megajolt problems!
Turbo Mini Forums

hey up all,
i'm having a some problems with the tachometer and the megajolt. basicaly i went to wire up the rev counter today, its just a cheapy tim one in a pod. i tried going via the output on the edis unit, but no joy, and it only seems to get a very low voltage out of it .64v i think? then tried the one from the megajolt and there was nothing atall? followed up on that and then found the switchable outputs dont work on the RPM setting (i tried setting it to switch on at 2500 rpm on each one and got nothing), but they do on the MAP ones, and in the runtime display its not giving me an RPM readout (although im not totaly sure it should even do it?) is it me not wiring something up right, between the jolt and the edis unit or is it something under the surface?
it seems to run alright other than this odd problem!?
any help would be much apreciated as im sorta stumped now.
oh ive got 2 wires going between the edis and the jolt, saw and pip i think? that right or am i missing something?
cheers
steve

doh! why did i start messing with it!

I haven't done this yet, but if you are knocking up tacho drivers Pete I would also be interested in one.

i connected my tacho up to me EDIS module and it works fine. i must be lucky. so id try yours first tom.

no longer a series, but still 1.3 turbo.

oh that'd be great pete! anyone got any ideas on the problems with the switchable outputs?

doh! why did i start messing with it!

yes please pete :)

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Many tachometers can accept the 12V signal emitted from the MJLJ module. however, some OEM tachs detect the RPM signal by sensing the high voltage flyback pulse from the ignition coil. In distributor based setups, there is only one ignition coil to detect this pulse from. With a wasted spark system like the Ford EDIS, you will have multiple coils providing this signal. Consequently you may need a way to detect this pulse across multiple coil-packs.

The following circuit allows the flyback pulse to be detected across individual coil packs while still isolating the coils from each other:



Alex

AlexF

24/01/2006 18:44:06 PM User | Quote | Edit
you can do what wil_h done use the output from the EDIS

first did you use 2x 1N4004 diodes and 1x 1N5352B zener diodes


the two 1N4004 diodes on the coil pack
then the zener diode be for the rev counter white/black wire

all diodes are direction so the current flows one way so make sure they are the right way round

good luck



--------------------------------------------------------------------------------
whats next to blow up under the bonnet !

Edited by jimmy on 1st May, 2006.

1293 Turbo mini

The ford edis coil is two coils in one coil pack so you need the diodes

1293 Turbo mini

lol i'll defo have one please peter, i can just about manage to get a little solder on a wire or two and give myself 3rd degree burns but thats about my limit with a soldering iron!
cheers for the info
steve

Edited by hippyinamini on 2nd May, 2006.

doh! why did i start messing with it!

peter can i be put down too, ive the feeling ill end up with a bold patch on my head from head scratching

On the same subject,I have a tacho off a 4 stroke single cylinder motorbike-Has 3 wire pos/neg and green pulse.

How would that work

Metro turbo weekend driver,Mini turbo in the making again!

I think it will not work because it is a single trigger per cycle were the mini is four per cycle

1293 Turbo mini

Hi,
One for me too, please!
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

AlexF

Please can i buy one too

Previous Engine: 1040cc Morespeed engine, 1275 turbo head T2 Turbo Mirage Manifolds Megajolt
Previous engine: STD metro turbo, megajolt
Drives: 399bananahp (flywheel) Honda Civic Vtec b18c4 T28 Turbo 1968 Mini

Megajolt maps to download: http://www.jamesfawcett.co.uk/cms/index.ph...&gid=3&Itemid=3

me too:)

the Y lead would be good, for me at least!

Yes, Y lead fine for me also.

nice one!

lol sounds good to me!

doh! why did i start messing with it!

Hi,
Keep us informed, tested products are always best!
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

argh my heads hurting now, right update... turns out the megajolt aint working atall, it links up to the computer ok but isn't actualy working the engine. i finaly found my old timing light and tested it to see if it advanced and not a sausage, tried testing if it altered when the information was changed and nowt, finaly took it off and ran on edis and it was the same so its been running on default all this time, the thing that threw me was its a few deg more advanced than it should be, hence it running well enough to drive and going like a scalded cat on turbo but bogging down off it.
ive also descovered that its a v3 board not a v2 which i was told it was. so ive wired up the molex plug a la v2, so the tps pins have 12v to them, would this by any chance be causing it to bypass the map sensor looking for the tps signal? its a bit late to start trying things tonight now :(
and what should the pip and saw wires be giving out voltage wise because theres either some info not making it to the jolt telling it the rpm, or theres a problem in the jolt... but as such im not sure how the pip and saw wires work in relation to the jolt.. so i dont know what to look for
ive asked on the megajolt site too but replies seem to take some time on there

steve

doh! why did i start messing with it!

Steve

I did this by mistake (wiring the plug wrong).

Have a search on the site, I posted the correct V3 pinout on here somewhere, use can use as a reference.

Also have a search on the net, there is a good explanation somewhere of how the EDIS uses the SAW and PIP lines. Try the Bowling and Gippo (or something like that LOL) MegaJolt site.

http://www.bgsoflex.com/mjl/mjl_edis_summary.html

Have a read of that. Although it goes a bit deep, the main thing to note is that the PIP and SAW lines should not have a "voltage" they are used to carry a signal, and so unless you have a decent oscilloscope it is hard to test the signals on those wires, you just have to trust them as being true.