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Potentially stoopid question

Posted: Wed Jul 08, 2009 4:24 pm
by Midas
If I'd managed to damage a resistor (R11 for example :roll: ) on the limiter board whilst fitting it to the MJ, would that kill my coil power output?

Just asking like, 'cos that would be a really stupid thing to do...... :roll:

Rich
:wink:

Posted: Wed Jul 08, 2009 6:27 pm
by NITROPIXIE
Looking at the circuit diagram i believe it would, yes. Have you damaged the actual resistor or the track/pad its soldered too???

Posted: Wed Jul 08, 2009 6:39 pm
by Midas
It's the actual resistor that's physically broken thankfully, I was trimming a protruding solder spike with a blade and it slipped.

It's quite a relief that the resistor would stop play, I've fitted an immobiliser system at the same time as finishing the loom for the MJ box. Instead of cutting out the fuel pump (mine's mechanical) it interrupts the coil power from the MJ.

I've got 100 resistors on their way, it was cheaper doing that than it was to buy a single one and pay the postage.

Rich
:wink:

Posted: Wed Jul 08, 2009 6:45 pm
by NITROPIXIE
Don't think maplin sells them any more which is a pain. How did you order them from?? I normally go for RS components for mine.

Posted: Wed Jul 08, 2009 6:59 pm
by brentp
R11 is very important- it supplies the ground reference to the MOSFET gate on the hard rev limiter board. Without it the MOSFET will be damaged- not good! :)

Posted: Wed Jul 08, 2009 7:01 pm
by NITROPIXIE
Brent is it used for avalanche protection of the MOSFET??

Posted: Wed Jul 08, 2009 8:03 pm
by Midas
brentp wrote:R11 is very important- it supplies the ground reference to the MOSFET gate on the hard rev limiter board. Without it the MOSFET will be damaged- not good! :)
Oh arse!

I'll fit the new resistor when it arrives and if it's still not playing I suppose I'll be doing more shopping with you Brent.

Rich
:wink:

Ps. NitroPixie, these came off Ebay. I forgot all about RS.

Posted: Wed Jul 08, 2009 8:27 pm
by brentp
Rich,

if you're impatient you can solder a regular leaded resistor to the lads, just for testing purposes.

Ryan,

The ground is to prevent the MOSFET gate from floating when Q1 isn't conducting.

Posted: Wed Jul 08, 2009 8:44 pm
by Midas
I'm fairly confident that they will be here tomorrow, fitting the MJ is one of the last parts of a complete rebuild so there's still stuff to be doing while I wait. It would be nice to have it running though...

Rich
:wink:

Posted: Mon Jul 13, 2009 7:26 pm
by Midas
Oh well, that's what you get for being confident. The resistors arrived yesterday.

I couldn't get the engine to do anything other than fire occasionally on one cylinder, after going through the whole wiring loom I removed the hard rev limiter and hey presto! running Midas. :D That's the first time it's run on the MJLJ rather than just the EDIS side, everything seems to work fine, it's advancing through the map and I can switch the maps on the fly.

Looks like I blew the MOSFET, but I'll see how I go without the limiter for now, my days of revving into the red in every gear passed a few rebuilds ago.

Rich

Posted: Mon Jul 13, 2009 7:32 pm
by brentp
sorry to hear that, but glad you still have it running!

Send an email to [email protected] with your original order number and we'll see if we can sort you out.

Posted: Mon Jul 13, 2009 9:04 pm
by Midas
Hi Brent,

Many thanks, I've sent you an email.

Cheers

Rich
:wink: