Any megasquirt gods can you help.....

[GreenV8S]

neal1980 said:

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.

I had all sorts of problems getting my OMEX to run like this, but the MS1/Extra system has fired up straight away with no reset issues. It's very obvious in MegaTune when the reset problem occurs, and there's a well known workaround to add capacitors to the circuit if you run into that trouble. But I haven't had any trouble, running (as far as I can see) the identical setup.

To start with I suggest you test the LT side to make sure you understand what's going on there. The behaviour you had before sounds very wrong so you need to resolve that before you have any hope. Hopefully just a duff meter though. Once the LT side has been checked out you can just stick a test lamp across where the coil should go, crank the engine and confirm that the ECU is driving the coil correctly.

[eliot]

The other thing that springs to mind, is that you can burn the drivers out very easily if you dont follow the instructions to the letter, i.e. the spark inverted setting, dwel and disconnecting the coils whilst doing the initial setup and flash burning it. I would assume Phil R. would get those basics done for you, after applying the mods.
Have you had a peak inside? - do they look ok (not cracked, red hot or smell of burning)

Typically the 12v for the coils is via the fuel relay, so they dont get 12v when the engine is stationary.

Edited by eliot on Tuesday 22 January 08:00

[ihatesissycars]

You can get coil test lights which you insert into the coil multi plug and it will blink whilst cranking if the ecu is working. Mine did though and still wouldn't trigger the coil!

You could (if you're feeling lucky try and ground a coil and see if you get a spark, again mine did but it still wouldn't work!

I say Edis all the way, it works so well and has that 10 degrees back up should the ign side of the ecu fail and it always just seems to work.

[neal1980]

Well I will be trying tonight all manner of things.. Cheers for the idears guys so far. Just need to pack the Bird off to tescos for the night.

I think I may of found a fault looking at the wiring, I will check tonight and see. I will post back the results....

Fingers crossed here!

I will still be looking in to EDIS though sounds bit more reliable :-)

[rev-erend]

Is it possible your coil packs are not working..

[neal1980]

Ok well after all of that it was err me! I had not put the coil pack power on a proper switched ingnition feed. Changed this and it fired first time.

Was unable to run the car for long as neighbours but seemed to be very rich, and when it came off warmup the revs shot to 3000 rpm. Will have to have a play tomorrow night but at least it running now :-)

If my ignition settings are incorrect could this cause the high idle?

The base map on the ECU was for a 4.6 and mines 4.0, i just wasnt expecting it to hover at 3000rpm. Should there be any checks first or shall I just start messing and see what happens..

Thanks for the all the replys tho guys.

[GreenV8S]

Well done, isn't it a great feeling when it finally fires up?

Fast idle indicates that too much air is being allowed in with the throttle closed. Either an accidental air leak, throttle plate not closing fully (throttle stop / pedal / cable / etc) or if you have an idle control air valve that may be messing up and going fully open. All the ECU can do is control the fuel and spark, and without extra air flow neither of these on their own would cause the idle problem.

[eliot]

Which plenum top do you have? the old hotwire one or a gems one?
Either way try blocking the idle stepper passage.

[rev-erend]

Congratulations..

Clamp the pipe to the EAV (Spepper motor) with some mole grips .. I'm sure this will show where the problem is..

Edited by rev-erend on Thursday 24th January 12:21

[neal1980]

Hi,

Yes it was a great feeling when it fired, makes all those evenings with the soldering iron worth while now. Im not running any air valve at the moment, and I have disconncted the stepper. I will try clamping pipe in the next hour and see what happens. Its a hotwire plenum in a TVR Chimaera.

Thanks

[neal1980]

Correct again guys! When I clamped the hose normal idle. I have now cut the hose and blocked both ends as im not going to be using an idle valve yet.

Now I need to learn how to map the thing!..

Thanks again for your help peeps

[GreenV8S]

By the way, I don't have an IACV and have no plans to fit one. I have set a sharp step on the ignition map to stop it dropping below my target idle speed and then set the base idle so that it is just barely 'touching' that step when it's up to temperature. By happy coincidence this also means that it's running very retarded at hot idle which I'm hoping will help with the emissions test. Probably not ideal for sitting in hot traffic jams, but that's sorted by having a proper cooling system.

Edited by GreenV8S on Thursday 24th January 20:24

[mtechmatt]

Hi all,

Just looking over those top trigger angles, and I notice you have a return on tooth 38... there are only 36 teeth (techincally 35) on the trigger. This could cause the VB921 to stay on for a full cycle, which could damage it.

IS it running A-Ok, with no over heating?

Matt

[GreenV8S]

mtechmatt said:

Hi all,

Just looking over those top trigger angles, and I notice you have a return on tooth 38... there are only 36 teeth (techincally 35) on the trigger. This could cause the VB921 to stay on for a full cycle, which could damage it.

IS it running A-Ok, with no over heating?

Matt

Yes I agree it does look funny, and '38' should probably be '2' or something.

However, I've left it like that because:

• The figures were provided by Phil using the trigger wheel calculator.
• It starts and runs fine.
• The case stays cold.

I have assumed that somewhere between MegaTune and the firmware the tooth counts here are 'modded' to be less than the total number of teeth.

BTW in those figures '32' should be '33'.

[neal1980]

Ive just checked my case and its cold ive had it running for about 6 hours total now and it seems fine.

Adjusted the idle today with the VE numbers and its not so rich anymore, got it to 14.4 at ldle and it sure seems good. Cant wait till feb 1st when I can tax it and go tune.

If anyones got any maps to share for the V8 4.0 I would be intersted to see them.

[neal1980]

Ok ive been reading up on tuning and my map appears to be very rich indeed on tickover and when I rev it up I get bits of fuel black smoke out the back. When I played with a few fuel numbers around tickover I managed to lean it out to 14.7 and it seemed much happier.

Do you think I am better to put the original values back in then re-scale the whole fuel table down maybe 10%? or just work around the table slowly on a drive out. And if I adjust the required fuel does this make the fuel table a bit leaner?

This is gonna be a big learning curve but it seems fun. Hopefully no melted engines :-P

[GreenV8S]

If it's *very* rich you might run into trouble with plug fouling before you get a chance to map it. In that case you might want to lean it out a bit everywhere so that it is only slightly rich, then do your logging and analysis runs. You can lean it out by scaling the whole map or by changing req_fuel. I think the standing advice for req_fuel is to set it so your VE values are in the right sort of range so you have plenty of resolution (VE values not too small) but no danger of running out of range (VE values too high).

[Eales V8]

Not using EDIS is a harder route.
Re tunning ensure your map is sound - if you wnat to shove up a JPeg of it I'll have a lookie, but need to know spec ie cam BVH etc. Re Fuelling best thing you can do if you haven't already is load MegaLogViewer and the java software to make it run from the MS Site.

Then plug in a PC and dtat log via megatune, then run through MLV as a starting point

If you go to www.lr4x4.com tools and fab forum there is a long thread I have posted and others have contributed to on Rover V8s and Megasquirt, may well be a load there that may be of interest

HTH

Nige