MS3X cam fault, and another problem

BlueCuda · Post by **BlueCuda** » Sun Jun 28, 2015 8:31 pm

Hello

I am running MS3X on a 360 Chrysler in my 68 Barracuda. I am running D585 coils, Jeep 4.0 Cam Sensor, 36-1 wheel, Cherry Hall effect crank sensor.

Right now I am running ignition only, so I am still using a carb(I know I know) but I will change that after I get some more money saved up but I needed a new ignition so I went ahead and installed the MS3X I built.

It has been running great, first start went off without a problem, and I have put 30-50 miles on it with little trouble.

However, I have not been able to get my cam sensor to work. It always comes up as a cam fault as soon as I start the engine. I even matched my settings with another user that is using the same cam sensor on his car. I am getting 5V to the sensor(hall) but I only get 2.5ish volts coming out of it, I tried another sensor and got the same result. Any ideas here? I was able to operate sequential on stim boards no problem so something is amiss in the real world install.

Next issue, today on my way back home I ran into what I thought was a problem that would strand me. I had made a modification to my very basic timing table and burned it to the MS. When I started the car I got one little hiccup but it did not show up as a sync loss. Later in the drives as I pulled up to an intersection it went nuts, backfired, and I could hear what I assume was my fuel pump relay going insane. I shut the key off, turned it back on and it fired up only to do the same thing 1/2 mile down the road. It sounds like it loses the firing order as it backfires out both ends then the fuel pump relay goes insane on off. I popped the hood, checked my connections, tightened my crank sensor connection that didn't seem loose and it fired up OK and got my home another mile where it ran in the garage fine. I was not logging at this time unfortunately.

See attached MSQ and composite log I did while cranking today.

Matt Cramer · Post by **Matt Cramer** » Mon Jun 29, 2015 6:59 am

The cam appears to be reading correctly; this may be a TunerStudio settings glitch. Try reloading your dashboard.

On the other issue, were you able to capture it to a data log?

BlueCuda · Post by **BlueCuda** » Mon Jun 29, 2015 8:06 am

Thanks for the reply Matt!

No I did not get a log for the second issue. Had I not been in the right hand turn lane in busy traffic I would have started one as soon as I got it running again but I was in the way lol.

How do I go about reloading the dashboard? Thanks!

Matt Cramer · Post by **Matt Cramer** » Mon Jun 29, 2015 10:47 am

Right click on the dashboard, select Load/Save, select Load Dashboard, and select one of the default dashes. (Note - in the Lite version of TunerStudio, you may need to make a new project.)

BlueCuda · Post by **BlueCuda** » Mon Jun 29, 2015 5:23 pm

Thanks for the Replies Matt, that is why I bought all of this at DIY.

I attached another composite log, this one is from a start and run as opposed to just a cranking log. It actually looks like the cam sensor drops out once it is running.

If I read the manual correctly the Jeep 4.0 cam sensor is actually a poll sensor, its 180 on and 180 off. I originally set it up this way and I had the cam fault. I then copied the settings setup from user Redmist since he is running the same sensor, no luck then as well and that is the way it is currently setup. I have checked and rechecked that it is getting 5V and it is.

Now as to my other problem I found my MS grounds on the back of the heads to be loose, they weren't floppy loose but the bolts were not even finger tight. I tightened them up and I hope that was my issue.

Thanks again
1

Matt Cramer · Post by **Matt Cramer** » Tue Jun 30, 2015 5:37 am

Ok, looks like you've got a legitimate cam fault in that new composite log. Try spinning the sensor by hand with the key on and engine off, and see if its voltage drops to 0 over half its rotation.

BlueCuda · Post by **BlueCuda** » Tue Jun 30, 2015 9:25 am

It does read 0 on half of its rotation. I have another sensor that I have used on the bench but not on the running engine I will try it out although they both do the same on the bench.

Does the voltage return matter? The sensor is getting 5V but only returns about 2.5 or so, both sensors do this.

Clark

Matt Cramer · Post by **Matt Cramer** » Tue Jun 30, 2015 11:47 am

Yes, voltage return matters. Try a 1K resistor between the supply voltage and signal wires.

BlueCuda · Post by **BlueCuda** » Tue Jun 30, 2015 12:15 pm

Ok Will do, thanks!

BlueCuda · Post by **BlueCuda** » Tue Jun 30, 2015 12:16 pm

The sensor is setup to be just on the beginning of the signal side when the #1 tooth is on the crank sensor, is that correct? and will that cause a fault? Thanks

Matt Cramer · Post by **Matt Cramer** » Tue Jun 30, 2015 1:29 pm

Make sure you don't have either edge of it lined up with the sensor gap. It would be best to get the active edge at least 2-3 teeth away from the missing tooth.

BlueCuda · Post by **BlueCuda** » Tue Jun 30, 2015 5:23 pm

The resistor seems to have fixed the problem. Full RPM sync was lit up green today. There is actually a noticeable difference in idle quality when its working in full sequential. Thanks for the help!

I attached another composite log.

BlueCuda · Post by **BlueCuda** » Wed Jul 01, 2015 5:31 am

So now that the resistor made it work what would be the reason behind that? Is there a place in the ECU I can add the resistor internally? Thanks

Post by **jsmcortina** » Wed Jul 01, 2015 5:50 am

Which resistor?

James

BlueCuda · Post by **BlueCuda** » Wed Jul 01, 2015 5:59 am

I put a 1k between the 5v reference and cam sensor input for the ms3x card.

Post by **jsmcortina** » Wed Jul 01, 2015 6:08 am

There's a jumper on the board to do exactly that. It's in the manual.
http://www.msextra.com/doc/pdf/html/MS3 ... .3-83.html (scroll down)

James

BlueCuda · Post by **BlueCuda** » Wed Jul 01, 2015 9:03 am

Hmmm looks like I misinterpreted my sensor type. I had the JP7 jumpered at one point when I was running it on Stim boards Thanks for the response.

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