MS2 - No rpm (v3.0 board, running EDIS) - Now working

Quagmire · Post by **Quagmire** » Sun Jul 27, 2014 11:29 am

I have posted this on the MSextra forums, but thought I might as well put it on here as we get a bit more traffic, and you lot are pretty erudite and might have some suggestions!

For now as I need the car for work I have removed the MS and reconnected the MJ, which is running perfectly - i.e it has an RPM signal.

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So I have finally got around to getting my freshly built MS2 in the car - but I have no RPM. The car runs, as It was on Megajolt before and still has the SU's, so I know the EDIS wiring is sound.

The ECU works, as I flashed it with 3.3.2 ok. I can connect it to the PC and tweaking the pots on the stim (Megastim 2.21) shows changes in IAT, CLT, TPS etc. I can read from it and burn changes to it as normal too. I get no RPM on the stim, but never did on my previous MS1 builds. Should I see an rpm on the stim now that I am using the VR circuit to as input?

I followed the manual, and made the mainboard changes as per section 5.2.4, and 6.7.2, including the twiddling of the pots anticlockwise 12 turns and the bottom one 6 turns back.

I have setup the software side of things as per the manual as well (hopefully) - see attached msq.

I have the PIP and SAW connections on pins 24 and 36 of the DB37, and have done a continuity test to confirm.

I have tried swapping the PIP and SAW wires over to the MS, no change.

Can anyone suggest anything I have missed? Photos of board attached, and MSQ.

Also worth mentioning the following two facts that may be related:

On assembly I noticed that D18 was slightly chipped at the end out of the bag,

and

I noticed just now that the TPS gauge continually climbs very slowly when on the car, even though it is not connected to anything at present. This may be normal though as it behaves on the stim ok.

Many thanks

Jamie

SimpleSimon · Post by **SimpleSimon** » Sun Jul 27, 2014 6:49 pm

If the MS is receiving a signal from the EDIS8 PIP output then it should show an RPM reading while cranking in Tunerstudio or whatever software your using

Quagmire · Post by **Quagmire** » Sun Jul 27, 2014 8:17 pm

You would have thought so wouldn't you?

I know for a fact that EDIS is working because the car starts and runs, works fine and advances etc when checked with a light with Megajolt. It has been using MJ for a few months now, no issues at all.

On the MS DB37 I have the PIP coming in on pin 24, and the SAW is on pin 36 (I just buzzed them out again with the multimeter to triple check).

I even tried swapping them over on the car just incase I had got them backward somehow, but no effect there.

Argh!

DaveEFI · Post by **DaveEFI** » Mon Jul 28, 2014 8:36 am

First thing to do IMHO is get it working correctly on the stim, on the bench. The Stim produces a very similar tach signal to EDIS so if it works with one it will (should) work with the other.

Quagmire · Post by **Quagmire** » Mon Jul 28, 2014 11:48 am

I have come to the same conclusion and yesterday removed the MS and reinstated the MJ in control of the ignition. This is how it will stay until I get something to happen on the bench!

Spent some more time last night trying to slowly and systematically adjust the pots in the hopes of getting something, but nothing, not a sausage!

My next plan of attack is to see if I can spend some time tonight checking components with the multimeter to make sure I have no dead parts. Will update if I find anything.

DaveEFI · Post by **DaveEFI** » Mon Jul 28, 2014 1:16 pm

I'd start by checking the stim since you say you've not been able to get that to work. It will happily fire an LED with a 1000 ohm series resistance. If you set the RPM to slow, you should see it flash and as you change the revs to higher it will appear to be on permanently.

That's assuming you don't have a 'scope.

With all this sort of fault finding, you need to be sure each part is working correctly. Guessing is a recipe for frustration and throwing money away on new bits.

And the idea of a stim is to check out the MS is working (the basics) before fitting it to the car. And it will provide a test signal similar to EDIS - it's with a VR signal where things become more complicated.

Alternately, I'd be happy to check out the stim (and or MS) for free. Just charge for any repairs if needed.

Quagmire · Post by **Quagmire** » Mon Jul 28, 2014 8:16 pm

Thanks Dave - I will check the Stim and go from there, I don't have the money to go swapping bits at random!

Your offer to check it out for me is very much appreciated, a true gent! I won't take you up just yet if that's ok, I will keep chipping away a while longer, its the best way to learn how things work! If I do get to a stage where I feel I am getting nowhere I will PM you if that's ok.

