Dual Knock Sensors

Post by **Coops** » Thu Aug 06, 2009 9:31 pm

not sure if any of the MS guys can help.
have mailed a few vems guys on the vems forum but had no reply.

im looking at running dual knock sensors and wonder if there is a certain way they will need wiring in?
i gather they dont both connect to the same pins on the ecu.

r2d2hp · Post by **r2d2hp** » Thu Aug 06, 2009 9:43 pm

I was going to run knock sensors Tony, even had the block drilled and tapped but Dave Walker advised that if the engine is mapped properly then they are not required.

So did not bother with them.

r2d2hp · Post by **r2d2hp** » Thu Aug 06, 2009 10:09 pm

Found this

http://www.vems.hu/wiki/index.php?page= ... FUserGuide

Bottom of the page Vems 3.3 pin outs - does that help

Post by **Coops** » Thu Aug 06, 2009 10:16 pm

im going to to be safe mate, as nitrous can be funny stuff

r2d2hp · Post by **r2d2hp** » Thu Aug 06, 2009 10:17 pm

Did that page help at all, if not will keep looking

Post by **Coops** » Thu Aug 06, 2009 10:30 pm

yes mate thats good ta,
thats the latest pin out which i dont have (do now)

also i have been told to earth the sensor shileding at the ecu end,
but there it says to the block,
so i need to look into this also now,

next bit comes trying to set the ignition side and knock side up on the ecu

dnb · Post by **dnb** » Thu Aug 06, 2009 10:34 pm

Run a decent shielded cable back to the ECU and earth it there. Earthing knock sensors to the block is not the way to go.

I haven't looked at your ECU config yet, but I will do so before the end of the weekend.

Post by **Coops** » Thu Aug 06, 2009 10:51 pm

cheers Dave,
im wiring the extra wiring to the ecu plugs (ec18 and ec36) this weekend for the knocks and crank trigger,

Post by **Coops** » Thu Aug 06, 2009 11:10 pm

Dave have you the old layout with the tach output listed?
as i cant find any reference on the posted page on the vems site on wiring in a stock tach to the vems,

i did have it writen down but cant find it,

edit:
ah i see channel 4 (pin3)
is a common one to use on the p259 chip.
will i need a pull up to run my rev counter? (stock rover sd1 counter)
and whats the divide for in the mt settings?
sorry i know its not knock related but its along the same lines lol.

dnb · Post by **dnb** » Fri Aug 07, 2009 11:19 pm

Your tacho might not work with VEMS (or any other ECU) without a converter box. IIRC the SD1 tacho took its signal from the coil -ve, so is expecting 400+ volts of signal. VEMS will provide +12 with a pullup which may not work without the converter.

It's OK to use the P259. I use a channel for tacho driving on mine.

The divider was 8 for my tacho, but it died shortly afterwards (no damping in the coil) so I took it out to fix. Needless to say I didn't finish!

Post by **Coops** » Sat Aug 08, 2009 8:34 am

oh bugger so no rev counter then

what about the autometer rev counter i have?
will that need a converter box to?
starting to wish i left the dizzy in now

dnb · Post by **dnb** » Sat Aug 08, 2009 9:41 pm

The autometer tacho should work.

Post by **Coops** » Sat Aug 08, 2009 11:28 pm

without any add ons?
straight off the ecu?

topcatcustom · Post by **topcatcustom** » Sun Aug 09, 2009 9:39 am

Tony I had an autometer (I think it was anyway) tacho in my mini and it just took a signal from the coil, plus a power and earth, easy. It also had a switch on the back for 4/6/8 cylinder engines, wasn't an expensive gauge but it did the job fine!

Post by **Coops** » Sun Aug 09, 2009 9:46 am

i know how they wire up mate,
but dont forget im not using a dizzy now,
its crank trigger and coil packs so the ecu needs to trigger the rev counter now.