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MS-II build underway...questions

Posted: Wed Jun 06, 2007 5:03 pm
by kredden
Well, I've finally gotten around to starting the MS build. I'm taking it slow and I've gotten up to the part where I tested the serial port connection. So far I've got two things that are annoying and they both are related to the DB37 connector.

The first is that the screws that hold on the front plate of the connector on the board and the ones on the stimulator collide, I have to unscrew one set to connect the boards together, whats up with that?

The second is that I haven't soldered the DB37 to the MS-II board as I've read in a few posts that it is hard to get out once in so the only way I've found to make the pins connect to the circuit board is to shove some small gauge wire into each hole that actually has a connection to the circuit board. The problem is that some of them keep falling out. Is there a better way to do this or should I just solder the pins that are connected and then try to undo them later? I tried to bend a couple pins to make better contact but I'm afraid I'll break something on the connector.

Thanks,
Kevin

Posted: Thu Jun 07, 2007 2:10 am
by Murray
Kevin based on your description I guess your planning on installing the MS board directly inside the old L-Jet case as Steve R did in his wrte-up ?
I had the same concerns about the DB37 and decided to build mine slightly differently.Attached is an image I borrowed from somebody on this site (sorry can't remember who to give the credit to ) I decided that having the DB37 permanently available for hooking up to the stim was important and in hindsight it was the right decision.All I have to do is unscrew the MS case from its mounting plate and unplug the DB37 and I can bring my MS into the house for testing on the stim.This can be an important advantage as you progress towards getting you car running well.The other alternative is to get a spare L-Jet "male" connector and wire it up to the stim if you want to become really familiar with the wiring diagrams !

Posted: Thu Jun 07, 2007 3:39 am
by kredden
Murray,

Thanks for the quick reply. I like what you did, makes a lot of sense. I was wondering how I would deal with hooking up the stim in the future if something broke!

Kevin

Posted: Fri Jun 08, 2007 6:02 pm
by kredden
I'm up to step 50 now (and all testing has passed up to this point), from here do I go with 50a (To install the Hall/optical input circuit (or points without a coil connection)) or 50b (For triggering off the coil negative terminal/points)?

I'm assuming 50b?

Thanks,
Kevin

Posted: Sat Jun 09, 2007 2:31 am
by Murray
Kevin you should probably go with 50a.The ignition signal from the hall sender in the distributor is much "cleaner" and is easier to work with.You will have to make some small modifications to the car's wiring (pull-up resistor) when you install your MS in the car but we''ll guide you through that process when you get to it.

Posted: Sat Jun 09, 2007 4:37 am
by kredden
Thanks, will do.

So by going this route does it make it much harder to swap back to the L-Jet in the event that something goes wrong with my MS? I'm planning on going to this years convention with the MS in the car but don't want to get stranded in the middle of nowhere because one of my solder joints fails!

Kevin

Posted: Sat Jun 09, 2007 5:31 am
by ar4me
If that is a concern, why not build a spare unit and keep in the car? Affordable enough, right? If you are in CA, watch out for smog. Do you guys have MS maps available that have been proven to pass CA smog?
Jes

Posted: Sat Jun 09, 2007 5:33 am
by kredden
Don't know if its affordable until I actually have it working :-). As for smog, no, I'm in NH, where they don't know how to spell smog.

Kevin

Posted: Sat Jun 09, 2007 5:59 am
by ar4me
kredden wrote:As for smog, no, I'm in NH, where they don't know how to spell smog.
Lucky you 8) I suppose it is only the ECU you would need to double...??? That is mostly your own time, right? For a couple hundred it may be worthwhile having a spare for the long road trips if you are concerned.
Jes

Posted: Sat Jun 09, 2007 6:29 am
by kredden
True, but I already have a spare with the original L-Jet if I don't get rid of any of the old connections. Might still require some work to swap over (TPS, AFM, etc but at least I wouldn't be stranded.

