Mythbuster74

So I'm have a issue with the rpm signal, and not being able to get it to start. I would mess with the pots until I'd start getting an rpm signal, but by then the battery would die. Go inside wait for the battery to charge go out again and I'd basically have to start over fine tuning the signal. Then I found I was missing a diode that helped to smooth the power input to the MS. Was able to get a decently solid rpm signal but only pops through the exhaust and some sputtering. My battery charger has died so I need to get a new one, but has anyone had this rpm signal issue?

And also does anyone have a base tune for this setup? (Lm7, ms2 extra, 80lb dekas, ls1 intake , s475, everything else stock).

I know MS makes a base tune for you, but I've found other peoples timing tables to be very different and would like to have a kown good tune so I can rule that out.

Driving me crazy!!!

svslow

Check here for tunes. I don't think many people are using a straight MS2 set up but it would be very similar to a Microsquirt tune. You can export the tables from the tunes and import them into your. Did you not start with any base tune? If nothing has been set up then the ECU has no clue what to do any of the inputs. Open one of the tunes listed and compare it with yours.

I assume you are running wasted spark/batch fire?

https://sites.google.com/site/sloppy...irt-base-tunes

svslow

If you post your current .msq I could look at it when I get home.

Mythbuster74

Yes, logic level wasted spark. I've tried to use denmah's maps, but it has some craziness to it. For example his req fuel is zero? And a lot of the line graphs look kinda crazy.

I've tuned my dad's procharged BBC fuel only, so I know the basics of MS. I've posted the current tune I'm using. I'm not sure if it's a "good" tune because I've messed around with it so much that I don't remember if it's close to what I had to start with. I believe I got some of the tables by copying and pasting from denmah's stuff though.

svslow

Yeah some of his stuff does seem pretty iffy but they do work. I wasn't sure how much of a base tune you had. Looking at your tune will give me a better idea of what is all setup.

Are you using a stock crank sensor and 24x reluctor? Did you use shielded cable to for the wiring of the crank sensor?

Is this how you've got it setup?

http://www.msextra.com/doc/ms2extra/MS2-Extra_LS1.htm

Mythbuster74

Yep, 24x shielded audio cable with the shield grounded at the MS. And yes I have it on ls1 mode with the recommended logic spark output method, using the 2 MOSFETs.

svslow

Sounds like you have the essentials down. Have you thrown a timing light on it to see if its sparking?

Mythbuster74

Not with a timing light, but I have tested spark output with the MS test mode and they all spark. I also get a sputter like it's starting, so that leads me to believe that it is sparking.

svslow

Well that is a good sign if you can get all 4 outputs to spark in the correct positions. I'll take a look at the tune tonight and see if anything sticks out.

svslow

I completely forgot to take a look at this. Do you have any updates?

Mythbuster74

Well I got a new battery charger so testing can continue. New crank sensor just to rule this out and know I have a good one from now on. New battery because I was using a old one I had lying around and needed one for the build.

I don't understand what's happening in this picture though. As soon as it goes to start it instantly drops the signal and flatlines it.

svslow

I had a somewhat similar issue on my old 2.3 turbo set up. I could not get any signal from the VR sensor on my trigger wheel during cranking. The problem ended up being a failing starter which was generating a ton of noise interfering with the signal. New starter and cables fixed it instantly. Just a thought.

svslow

A tooth log is better to use to see what the crank sensor is actually doing. I rarely use the composite logger.

Mythbuster74

You got no signal at all? As in a complete flatline? Or it would go in and out? I also understand that the ls1 sensor is more of a Hall sensor but I have heard that bad starters cause noise issues. But if I have a signal while cranking but not when it goes to start I would think it's not starter right?

svslow

I would hardly get any signal. I rewired it multiple times, tried 4-5 sensors and nothing worked. Then I replaced the started and added an additional ground strap and it worked.

Mythbuster74

I'm pretty positive my ground and power scheme is pretty good. 0 gauge wire comes from the battery in the back to a positive post and then to the starter and an 8gauge wire inside the car to feed a relay bank, which feeds the fuse boxes. The ground is similar, comes to the front to a bolt in the body where another heavy gauge wire meets it and goes to the block.

The starter could be bad, it's used but I'd hate to throw the $100 dollars at it for it not to work haha. I ordered a better vr condtioner board so I can rule out my soldering and also have a upgrade. Maybe I'll make a video of my wiring scheme and post it so people can have a look.

Mythbuster74

If anyone comes across this thread the solution was to install a jbperf dual vr condtioner board. Apparently I must of over heated something during soldering the board, or had a defective component. Anyways if you have rpm signal problems I highly recommend the upgrade for ms2