mobythevan

Here is the link from Matt Cramer for the idle tuning tips on diyautotune: http://www.diyautotune.com/tech_articles/megasquirt_idle_tuning.html Here is the link to the original post in the MS forum: http://forums.hybridz.org/index.php/topic/100811-megasquirt-idle-tuning-tips/

I'll post a new thread in the FAQ area with Matt's link so it is captured as a sticky. Then this thread can continue with your questions and observations.

Its Ok if you don't have a relay board. In that case you should have the GB wire from the dizzy tied to pin 24 of the DB37. Pin 24 is the tach input. Also, the GB wire should have the pullup resistor to 12 volts. If you have it connected like this and you jumper D1 and D2 you should get a cranking RPM in tuner studio(or megatune). Like I said before make sure the 12 volts that powers megasquirt/dizzy/pullup resistor is on during cranking and during running.

Getting rpm should be the first priority, don't worry about messing with spark until you can see a cranking rpm in megatune/tuner studio. OK, the pictures you took of the board are pretty good so I can see that you have tachselect jumperd to optoin. XG1 and XG2 are jumpered together. Optoout is jumperd to tsel. That all looks good to me for using an 83 turbo dizzy. I would put jumpers in place of both diodes D1 and D2. Do you have the dizzy wired like this picture with the pullup resistor to 12volts? If so you should see rpm when cranking, so doublecheck that your wiring matches this AND that you have 12volts to the dizzy/pullup resistor/megasquirt when you are cranking.

Oh boy, this thread is on its way to the shed.....

I think your progress sounds good. I wouldn't worry about leaning out so much. Set it were it runs great. If you want to save gas you can by a prius.

Pin 24 is the tach input trigger. You do not need 12 volts on this pin to program firmware. You do need 12 volts to power up megasquirt which comes in on pin 28. If you have 12 volts on pin 28 you should be able to load firmware regardless of pin 24 being at basically zero. When you turn the key on, then one of the relays will switch on and it provides 12 volts to power the MS board through pin 28 of the DB37 connector.

I would think you would use a pullup resistor to 12 volts on pin 24 just like you do for a 83zxt dizzy install. If it is like every other optical trigger I have seen they all require a pullup.

I have been playing with the stepper IAC and trying to help my friend get MS2 on his Talon. So far no problems with MS3. I will add updates when I start running it on the LSx setup.

Also, let me know if you want this post or the link added to the FAQ area.

Sounds like what Tony D. experienced when messing with the 81 CAS and his timing was far off which was burning the mixture as it leaves the cylinder. Good anti-lag setup.

The v3.0 pcb doesn't support the stepper per se. MS2 and MS3 actually have stepper driver ICs on the daughterboards. The v3.0 pcb allows the 4 wires to be connected to the stepper, but you still need to driver IC.

My opinion after having several megasquirt cars for several years is that if you only drag race your car then skip the IAC. If you daily drive it and drive it at night or have AC/eletric fans/windshield wipers/etc then put a stepper IAC on the car. Right now I am setting up GM steppers on 3 different cars and I think it is worth it on a daily driver. Of course I did not have have IAC in the old days of MS1 because the board did not support it. But now that everyone is using MS2 or MS3 I would say everyone should have IAC since both support it. That is my two cents.

That doesn't make sense to me. A couple things about that statement don't add up. I assume you are revving the engine to 2000rpm while setting in neutral? If so, then it is highly unlikely the turbo builds any boost, even a couple pounds. Idle at 80-88kpa is way off from anything I have experienced. I am thinking your MAP sensor is wrong, installed wrong, damaged or using the wrong settings. I did not read over the thread again so this has probably all been mentioned before. It will be interesting to see what the shop figures out.

Once you take it to the pros and they fix everything can you please post up what the fixes were so the community can benefit from DIYautotunes time.

Good Work!

Here is some info from an old post by Matt Cramer: The resistor was there to protect the circuits on the older ones - if you have a new LC-1 (the one with the "dark thunderstorm" box), you won't need it. BTW, the resistor value was 470 ohm 1/4 watt Sounds like the resistor has not been needed for a long time.

Weird, I have been using the LC1s on a few different cars for years. There are two outputs if I remember. A yellow and a brown wire. I always hook one to my gauge and one to megasquirt. I think I always put the resistor in line to the megasquirt. Then open the LC1 software and program the outputs to be what I want. The only problem that I have heard of from my friend is that his O2 sensor goes out about once a year, but he has it mounted low in the pipe so I think it gets water built up in it. I'm not sure about the quality of the LC1 but it has worked fine for me.

Very good. You did a good job of sticking with it and making it through. Now its on to tuning

What is your timing advance at idle?

We are watching you work through the problems. Keep at it, you are making good progress. I don't have anything directly to add, but I will help when I can.

good luck and keep us updated

You can still use the mega log viewer and the stripped down version of ve analyze. I used it before I bought tuner studio. You make a log and then load it into log viewer and do the analyze.

Since you are using tuner studio I would drive around a bit and create a data log. Then use VE analyze to help you start tuning in your fuel table to reach the AFRs you desire under different operating conditions. Like 14.7 at cruise and 12.0 under boost. I think you are at the point to start tuning fuel.

The HEI modules stuff was for the really old v2.2 mainboard that did not support anything but fuel control.