Autronic SM4 vvti cam timing/position sensor - eccentric lobes?? a problem??

[ed]

im getting ready too making the engine go broom...

1uz vvti (intake cam) controlled by autronic sm4 ecu

the engine has a crank angle sensor, cam sync trigger, and two cam position/timing sensors on each intake cam

the problem is that the cam position sensor is trggered by a 3 spoke lobe on each intake cam,and these lobes are UNEQUAL

im told the autronic sm4 cannot handle this input to determin cam position for use with the vvti

is this correct?

anyone with direct experince with this issue have a work around?

software upgrade?

how can i get the autronic ecu to run the vvti with this cam sensor setup?

cheers
ed

[cambelt]

If all the lobes are unequal and if the autronic is happy with 1 pulse per cam revoloution then you could machine off the other 2 lobes.
This was common practice to reduce the no of poles on the reluctor inside dissys that had a 18 or 24 pole reluctor inside them when using aftermarket ecu,s that couldnt handle so many pulses .
Dave

[TheToyman75]

how can i get the autronic ecu to run the vvti with this cam sensor setup?

cheers
ed

Take it to a workshop/Dyno tuner who knows how to use it

Rod.

[ed]

rod - mos cant confirm

dave 'thinks' it should cope, but noone has tried yet, and mos hasnt even hooked his sensors up, let alone scoped them

[oldcorollas]

how unequal are they? lobe missing? or funny angles (in terms of crank angle)

[MWP]

I would take two lobes off and just use the one.
The ECU uses the crank for timing, so having a high resolution cam position sensor isnt needed.

[Draven]

ed: call Mark @ MRC tuners (castle hill) and ask him how he did mine.I know he was going to mke it trigger off 1, and as a last resort it was lobe trimming time - cabn't remember the outcome tho

[oldcorollas]

I would take two lobes off and just use the one.
The ECU uses the crank for timing, so having a high resolution cam position sensor isnt needed.

what if you want to run VVTI and need to know the cam position accurately?

[Celica RA45]

well i have 3 teeth on my inlet and exhaust and the reason, for cam position and for cam sync ,when to fire the coils for the inlet and what degress it is moving exhaust

no cam control you only need 1 tooth
other 2 are for cam movement to know where the bugger is

[MWP]

what if you want to run VVTI and need to know the cam position accurately?

Well then your up shit creek... can the Autronic monitor cam position for accurate VVTI use anyway?

Still cant work out why it would need 3 lobes to do that anyway.
On startup, use the cam pos sensor to find TDC, then after that use the cam pos sensor to monitor VVTI position. One lobe is all you need for that.

[oldcorollas]

i could be totally wrong... actually i think i am wrong (as usual)... if it has sync and ref elsewhere, then surely 1 tooth is ok, and the others are.. error checking? i dunno

[Celica RA45]

it needs the other 2 for advance and retard to know where it is

[Celica RA45]

you need a start and a finish for the cam movement ,how do you move the cam with only 1tooth which you need for ref any way
and the autronic should be able to do it as there was a 3sge beams with vvti that had autronic at the SAS dyno about a month ago
ask rod and speak to dave he should be able to help and ed dont be a tight arse ,if you had bought a motec m800 in the 1st place you would not have this problem now

[Draven]

it's not a amtter of the autronic not being able to do it, it's just how to make it do it. my 2j vvti has an autronic and fully functioning vvti

[TheToyman75]

Well then your up shit creek... can the Autronic monitor cam position for accurate VVTI use anyway?

Still cant work out why it would need 3 lobes to do that anyway.
On startup, use the cam pos sensor to find TDC, then after that use the cam pos sensor to monitor VVTI position. One lobe is all you need for that.

The Autronic can run and control VVTi - Of this there is no question. The question is not the autronic's ability, its the installation and the ability of the tuner.

A common event when building a car seems to be to spend your money on quality parts, dig deep for a high end ecu (Such as the Autronic or a Motec or late model Wolf) then choose to go tight arse and have it tuned by the lowest bidder. I think its a form of mental illness brought on by the overuse of a no name tool kit or repeated visits to Supercheap Auto. Personally since the tune is what makes or breaks the results from the built combination I choose to pay more for quality work and actually enjoy the benefits of my investment.

Please note I am not having a go at ANY tuner or workshop mentioned or infered. I am just stating what I see as a common trend day in day out. People are happy to spend $15 - $50 Grand building an engine over months or years with top quality parts. But then they cry about having to spend $6 or $700 dollars or so to tune it or having to leave it overnight.

ent Rant before I get carried away.

ED - The Autronic will run a VVTi Toyota if configured correctly, some of the VVTi toyotas have a trigger pattern that is still in Beta testing (yes we are doing some of this testing at SAS) I do not believe this to be the case with yours. Either way, Toyota put 3 lobes on it for a reason, don't remove them unless your confident your tuner actually knows what he is doing. As a general rule Toyota don't add bits or make them harder to manufacture just for the hell of making a vehicle less profitable to produce.