Megasquirt and Variants Running Thread

[cordes]

Well, crap. It didn't start after I returned home from church today. It's getting zero crank or cam signal when I attempt to log it. However, if I jumper power to the crank sensor and look at the signal with my oscilloscope it puts out ~10v square wave. That was with the MS unhooked and a pin in the connector to back probe it with the ground hooked up to the sensor signal ground.

I'm at a loss on this one. I'll be calling DIY autotune tomorrow to see if they have any suggestions. I'm wondering if feeding the hall sensors off of the 5v reference signal didn't damage the unit somehow?

[tryingbe]

Every Microsquirt is different so it's very difficult to troubleshoot without fully understand and see the quality of installation. Did you solder, did you crimp, size of wires, did you use new or old wires, all those make a difference.

When I did my built, I used new wires for ALL engine harness and crimped it all. I used on 5v to feed MAP, TPS, and Crank Sensor and One sensor ground to ground them all.

The problem followed, so what are the parts you re-used? I did NOT want to use the factory HEP for this reason.

Here is the diagram I made for my car.




As for Idle, I started with a on/off solenoid, then PWM Ford Idle Valve, then to PWM turbo Volvo BOSCH Idle Valve. Solenoid works great but didn't supplied enough air for a/c compressor and a/c fan, the ford idle valve leaks at Idle, and the Volvo BOSCH Idle Valve is what a TURBO Volvo uses, good enough for my car. All mentioned here. http://www.turbo-mopar.com/forums/sh...ht=microsquirt

Idle is just a vacuum leak, I drilled/tapped the pre-turbo pipe/after air filter then ran a line from there to one of the port at intake manifold. Used a hose that can withstand pressure as well as vacuum. I plugged the throttle body IAC hole for good.

[cordes]

Thanks for all that. I bought the 8' harness and I used 99% new mils spec wiring for things I needed to add, and new connectors, of which I needed very few as the MS has a map and baro sensor integrated into the unit. The only thing I reused were the connectors with pigtail wires for the LS coils, and then only a couple inches of each one. I did crimp every connection, and I used either genuine Thomas and Betts barrel splices or open barrel splice connectors with the "proper" Delphi crimper. I did test all of the crank and cam trigger wiring with my Load pro, and it checked out.

I spoke with Randy at DIYautotune today. He suggested that I should have been able to use the 5v reference signal or a switched 12v signal for the crank trigger sensors. After I told him that I checked the wiring with my Load Pro to verify a good power wire and sensor signal wire, along with the fact that I get a nice square wave on the scope, he said to maybe try turning off the pullup resistors.

I turned off the pullup resistors tonight and the car fired right up. It ran for some time, though with a little loppier idle than before. I made some adjustments to idle settings and attempted to apply the changes by cycling power and restarting the car. Once again, it was dead as a doornail and wouldn't see a crank signal.

Upon seeing no crank signal in Tuner Studio, I immediately removed the connector and hooked up the oscilloscope. It showed a very nice square wave of around 6v or so.

At this point, I'm inclined to believe that the unit is internally faulty. Nothing else would explain how the wiring would check out good, and the oscilloscope would generate a signal without fail, while the car sees zero crank signal. The one thing I'm worried about is that this unit will test good on the bench for the guys at DIYautotune but it will continue to intermittently fail in real world use. We'll see...

[cordes]

I spoke with my father tonight who voiced concerns that the hall sensor could be putting out a nice signal for the scope with no real current flowing through it, but that even the MS trying to read it might be enough to make it a bad signal. I'll take a spare sensor and see if I can hold it up to the trigger wheel while it's cranking to generate a signal. If I can swap back and forth with a reliable change, then I'll hesitate to send off the MS to DIYatuotune and perhaps swap sensors to put on some more miles. I guess either way it'll tell me if my unit is bad since the wiring tests perfectly with the Load Pro.

[wallace]

What hall sensor are you using?

[cordes]

What hall sensor are you using?

I'm using this one from Littelfuse

https://www.digikey.com/en/products/...pGI2NBBEAugL5A

ETA: My alternator either died, or the alt control in the MS stopped working. I'll probably take the alternator to get tested tonight. I'll be sending off the ECU to DIYautotune, as I'm fairly certain after further testing that the unit is bad.

[wallace]

Ditch that sensor. Pony up for the diyautotune one. I had lots of funkiness using the little fuse sensor. Look at the literature that came with the sensor it's got some circuitry .. the ms doesn't like that for some reason.

You can read about it in my LSC build at this link: https://www.theturboforums.com/threa...ln-lsc.388470/

[cordes]

Ditch that sensor. Pony up for the diyautotune one. I had lots of funkiness using the little fuse sensor. Look at the literature that came with the sensor it's got some circuitry .. the ms doesn't like that for some reason.

You can read about it in my LSC build at this link: https://www.theturboforums.com/threa...ln-lsc.388470/

I read through that build. That's a lot of work for sure, but I'm also sure it will be a very fun ride when you're done.

What problems were you experiencing with the littelfuse sensor? The one I have in Joy's Daytona runs super well, but I could see this one being a problem.

[tryingbe]

I'm using this one from Littelfuse

https://www.digikey.com/en/products/...pGI2NBBEAugL5A

I used the Cherry sensor. https://www.diyautotune.com/product/...threaded-body/

Here is a better priced one. https://lms-efi-llc.myshopify.com/pr...-effect-sensor

[cordes]

I need to search around and see if this is one of those things where one can purchase from Ali Express or the like for ~1/3 of the cost of other places.

Here's a place purportedly selling them for super cheap. If they're legit, that would be great if it's a sensor that works.

https://www.hawkusa.com/manufacturer...ffect/gs100502

[wallace]

It was breaking up under load and losing sync. The diy sensor has no electronics other than the hall effect.

[cordes]

It was breaking up under load and losing sync. The diy sensor has no electronics other than the hall effect.

Thanks for the info. Mine was just breaking up, period. It will be interesting to see what DIY has to say about it, as even when it ran last, the alternator stopped charging and since it tested good, I'm guessing that the ECU gave up controlling it. We'll see.

[wallace]

What MS are you using?

[cordes]

The new(er) MS3Pro Mini.

[cordes]

They tested the unit right when they received it. It apparently tested good, so I guess the sensor isn't outputting a clean enough signal for the MS. I ordered two sensors from DIY Autotune and will install them upon arrival. I'll hopefully have everything together by this upcoming weekend. Good times.

[wallace]

I'll be interested to see you get it running. What engine is this on?

[cordes]

I'll be interested to see you get it running. What engine is this on?

Just the stock engine that came in the Shelby Lancer. I have it running really well in my wife's Daytona with the TII converted engine that's in it. It runs Microsquirt and I had zero issues with anything when doing everything essentially the same way. We'll see, but I would think everything should have been much easier the second time around in regard to getting it up and running.

I'm not holding my breath that this will go well, but I'm not going to give up at this point. I have hundreds of hours into getting this car to run right. Almost all of it has come in the form of testing every electrical component on it so many different times. The fact that this hasn't been fixed or made to run correctly is mind boggling at this junction.

[wallace]

I hear you. These are the worst problems to sort out. Is it losing sync in the log when it occurs?

[cordes]

I hear you. These are the worst problems to sort out. Is it losing sync in the log when it occurs?

It was losing sync when cutting out. I changed the power feed to the hall sensors from the 5v reference to a switched 12v signal and that cleared up the miss. However, I'm now experiencing an intermittent total loss of signal. When it runs, it gets signal and runs like a top. When it doesn't run, there is no signal detected by the unit whatsoever.

I did check the hall sensor with my scope, and it saw a pretty good signal even though the computer detected nothing. There was a little horn on the right side of the square wave, but it didn't look too bad.

My new sensors arrived from DIY autotune today, and the MS should be back tomorrow. I'll change out the crank sensor and go from there. It will be 3-4 tanks of gas before I feel comfortable with the setup at this point. Good times.

Thanks again for all the help with this. Your build log was very informative and helpful.

[jpcturbo]

Maybe the car is simply cursed. I say replace every piece of copper on that car and run dedicated grounds from each system to the battery! Are there any rust issues causing continuity issues with the chassis?

Jeff