toyota 20v oe trigger

[Denmark]

Hi All,

Did any of you get the vems to read the 20v oe trigger from the cam, 24tooth wheel,
without removing any teeth from the wheel?

Or do you all go 36-1?


/Skassa

[rob@vems.co.uk]

Skassa!  How you doing?

I have had the 24+1 (late), and the 24+4 (early) triggers working on the test bench, but the trouble comes when I tried the 24+4 in the car - the harness injected so much noise that the trigger would fire like mad, creating ignition sparks when the engine wasnt running!

We cured the noise with a 272Ohm pull down resistor, but alas, this did not clean up the trigger signal enough to get a sensible reading.

IrishTwinCam (Peter) and I have been looking more at how to approach this, and with Jorgen and Emil's help we have a strategy that we're going to try.

For the moment though the Raw Engineering 36-1 kit is the best option for the 20v conversions because it doesnt threaten the bulkhead, although if you're keen to try the ideas Jorgen and Emil put forward I'll be keen to see what the result is, Peter doesnt come back from Holiday for a few more days.

[Denmark]

Hi Again,

That´s the noise i talked about , when i first installed the VEMS,i had it down to some strange misfire ,when the engine is cranking, but none when the engine is running,

But i have removed 2 teeth from the 24thooth wheel, so not using more then one of the 3 sensors, that are there,

Right now i have the engine out of the car to get it bored,and some low comp. pistons put,Then i´m going to boost through the itb´s, that will be fun to see if that can be made ,so it´s going to be bearebly.

/Skassa

[rob@vems.co.uk]

We've got a couple of air fuel metering strategies that are designed to work with Boosted ITBs.  The MAP multiplication uses the same algorithm that was used on the Ferrari F40.

[Denmark]

We've got a couple of air fuel metering strategies that are designed to work with Boosted ITBs.  The MAP multiplication uses the same algorithm that was used on the Ferrari F40.

Yes, I look forward to try and map a car with tps/rpm, as i have newer tryed that, but hope i will get to lean that,

/skassa

[Denmark]

Rob, do you have access to a Oe toyota ECU, then i could be possible to look at the trigger input on that , to see how they remove the noise!

/Skassa

[rob@vems.co.uk]

It would be nice to see how its done, currently we have a few more options to try.
First as the 10K pull-ups seemed to clean the signal a little, Peter (IrishTwinCam) has been researching and found that the sensor's ground signal is rasied above zero.  So we're going to try to use smaller pull-ups in order to replicate this voltage rise.

If that fails we're going to go back to 272Ohm pull-down resistors and I'll solder a jumper that sets the zero point at 200-450mV.

And if that fails we're going to use an independent ground direct to the LM1815 sensor chips, which can be pulled up to the same voltage as Toyota use.

And if all that fails then its a Raw Engineering front pulley and coil pack (which is soooooo much better than a distributor that I dont know why we're trying to use it!)

[Denmark]

Okay,

So you are saying dont use the distrubitor

Maybe i have to use that 36-1 wheel, i just think it looks cleaner eith the oe trigger


/Skassa

[rob@vems.co.uk]

I'm suggesting that we're going to give it our best shot, but bear in mind that there is another (better) option

[irishtwincam]

It should be noted I have a chest infection as a result of testing this stuff
Standing in the cold in a tshirt waiting for an rpm signal.
*cough cough*

But I am determined to see this solved!

[Denmark]

 


I have been driven my blacktop engine using the oe trigger last summer, so it is working, just not perfect,
I have this strange misfire when cranking, but as soon as the car starts, it runs perfect.
but that is when i have remowed two teeth from the 24tooth whell, and only running of the ne signal.

/Skassa

[rob@vems.co.uk]

Thats the thing, removing teeth might look to you and me very obvious, but to the VR circuitry it might look very different.
Also IrishTwinCam and I have found that the G1 line was so noisy that it was causing the VEMS to trigger left right and centre and kick out sparks like mad.  When I test Toyota 24+4 and 24+1 distributors on my pillar drill they work perfectly - so its either noise caused at low RPM (cranking) or because the factory loom is a hell of a noisy thing.

We've got some things to try (more pull-up voltage, and pull-downs with some capacitors to filter noise) if they dont work we'll have to get the scope on it and start designing circuits

Rob