modified internally to support 4 coil packs. With the cover removed, you should see 3 extra ignition drivers (VB921) bolted to the case - with a load of wires going back to the proto area.

The supplier would be the first person I'd go to for help if it was me.

But surely, barring some horrible mistake, the presence of the extra ignition connector with the right number of wires shows that the unit is intended to support the four coil setup.

[neal1980]

It came from Phil Ringwood, Extraefi.co.uk if this makes the setup easier to understand. I will get a new volt meter today and test when I get home.

Thanks for the advice so far people

[deetes]

eliot said:

(please dont say mtech)

Funny you should mention this company. I bid for a connector, on ebay, from them and won it. This was on the 17th of December. Still not received it yet. Seen a few bad oppinions of them on Megasquirtmaps forum.

I'm in the middle of converting my TVR to wasted spark, as well, so I haven't wandered to far off the thread.

Bought my MS from Phil Ringwood and he's quite helpful, but realy difficult to get a hold of at times.

[bertelli_1]

Aren't mtech & megasquirtmaps the same people?? I had a response from Jac (mtech) to the bad feedback they are getting. In their defence they sound quite sincere, will fix any faulty units & have promised to 'up their game' in the future. Time will tell I suppose....

[eliot]

bertelli_1 said:

Aren't mtech & megasquirtmaps the same people?? I had a response from Jac (mtech) to the bad feedback they are getting. In their defence they sound quite sincere, will fix any faulty units & have promised to 'up their game' in the future. Time will tell I suppose....

Ive seen inside one of their ecu's, not great. Stick to the auth sellers detailed on the MS forums, last thing you want to be doing on a new install is wondering if you have bought a pup.

[ihatesissycars]

Are the coild driven directly by the MS?

I had a very similar setup and no matter what I tried I could not get the coils to fire via the vb921's despite the coils checking out and the vb function checking out and wthe wiring etc.

In the end I switched to an EDIS setup which worked great.

[neal1980]

Yes I will be driving the coils directly from the ECU. The ECU was designed to run like this so I was hoping it will work. But on another note is this an unreliable way of running? Should I be looking to convert to EDIS module instead. Im looking for a degree of reliability doing this.

Thanks