NO Crank Trigger

[TLP_1JZVVTI]

Hello all! As the title states, I have no crank trigger. Basics of the setup below.

Setup:
1JZ VVT-i
LS1 Coils
MS3x

Car ran fine for months and months and all of a sudden it just quit. Felt like a charge pipe blew off, or sensor went out, because literally it was running fine and one second, nothing. Got it back to the shop and went through Tuner Studio and ruled out the basics; injectors, coils, etc. Fuel pump comes on, injectors click, can trigger coils via tuner studio, etc. Map sensor is working, etc. etc.

As I crank the car, there is no RPM reading, and no crank signal. Tested the crank sensor, tested out fine, but thought I would go ahead and replace it anyways as a piece of mind and why not have a extra sensor laying around? Brand new Toyota sensor, nothing. New Toyota cam sensor, again as a piece of mind and spare parts, nothing.

Pots were set prior to tuning and even after dyno tuning car ran like champ. Did 1/2 mile drag races, spirited driving, etc. no flaws. I was backing out of a park space and pulling away while still in the parking lot and the engine just dies. I referred to the MS3x diagram and checked all of the wiring to the crank sensor. 12v source is good and providing voltage to ECU. Ground for the crank wiring is good. OHM the wires out and was getting a .2ohm reading. Continuity test shows no breaks in wiring.

Been messing with it for weeks and I am out of ideas, it has to be something simple for it to run 4-5 months with no flaws and then all of a sudden it just quits. Just wanted to see if any you guys had some pointers/opinions? Can the ECU itself be bad? Thanks!!!

[Matt Cramer]

Can you get a signal on a JimStim?

[TLP_1JZVVTI]

Can you get a signal on a JimStim?

I'm pretty new to MS3x tuner studio. What do you mean by JimStim? Is that a tab or setting in tuner studio?

[Factor9RB25DET]

here is a link for reference.... http://www.msextra.com/manuals/stim/

JimStim:

It simulates:
CLT sensor
MAT sensor
TPS
O2 sensor (narrowband or wideband)
spare potentiometer for additional sensor

Many RPM signals equivalent to OEM trigger patterns with both crank and cam outputs. ‘Hall’ or ‘VR’ type signals.

It has LEDs to indicate:
– the two output channels of the batch-fire Megasquirt
– two bi-colour LEDs for stepper idle
– fuel pump
– idle output
– four spare LEDs for spark or fuel indication..

[TLP_1JZVVTI]

here is a link for reference.... http://www.msextra.com/manuals/stim/

JimStim:

It simulates:
CLT sensor
MAT sensor
TPS
O2 sensor (narrowband or wideband)
spare potentiometer for additional sensor

Many RPM signals equivalent to OEM trigger patterns with both crank and cam outputs. ‘Hall’ or ‘VR’ type signals.

It has LEDs to indicate:
– the two output channels of the batch-fire Megasquirt
– two bi-colour LEDs for stepper idle
– fuel pump
– idle output
– four spare LEDs for spark or fuel indication..

Ok, so from what I've gathered, the JimStim is pretty much a external circuit board that plugs into the MS3x so that you can determine if there is a true signal from the sesnors. Does a lack of crank trigger signal and rpm reading zero in tuner studio not enough to determine that there is no signal? I am going to log some data and the tune later and post as well.

[TLP_1JZVVTI]

Here are the logs as promised. Let me know what you guys find! Thanks.

[Matt Cramer]

The JimStim will allow testing the unit off the car on a simulated crank signal to see if the problem is in the ECU or the wiring / sensors.

[TLP_1JZVVTI]

Before I pull the trigger on one, I've posted two data log, I was wondering if anyone on the forum has some input? Thanks.

[Matt Cramer]

The logs show, well, no crank signal.

[TLP_1JZVVTI]

I am just completely loss. New sensor, new wiring, yet nothing.

[Matt Cramer]

So, have you tested the ECU on a JimStim yet?

[TLP_1JZVVTI]

So, have you tested the ECU on a JimStim yet?

Have not, not sure if I want to spend $100 on a JimStim and then come to figure the ECU is bad instead of applying that money toward something else. Does DIY rent JimStims?

[Raymond_B]

You could send the ECU to DIY to be checked out


Sent from my iPhone using Tapatalk

[Matt Cramer]

We can test ECUs that we originally built but are not set up to work on customer assembled units.

Sorry, we are not set up to rent JimStims.

[Raymond_B]

We can test ECUs that we originally built but are not set up to work on customer assembled units.

Oh gotcha, I did not know that, sorry.

[DaveEFI]

So, have you tested the ECU on a JimStim yet?

Have not, not sure if I want to spend $100 on a JimStim and then come to figure the ECU is bad instead of applying that money toward something else. Does DIY rent JimStims?

If there is a problem with MS, it's likely to be on the tach input you're using, so a cheap fix. A stim is the easy way of generating a test tach signal on the bench to verify this.
You could always sell it after use. Or, of course, send the MS off for testing/repair.

[Rick Finsta]

Once you've got a JimStim you'll use it on everything. You can use it to power things like O2 controllers or outboard ignition setups on the bench for testing, loading firmware on the bench, testing other ECUs for friends, for testing new I/O setups and sensors... It really is an invaluable tool for EFI.

[TLP_1JZVVTI]

Sent ECU in to DIYAutoTune and they were able to load new firmware onto the ECU and is now receiving a crank signal.

Plug it back into my car, make sure the correct tune was loaded. Still no crank trigger. These are the things I've done:

1) New Crank Sensor (Toyota OEM)
2) New Cam Sensor (Toyota OEM)
3) Checked continuity on crank wire to plug, confirmed that there is no break in the wiring.
4) New connector for the crank sensor

I am completely lost. Has anyone else had reliability issues out of their megasquirt setup? Specifically for Toyota JZ engines?

[DaveEFI]

Thing is that simply changing a crank and cam sensor without first being certain they are faulty is pointless.

[TLP_1JZVVTI]

Thing is that simply changing a crank and cam sensor without first being certain they are faulty is pointless.

Yep. Only reason I did it is because I had access to the parts.