I am getting tach spikes and drop out on my megasquirt install and am lookign to find out what crank sensor you used and how was it wired ?
I replaced the 12 tooth wheel with a 36 -1 wheel and the oem sensor
now either my sensor is bad or I got it wired wrong or the wiring is the problem so I am looking to find out what sensors you used or what other cars crank sensor is a drop in fit on the 1uzfe ?
What exactly is it doing? Does it totaly loose sync above 3000rpm? I'm assuming your NOT using EDIS. Have you set the VR pots to fully counter clockwise?
If so you may need to change some components in the VR circuit in the megasquirt. I don't have my 1uz running yet but I did have a ford falcon with a 36-1 wheel and It wouldn't rev above 1500rpm untill I changed some components.
Try changing C32 to 0.001uf and c31 to 0.01uf. That fixed my ford. There are a lot of threads covering VR problems on msextra.com.
ok at idle the timing "seems" spot on and follows the map or if i use fixed advance it follows that on the crank pulley
if I blip it lightly it follows and stays true to the map
if i blip it harder to go above 3k rpm or on the road at 3k rpm it all farts and bangs
if i watch the crank pulley on a timing light when doing this the timing retards until it goes negative at 3k rpm - depsite the map calling for more advance
from idle to say 2500 rpm its a peach - from 2500 it goes backwards (as the timing is retarded) until 3 k rpm is reached
the reason I say seems is this is what the timing light tells me - but I have a simple inductive timing light
and the msd claims to make a spark duration of 20deg crank rotation - could that be screwing things around ?
the 'squirt is driving a MSD dis 4 and I have 4 double ended coils in wasted spark
the trigger wheel is a custom 36 - 1 patterned off the oem 12 tooth
she starts first turn of the key and will idle all day long as smooth as can be - but dont rev to 3k rpm
my thoughts are
1) vr sensor is faulty hence why I am looking for another to substitute
2) my custom wheel isnt giving a clear trace
3) my wiring may be dodge - but i doubt that
4) is the msd giving me grief ?
I have been told a HALL sensor is the way to go to reduce half the grief hence why I am looking for one that I can drop into the existing oem location - fitting that would overcome all other questions
I don't think the MSD would be the problem. Are you running MS1 or MS2extra. If your running MS2extra then in the bottom right corner of megatune there will be an indicator that says synced. It should be green with the engine running. Watch that indicator and rev the engine over 3000 and see if it goes red. If it goes red the it means you have a problem on the VR input side of the MS. If it stays green then you probably have a wrong setting somewhere.
I borrowed an oscilloscope from a very clued up friend (he came free to help drive the scope)
the signal at idle was crystal clear however as soon as the revs increased the singal ot weaker and weaker and the ecu would then by default retard the timing
we tried shaving the oem VR sensor to get it closer - we rebent the trigger wheel to get it absolutely central over the sensor - we ran new shielded cabling direct to the ecu
still no joy
but the good news is !
I grabbed the oem trigger wheel - ground off the tooth directly opposite the keyway marker
fitted that to the motor
grabbed another stock sensor - fitted that
and still the same problem !
(Daniel Devoigt=devojet) suggested a 10k resistor - Thanks Man !
VOILA
I fitted the 10k resistor on the signal wire of the oem sensor
I had to trim the timing 4 degrees
but I have a crystal clear RPM signal and can rev to redline - so after a few months of changing at 2800 rpm
I can now enjoy the other 4k rpm of power band !
now how do I get more boost from my supercharger - need more POWAH
megasquirt actually has a specific setting for the lexus twin dissy motor and a number of people have used it
sign up on the megasquirt forums msinfo.com i think and start reading there
its a damn awesome ecu i have to say
I plan to run with the duel dissy and factory Crank and cam sensors. I have the engine, Megasquirt, LCDash and GPIO board (to control the gearbox). I just need to finish building the Hot Rod around it so I can get it running. I have done 3 other non 1UZ Megasquirt installs so I'm very confindent that it will run the 1UZ.
To Run the duel Dissy's you will need to run the MS extra firmware. www.msextra.com
