1zj ms3x syncloss issue

[md323]

have a ms3x built by diy
using the stock crank(mainboard) and cam(ms3x) sensors
all the grounds run to one lug on the intake manifold
both the crank and cam wiring is sheilded
sync loss
reason 17 and 11
and the MAT and CLT drops as I rev the motor


log and msq attatched

[quark2501]

its only 12 at crank. not 24 cam. same/same i know, but just to make it precise. I have my 1jz running now with out any problems. where have you connected the shield and ground for the vr?

[md323]

when I tried that it would not rev past 2500RPMS without sync loss, do you have an MSQ i can look at? maybe I got some of the 12 tooth settings wrong.

the VR sensors and shield grounds I cannot get to, the harness was rebuilt by a reputable local supra shop and is completely shrink wrapped I did confirm that the shield wires were indeed grounded.

[md323]

also her is an additional log of the issue. we tried a brand new crank angle sensor from toyota today, no change.

[quark2501]

If you Are using oem ignitor, then you need to lower dwell to make it rev. Iam sure you have a shield problem. I will post ms later.

[quark2501]

MSQ

[md323]

no dice

turning off the noise filter results in it not reving past 2500 so im 99% its the harness, now i just need to convince the owner of the car to tear it apart

[md323]

after getting everything else tripled check its still running like ass. the cam signal seems to be the issue from what I understand from the composite logs. any idea on how to fix this?

see attached graph

[jsmcortina]

Please post the actual logfile.

James

[md323]

done

[quark2501]

Which cam sensor are you using?

[md323]

The rear sensor

[md323]

ok so now we have tried a new cam sensor,
tested the wires for the cam sensor, not appreciable resistance.
the shielding is grounded.
car runs pretty on the factory ecu (yes I know this isnt a direct comparison but i wanted it noted)
tried adjusting the pots on the x card according to DIY's guide.
also tried all possible combos of ignition capture settings. (rising, rising is the only one to work)

any other suggestions?

[quark2501]

If I was you, I would look at the problem with the falling MAT as rpm goes up. Fix this first, maybe its related..... I would check for problems in wiring loom....

Never seen a mat or clt falling like that.

[quark2501]

How about TPS? It shows no movement when engine rev. Its the cam sensor you have a problem with, I had a problem with at loose connection on the cam sensor plug. It would dissapear and run rough, bending the 2 pins on the cam sensor itself fixed that problem, try it, dont think thats the problem, but easy to try.

[md323]

TPS isnt hooked up. the MAT and CLT thing bothers me too. I swapped to a V3 base board and it runs better, but still looses synce above 7500-7800 RPMS.

Im really stumped at this one

[quark2501]

How about the MAT and CLT on the V3? Is it still doing the drop on the stim? If the MAT/CLT problems are gone on the stim, then I would for sure thing about taking that wiring loom apart.
I sounds like the falling of MAT and CLT are related to Sync losses if you ask me, maybe the ground are really f.... in the loom.

[md323]

same issue on the V3, which is from my car which has no such issues. I have a feeling its the harness too.

[jimmyhoffa]

Did you ever resolve this issue or narrow down the cause?