Many thanks again,

Jamie

daxtojeiro · Post by **daxtojeiro** » Mon Jul 28, 2014 8:51 pm

Im confused! You havent followed the wiring for an EDIS setup as it been built for a VR input, yet no VR transistors.
That will never work the way its been built.
Dont blame the MS, its not been built correctly,
thanks
Phil

DaveEFI · Post by **DaveEFI** » Mon Jul 28, 2014 10:56 pm

Well spotted, Phil.

Quagmire · Post by **Quagmire** » Tue Jul 29, 2014 7:21 am

Phil,

Sorry for the confusion - if you are talking about Q22 and Q23, they were fitted after I took that picture (I thought I was finished at that point, and only noticed I hadn't fitted them when I was tidying up my work space. The same applies for R40, I had put it aside with R39, fitted R39 later and then forgot R40!)

I should have taken newer photos

Please don't take this thread as any kind of criticism of the MS - the only thing at fault here is me, and I am just after a few pointers to get me on my way.

Can you see anything else that may have been missed? I think I have everything jumpered correctly.

Thanks again

Jamie

DaveEFI · Post by **DaveEFI** » Tue Jul 29, 2014 8:29 am

If it's been assembled from a kit, even more important to get the stim working so it can be tested properly. There are lots of possibilities as to why it's not getting sync, so best to make sure the VR input is working correctly first.

One fairly common problem with a DIY build is solder bridges at one of the small transistors, as the pads are very close together. So I'd check Q22&23 carefully with a magnifying glass under a strong light.

Quagmire · Post by **Quagmire** » Tue Jul 29, 2014 9:00 pm

It is working!

I tried the LED on the stim, it was pulsing but doesn't seem to go off, rather it stays dimly lit the whole time, and pulses more brightly. I had a 1k resistor in series with it from pin 24. Twisting the RPM knob makes it speed up or slow down, so it is working on some level but not 100% correctly I don't think.

I then turned my attention back to the MS board. I removed the daughter card and then had a look at all the small transistors. None seemed to be bridged, but I ran a scalpel blade between them anyway. The PCB was looking a bit "sweaty" too, I think there was still residue left from where I had cleaned the flux off. I had another go and rinsed with water, before carefully and slowly drying it out with my wife's hairdryer.

Lo and behold, nothing on the stim still, but as it's only a matter of swapping a few wires over I decided to try it in the car anyway. It only flipping well shows RPM now!

So now it seems like my Stim RPM output is questionable, and I may have had a bridged connection somewhere causing me grief on the MS.

I have just got back from a 20 mile toodle around the country lanes of Hook and Basingstoke, with msDroid running on my phone keeping an eye on things.

It ran flawlessly.

Thank you everyone for all the support - especially Dave! I will see if I can investigate what's going on with the Stim a bit more.

Cheers!

Jamie

daxtojeiro · Post by **daxtojeiro** » Fri Aug 01, 2014 6:04 am

Jamie,
it may work but its not wired correctly for an EDIS setup, so it will probably have the odd miss trigger and wont be reliable.
Bascially youve wired it for a VR input, not a Hall inpput. The EDIS module gives out a 12V ground switching output, youve wired it for a VR input. The MS should be wired to accept a ground switching input, so it holds the input wire up to 12V and then the EDIS switches it to ground and the MS see's that as its trigger.
thanks
Phil

DaveEFI · Post by **DaveEFI** » Fri Aug 01, 2014 8:45 am

You've got me confused, Phil. Nothing new there.

I'm still using the opto input for EDIS on my car as it works fine, but realise it's now the norm to use the VR input. These are the instructions for connecting things for EDIS using the VR input from the Extra site:-

V3.0 board - VR Input for logic input e.g. TFI, EDIS, GMDIS, LS1/24X, modules
a) Solder a link between VRIN and TACHSELECT
b) Solder a wire between VrOUT and TSEL
c) With a small screwdriver, turn the pots, R52 and R56, about 12 turns anticlockwise (sometimes you may feel a "click" when the end position is reached, they can't be damaged by turning too far.)
d) Turn R56 back about 6 turns clockwise.

So is wired exactly the same as for a VR sensor. The only difference being the setting for R56?

volospian · Post by **volospian** » Fri Aug 01, 2014 9:12 pm

Those are the same settings I had to use for my L33 (24x wheel).

Not adding anything to this conversation, just saying

Rich.