d1998a dfi module or v6 rodeo module

[antus]

Yeah that has been done before and should work. Any kind of reluctor should work.

[SoullessShadow]

Ok so I tested the standard jackaroo CAS and it was 0.997k ohms so 1k the vt abs I got was 1.6k and a random van one was 1.08k so hopefully if I can fit them one of those will work and it's not super fusy on amplitude. All the smaller sensors in the jap and euro stuff measure at 4.5 to 6M ohm

[SoullessShadow]

Messed around trying to make the vt abs sensor work. Eventually got it reading an rpm. But it wasn't as stable as id like between 170 and 200rpm with drop outs to zero and then spikes up. That was with a 0.032" air gap. Closed it right down to 0.0015" had no more spikes but still some drop outs to 0rpm but mostly stable 180 ish rpm cranking with the plugs out.

I gave it a try like that and it fires and tries to run but as soon as it does fire it's like it loses the rpm signal but no back fires or anything like. I have no timing light or scope here. But I'm guessing the base timing is close enough just need a cleaner signal.

I'll try and rotate the sensor as the pickup is super wide compared to how wide the teeth are so I tried it with the narrow way first I'll spin it 90 degrees and see what happens

[SoullessShadow]

Seems the module is super fussy for something. Tried all sorts of air gaps etc and it keeps reading pretty stable and then drops out for a sec then back again just cranking with the plugs out. The bigger the air gap seems to slightly increase the rpm it thinks it's seeing until you go up to 0.030" then it starts to get big spikes.

I've ground the teeth for the cambelt down near where the trigger is but didn't help anything at all stated the same.

[antus]

Yeah it is a difficult system to get right. It is super sensitive about tolerances. Not sure where you are reading the signal from but if its distributor there might be enough movement there to cause issues too. The resistance doesn't matter because its generating a voltage in a coil as the pins go past. There is no actual resistor or semiconductor in it and you'll be getting a voltage from any of them.

[SoullessShadow]

Reading direct off the crank. But at a much smaller diameter and the plate/blade is ~1.5mm thick so that could be a lot of the problem too.

Another thought I had was to use the engines factory hall sensors and have the crank blade with 18 teeth which is a pain as id have to put 1 back on at least dues it being 36-2 std and then use the factory cam sensor as the 3x pickup but as it spins half crank speed would need to have double the teeth and work out how wide to represent the 10deg, 20deg and 30deg spacing. But that seems like even more stuffing around to suit a rule set that is stupid in the first place

[delcowizzid]

You have to have the abs sensor around yge right way to get full voltage if it's turned 90 degrees off voltage output is low.it also needs to be on s very solid bracket or any harmonics in the bracket ruinnthe signal quality.aldo shielded wire

[SoullessShadow]

I'm pretty sure I have it the way it's usually mounted now. With the wide pickup across the teeth. It didn't seem to make any difference though. It's bolted directly onto the block where the factory sensor goes so it's as solid as it can be for now. I have to grind the sensor down so can mount it and then epoxy it to the original sensor mount.

I think maybe the trigger plate is to thin for it to pickup well. I have room to maybe stack another one behind it to wat least double it.

[antus]

Volts rise with the speed the gap or tooth moves past the sensor. So the smaller the duration as it passes the sensor face the lower the output. So this is both a factor of the size of the trigger wheel and the rpm. Cranking speed will always be the lowest voltage you see and need to trigger from. Hall wont have the same problems as the signal is amplified to a nice clean square wave always, but also does not suit this module.

[SoullessShadow]

Yeah that's what I'm thinking could be a problem. From looking at the wiring a commodore CAS is a hall effect sensor so if I was to go that way I could use the std hall sensors on the crank and cam and just wire it accordingly?

I will try and get the jackaroo dis to work first though. I feel it's pretty close just needs some fine adjustments. It has the shielded factory wiring all the way past the injectors and plug leads then the last 200mm to the sensor is just the abs sensor wiring. But there is nothing electrical near it so I thought it would be fine to do that but maybe it's getting noise from somewhere. It's all a guess until I get a scope and see what it looks like.