Discussion and questions related to the course EFI Wiring Fundamentals
Hi, i have a megasquirt ms3 standalone and i a 2jzvvti engine, the problem that i am having is that when i am starting the car the rpm hit arround 5000 rpm at idle knowing that the throttle is closed. I had a log from the trigger and it seems to get a sync loss during the cycle, could i have a faulty cranckshaft sensor? I did wired a 10 k resistor for noise but the problem persist. I have the oem vr sensor.also the crancksensor is shielded.
Ps: i have a throttle body of Golf vr6 that has an actuator that i am using for antilag, i know it wont cause this problem but maybe it will i dont know, i calibrated the tps and it works fine.
Here is a log of my trigger, is it normal because there is a gap between the teeth that it is messing knowing that if you count the teeth it is 34/ 36-2 do the gap mean anything?
Fast revs at start usually means you have more air entering the manifold than you think. You say the throttle is closed. Is there an idle stop screw -- or any air bypass screws that could be open?
Is the actuator on the Golf throttle body really an air bypass (sometimes called Idle Air Bypass, or Idle Air Valve)? Perhaps you have it in the wrong state (fully open) when you start the engine. Or you have some other type of manifold air leak.
G'day Ibrahim. Just to confirm, your engine isnt physically revving to 5000rpm, you're just seeing a spike in the logs?
It seems like a lot of people have problems with the VR sensors on the JZ series of engines. Do you have access to an oscilloscope at all, can you get a scope picture of the signals?
G'DAY ZAC thanks for the reply, actually my engine was physically reving while the throttle was closed. I thought at first that the problem was with the vr because the throttle was closed completly while the engine was reving and i used a smoke machinr to detect any leaks, it seems the machine was faulty!! I detected a huge air leaks in the intake manifold! And the car idle perfectly! And my tooth logger tricked me, i thought i had a sync error!
Oh, wow, yes, no way it should be revving to 5000rpm with the throttle closed, must have been one hell of an air leak! Glad you got it sorted :-).
Hahaha yeh it was!! The problem was that i told my worker to install an aftermarket intake manifold and he kept some screw holes for vacuum open!! He made me loose my mind :) until i discovered the problem