Kevin

Posted: Sat Jun 09, 2007 7:02 am
by Murray
Kevin, I approached this whole project with the same concerns as you (being able to swap back the L-jet if necessary),In 2 years use I've never had to do that.In fact last summer I decided to plug the L-jet back in to compare and I was surprised how "dead" the response was compared to MS.
You can keep all your existing wiring intact and simply run parallel circuits for the ones that are unique to MS.For the hall-effect pickup this is really easy to do if you have a spare 3 pin plug (the one that takes the signal from the distributor).

Posted: Sat Jun 09, 2007 7:24 am
by kredden
Excellent, just the answer I was looking for. I'm pretty sure I have one of those plugs, just need to dig through my pile of wiring harness spares.

Just started raining here so is a good day to get some more soldering done...

Thanks for your help.

Kevin

Posted: Sat Jun 09, 2007 4:09 pm
by kredden
Bunch more questions (some I'm already well beyond but should ask anyway!):

Step 22 - I assume we don't use an IAC stepper motor so I just ignored step 22.

Step 50.a.v - "If you have a Hall sensor or optical sensor, do not install D1, put a jumper in its place."

I jumpered this, correct?

Step 50.a.vi - "For most installations, diode D2 {1N4001DICT-ND, the marked 1N4001} is not needed. Do not install D2, install a jumper (made from a snipped off lead) in its place."

I jumpered this, correct?

Step 50.a.viii - "Leave the C12 location empty - DO NOT jumper it. This is located above "Bowling" in the copyright notice. This capacitor may need to be installed and/or the value increased if there are noise problems with the tach signal - values up to 0.1uf will work. The 0.001uf value is a good starting point."

I think this was one of the mods in Steve's writeup, do I need to do something here or just leave it empty?

Step 54 - "Install and solder R4 and R7 {2.49KXBK-ND, 2.49K, red-yellow-white-brown-brown). These are the temperature sensor "bias" resistors."

It looks like we are supposed to use 2.2K resistors instead of the 2.49K resistors included in the kit, is that correct? If so I forgot to order some :-(, hopefully Radio Shack has them.

Step 59 - "Install and Solder D4 and D8 {1N4748ADICT-ND} - observe the proper polarity. These are located beside MOV1, a bit further away from the DB37 connector. (Note - do not install D8 if you are using a PWM idle valve.)"

I assume we do not have a PWM idle valve so I leave D8 out.

Step 65 - This is the big honkin step on installing the high-current ignition driver circuit. Do I have to do any of this step?

Step 69 - PWM flyback dampening, I assume I want to do this step as I'll be running the stock injectors, at least for a while yet.

Step 71 - I assume I want to do this step to install the current limit circuit for driver FET protection?

Thanks,
Kevin

Posted: Sun Jun 10, 2007 1:50 am
by Murray
Kevin - affirmative on all the steps with the following exceptions:
Step 54 - "Install and solder R4 and R7 {2.49KXBK-ND, 2.49K, red-yellow-white-brown-brown). These are the temperature sensor "bias" resistors."

It looks like we are supposed to use 2.2K resistors instead of the 2.49K resistors included in the kit, is that correct? If so I forgot to order some , hopefully Radio Shack has them
No need to worry about this.When you set up your .msq with Megatune there is a tool to calibrate the thermistors used by the CLT and IAT.Use:
-20 - 9500
+20 - 2500
+80 - 350
and they'll work fine.
Step 65 - This is the big honkin step on installing the high-current ignition driver circuit. Do I have to do any of this step?
Yes you need this to control the ignition coil.

Posted: Sun Jun 10, 2007 6:33 pm
by kredden
I goofed on this one, didn't read it right:
Step 59 - "Install and Solder D4 and D8 {1N4748ADICT-ND} - observe the proper polarity. These are located beside MOV1, a bit further away from the DB37 connector. (Note - do not install D8 if you are using a PWM idle valve.)"

I assume we do not have a PWM idle valve so I leave D8 out.
Not using a PWM idle valve so D8 SHOULD be installed :oops:


I've got all the soldering done now but in testing it with the stim I can't get the stim IDLE LED to turn on that I think is used to denote a fast idle. The v3 build instructions say this is supposed to come on when the temp is < 145 degrees but mine doesn't. Any ideas?

Kevin