Yet Another No RPM Thread
 

Some background:
1988 TII
13BT
MS2v3.0 firmware 3.2.5
Zeal card and wired/jumpered per DIYAutotune's instructions.
All ignition wiring has been triple checked from the harness pins to the engine bay connection.
CAS passes FSM resistance spec.
CAS passes FSM spec measured at the MS harness pins as well.
CAS wired using 22awg 4 component shielded cable, grounded with the sensor ground wire at the fuse panel ONLY.
Tune figured per Aaroncake and DIY's instructions

My problem:
Since the car isn't quite ready to start and drive, I wanted to test the ECU and wiring by spinning the CAS. Using a drill and spinning by hand, I get no RPM signal whatsoever. It just sits dead still at zero.
I have checked the wire color per my wiring diagram and checked continuity between the ECU pins and CAS pins several times. My wiring is correct per DIY's instructions.

Here is a link to my tune:
https://www.dropbox.com/s/kvkc9olq25...5_06.24.45.msq

Is there anything I'm overlooking?
Tune look okay?

Thanks for any help!
Alex

For some reason your MSQ won't open in TunerStudio. Just hangs.

That said, check the output of the Zeal card with a voltmeter while you spin the CAS. You should see swings from about zero volts to about 5V. This is best done with a scope so you can see the wave form.

If you get these swings on both VR circuits, then there is a problem with your software settings most likely.

Here's a new link, see if that works. There are 3 ignition-related pins on the Zeal, VR2+, VR2-, & VR2 Out.Which one do I check voltage from? I don't have access to a scope and the car is immobile so I can't bring it to work. Will a multimeter checking voltage between one of these pins and ground do the trick?

https://www.dropbox.com/s/pu3y460ec1...7_10.59.37.msq

Thanks

Worked this time.

Your ignition capture settings look fine.

With your meter, you'd check for 5V pulses at the Zeal card VR2 Out. That is the conditioner circuit output to the processor.

You're using the stock VR conditioner on the V3 board as well, correct? Is it jumpered correctly? ie. Not set to optical?

I will check the VR2 Out today. I am using the original VR circuit and it's jumpered per DIY's instructions. We'll see how this goes

So, I checked voltage between VR2 Out and ground and saw no change when I spun the CAS. Any other ideas of what else to trouble shoot would be much appreciated.

No change would indicate the Zeal board is not operating.

Check it for power at the appropriate pins.

The output circuits on the zeal are working, so I would guess it has power. I will check continuity between the zeal board and all of its connections on the MS board after work.

Checked continuity between the Zeal and MS and everything looks good. I also checked continuity between the DB37 pins (25&26 for G+/G-) and the pads on the Zeal and all's good.

I've also check continuity on both sides of each jumper to make sure I don't have a cold solder joint or broken wire.

My gut says somethings up with the MS2v3 VR circuit. I double checked the Megamanual and all of my jumpers look correct.

My jumpers for the v3.0 VR circuit are as follows:

Tachselect>VRIN (also has continuity to Pin 24 [NE+])
TSEL>VROUT (also has continuity to one of the v3.0 VR chip pins)

-Not sure where Pin 2 terminates for NE-

Where is the negative side of the v3.0 board VR circuit terminate?

I'm at a lost, guys.
Anyone have any ideas of what else to check?

Thanks

I have somewhat of an update. Thanks to elturbonitroso, we were able to track the problem down to the Zeal board. By temporarily changing the trigger settings to Basic Trigger, we were able to get an RPM signal from the inboard VR circuit. In "Toothed Wheel" setting, we noticed that whenever you'd hold the VR2OUT wire from JS10, and RPM signal would appear when you spun the CAS. We assumed it was a cracked wire or bad solder joint.

Today, I pulled all my jumpers to the Zeal card and resoldered them with new wire and better strain relief. I connected the CAS and Tunerstudios and still no RPM.

THE WEIRD PART:
If I TOUCH the VR2OUT wire, I get a signal. I dont have to wiggle, bend or move it, just TOUCH it. For shits and giggles, I put on a pair of rubber gloves and touching it wouldn't work. I tried grounding the CAS to see if that'd help and it did nothing. All my solder joints look fine, used heavier gauge wire this time, and I have voltage and continuity between the Zeal ground/5V/12V pads and the v3 board.

Anyone have any ideas?

you still have a cold joint on the vr2 output area

Like he said below you have a cold solder joint and need to put some Flux on the joint and remelt the solder so it makes a better connection.

I re-resoldered the VR2OUT wire, at the Zeal and JS10. It's STILL not working unless I touch it.
It gets even weirder.
If I poke it with something like a pencil, nothing. I touched the VR2OUT wire to the rubber handle of my hot(powered) soldering iron and it started working. When I unplugged the iron and tried again, nothing. When I plugged the iron back in, touching the handle to the wire worked again.
I'm thinking there is some sort of capacitance issue that I don't understand. I checked my grounds again and everything looks good. I am so lost.

Thanks,
Alex

try this put the wire that go to out2 directly to pin 14 on the lm1815 chip.

So, I finally got it working without using magic or telekinesis. I ended up using the VR1 circuit on the Zeal card instead of the suggested VR2 per the instructions. I jumpered IAC1A/B to VR1+/- and VR1OUT to JS10 and it worked like butter. Something must be fubar in the VR2 circuit or maybe the LM chip is dead. Either way, I hope to start the car soon and see this thing run!

Thanks,
Alex