It's Dead - Autopsy 080308
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Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Well I'm out of thoughts for tonight then... but your earlier photo of the partially melted fuse still says (to me) more than the 7amps the VB921 is supposedly internally limited to.

Good luck...

Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi,
I'm with you on that one Paul, they look like easymelt fuses!
Check for voltdrop across the fuseholder while cranking it over?
EDIT: Ammeter in circuit, check current draw?
Cheers,
Gavin :)

Edited by Bat on 24th Feb, 2008.

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Schrödinger's cat - so which one am I ???

I've been out there in the cold for several hours yet again.

I've checked everything in the minutest detail, tried various ECU settings that were working fine, checked the fuse holder, checked the MS board and the VB921s, checked the coil outputs.

There is some compression on all cylinders. Only measured by thumb over plug hole, but each cylinder seems the same.

There is fuel in the cylinders and I have a spark, but it will not run.

Even with two batteries the voltage on cranking is down to 10-10.5 volts.

I've bought a couple of coil packs off ebay to try next weekend. In the meantime, can anyone answer this question?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes it could be fucked,

there are 2 sets of windings, the primarys (12v) and the secondarys (HT)

In my experience when the coil packs fail its due to overheating, last time i had one go the resin had expanded and broken the tiny wires on the HT winding.

As a check each of the HT windings should be about 13K ohm, (i just checked mine, they are 12.6K)

As per Joe,
The two I have both measure about 0.8 ohm on the primaries and about 12.8 K ohms on the secondaries.

BUT, a DC resistance reading doesn't tell everything, there can be internal faults like shorted turns that still give a good DC reading but simply won't allow it to work as it should under the "AC" it actually works on.

However, you say you get a spark and 10V is perfectly adequate for the ECU to run (it only needs 5V, so say 6V (external) after losses from the 12 - 5V voltage regulator inside) so why is your spark suddenly not doing what it should ???

The most obvious question is did you make any other changes (no matter how small you might think them to be) between it running and suddenly not... It's often the silly simple changes that make the difference.

Sorry, that's not meant to sound patronising but sometimes it's the obvious that gets overlooked.

Rod.

Schrödinger's cat - so which one am I ???

Is the HT resistance measured between the posts ie 2 to 3?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Schrödinger's cat - so which one am I ???

They are both 12.6 - 12.7 KOhms.

Bugger.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

The other thing to check is that there is no connection (ie, it should be infinity ohms) between any of the four HT posts and the metal backplate OR between any of the three input tags and the metal backplate.

Again, internal faults could be a coil to ground fault.

There is no coil to ground wiring on a coilpack, unlike a conventional coil where there is...

Schrödinger's cat - so which one am I ???

Infinity between the posts and the backplate.

If the coils not at fault, I'm lost.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

can you slap a dizzy in it easily?

I think the coil is a non starter ( if you pardon the pun!) - I did all this messing with a second coil and comparing sparks - in the end it was a timing issue! A coil pack will not go down on both circuits simultaneously - if it had failed it would try and run on two cylinders.

The voltage issue is a concern - when I try and crank my engine on DTA when the volts are low and the lappy is connected the screen flashes a red message when the voltage is about 11V. Have you tried wiring the starter so it uses one battery and ECU/car has its own supply? Failing that try checking the timing when cranking using a strobe and check the figures against what the ECU reckons is happening.
Is it fouling the plugs?
Backfiring?
At all?

On 5th Sep, 2011 Vegard said:
I stand corrected. You should know

The volts have been coming up all day as it's charging, now cranking at about 10.5-11v with both batteries connected to the charger.

Timing light shows consistent spark at correct point. I've moved it five degrees each way as well.

Plugs are wet, but spark when pulled.

It occaisionally backfires.

I could fit a dizzy as a last resort. I'm more inclined to push it over a cliff.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

OK,

Do you have access to a scope ?

So far everthing seems to suggest the coilpack itself is still OK and the partialy melted fuses/holders are a red herring.

If it will occasionally backfire, logic says you have fuel and spark but not necessarily at the right time(s).

If you push it over a cliff, you may get the best 1/4 mile for a megasquirt port injected Mini (assuming the cliff is tall enough) but who would record it !!!

Personally I don't think the battery voltage is an issue, all the EMSs I've worked on will happily run at 6V (as the internals only require 5V) but their externals (ie, injectors) may be be a bit erratic so starting may be tempremental (but always happens).

So, back to my earlier question, was there any fundamental change between when it ran, and when it didn't ???

Given a scope I would look at a few of the actual MS outputs (not just what the laptop says).

Rod.

Schrödinger's cat - so which one am I ???

OK,

Do you have access to a scope ?

So far everthing seems to suggest the coilpack itself is still OK and the partialy melted fuses/holders are a red herring.

If it will occasionally backfire, logic says you have fuel and spark but not necessarily at the right time(s).

If you push it over a cliff, you may get the best 1/4 mile for a megasquirt port injected Mini (assuming the cliff is tall enough) but who would record it !!!

Personally I don't think the battery voltage is an issue, all the EMSs I've worked on will happily run at 6V (as the internals only require 5V) but their externals (ie, injectors) may be be a bit erratic so starting may be tempremental (but always happens).

So, back to my earlier question, was there any fundamental change between when it ran, and when it didn't ???

Given a scope I would look at a few of the actual MS outputs (not just what the laptop says).

Rod.

Schrödinger's cat - so which one am I ???

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

I think I have solved this little puzzle.

The clue is in the fact that the oil level has gone up.

In my haiste, I used some old injector connectors and just jointed the wires. The injector connector wires were a bit ropey with cracked insulation.

My guess is that the wires are earthing on the fuel rails and fuel is going in whenever there is pressure.

I'll try it in the morning, it's too late now. Wish me luck.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Hi,
There's nothing more frustrating than when you've got an "Everything does what it should but it doesn't work...." situation.
I've found just resting the plug leads on the ends of the plugs helps :)
Cheers,
Gavin :)

VEMs Authorised Installer / Re-seller. K head kits now available!

WB/EGT gauges. Click here for customers write-up

Visit www.doyouneedabrain.co.uk

My Mini build diary

jsut read this, good luck, hope you dont think i broke your car

turbo 16v k-series 11.9@118.9 :)

Denis O'Brien.

I think it was conicidence that the problem occurred at the same time as trying your trick.

The other possibility is that some crap has got into an injector jamming it open.

Don't injectors have integral filters?

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Yes they do have integral "basket" filters.