Need help...

[rod2190]

For any of the responses given I thank you now... I had a problem with my ms2 extra I have an 86 635 turbo and I have rev limiter set to 6k but the RPM will not go over 5. It was not going over 3 but I backed out the vr sensor as much as possible and even loosened the bolts to the bracket and tried backing it a little more and I still cannot go over 5k rpm. It spits and backfires and will not go past that rpm in neutral or under load. If I haven't confused u or I am missing vital information in order for u to help me out please let me know I will happily provide it for u. I appreciate your time and help. Rod

[marc79euro645]

Have you verified the timing?
Was the motor running good before, or have you been in it? If you had the head off I would recheck cam timing.
Try datalogging the breakup to see if vr is falling out. If it is the vr, try tuning the pots(r51 and r56 iirc) Megamanual has a chapter devoted to it.
Are you triggering on rising edge or falling?
Valve springs can also make a motor not rev, if it's been sitting a lot.
good luck
marc

[rod2190]

Had the car running on chip and fmu for almost a year it's never done this before will get the info to you when I get to my laptop thanks

[rod2190]

Ign input is on rising edge

[marc79euro645]

Have you verified the timing?

[rod2190]

No I don't have a timing light, but car was running fine on motronic? If I get a hold of a timing light would I use plug wire 1 or 6? What is timing suppose to be at? Sorry for all the noob questions

[marc79euro645]

Sears Craftsman makes a decent adjustable timing light thats not too expensive.
You need to find top dead center on #1 plug, make a pointer that is fixed solid on the front where you can see it, and mark the dampener at tdc,with white paint. Hook up timing light to #1 plug wire. Start car and watch what Megatune, or Tuner studio says timing is idling at. Go under the hood and see what the timing light says. Then adjust trigger wizard to get software to say the same as actual timing(with timing light).
This is critical.
I suggest you print out the Mega manual,get a highlighter, and read more.
good luck
marc

[rod2190]

I just wanted to say thank you for taking the time to make a suggestion you are the only one who had a response and I really appreciate it I am going to take your advice and try it out and I will get back to you and let you know. I sent a data log to Peter from Pf Tuning and he told me that that the vr signal is too hot and that I will most likely need a change in the box itself but I will try your suggestion before I send the box back to him.

[marc79euro645]

Good knowledge on this board. I've sure learned a lot reading here. I just beat them to the answers is all.
Once you have verified timing with a timing light, try tuning the pots to get a stable vr signal.
http://www.megamanual.com/ms2/vradjust.htm
You'll get there. Megasquirt requires a lot of reading, but it was rewarding to me.
marc

[Kelvin]

In my experience with ms2 and m30 motor the crank position sensor must be of good quality and adjusted properly. Is there any loss of sync in your datalogs? The oem ecu is very forgiving, ms2 not so much.

[Nebraska_e28]

In my experience with ms2 and m30 motor the crank position sensor must be of good quality and adjusted properly. Is there any loss of sync in your datalogs? The oem ecu is very forgiving, ms2 not so much.

x2 on this

Check your datalog for lost syncs. I had a similar issue & replaced the vr sensor in addition to setting it as close as possible to the trigger wheel.

[rod2190]

My vr sensor is a brand new Hella and car runs better the further away the sensor is from the wheel.... ? I don't have any loss of sync but my vr signal is to hot to soon

[Nebraska_e28]

Can you describe 'hot'?

[rod2190]

No I cannot I was just quoting peter from pf tuning I sent him a composite log. I can send it to you if u would like to take a look at it?

[Nebraska_e28]

What are you using for an engine harness? Do the vr sensor wires run through shielded cable prior to reaching MS?

Can anyone comment if the shielding is grounded to the chassis via the harness>motronic box common ground?

[rod2190]

It's a plug and play unit for 059 ecu so I'm using factory harness. Vr sensor is plugged into one of my old flywheel reference sensor connections the grey one to be exact.

[rod2190]

I really appreciate your input btw

[marc79euro645]

I get the appeal of plug and play,but I would recommend a dedicated shielded cable from vr to ms. Ground the shielding as well.
marc

[rod2190]

The bmw harness isn't shielded? Any way one of you could send a link to a write up? Or maybe a few pics so I have an idea of how I should go about getting it done. It would be much appreciated.

[marc79euro645]

Get about 6 ft of shielded cable like this
http://www.ebay.com/itm/16-AWG-Teflon-S ... 1e9165bf5f

wire like this
http://www.megamanual.com/ms2/V3_ext_wire.gif

read this
http://www.megamanual.com/ms2/vradjust.htm