Matt Cramer

Try wiring red to switched 12 volts instead of VREF; this will get a stronger signal. Also make sure the gap is 0.040" or tighter.

If the running value is different from the off value, check the ground. The ground needs to be run to the ECU sensor return and not a chassis or engine ground.

I'm sorry the harness was missing these pins; they should have been populated. Email me at websales@diyautotune.com if you need any parts to fix it.

For the first question - yes. You can even leave the mechanical advance in place as it will help with rotor phasing. You'd use a timing light to set the timing. Just adjust the Tooth #1 Angle setting until the timing you see on the timing light matches the timing in TunerStudio.

The MS3-Pro does not have true OBD2 support, but if you're looking to stream the data to a dash gauge, there's some options here: http://www.diyautotune.com/tech_articles/megasquirt_displays_and_dataloggers.html It does have a Check Engine function that can detect many common sensor failures and has some limp home capabilities. MS3-Pro would require a cable operated throttle and does not control an automatic transmission. We do have some separate options for trans control if needed.

The OEM ECU is pretty well hacked, but doesn't deliver some of the features you can get with a decent standalone like individual cylinder tuning or various race features like timing retard from launch. The OEM wiring harness ties into a lot of things and needs some pretty extensive reworking for a swap. I'm a bit biased as a forum sponsor but an MS3-Pro ought to work great on this motor. I'm using one on an LS swapped '72 Chevy pickup myself.

I strongly don't recommend using alpha-N fueling on a turbo car. The only exception is if you are using it as a secondary load on an engine with ITBs. I'd need to see a log to see what's up with the acceleration enrichment.

First try reloading the firmware and loading a tune from before the problem happened - it could be a setting change accidentally stuck a spark channel fully on.

This is a sensor input issue, so dwell should not have an effect. It's sometimes missing a tooth. Are you able to get an oscilloscope on it, by any chance?

If we built the MegaSquirt and it was ordered with a KnockSenseMS input, the pin will be noted on the receipt. If this was added later, there will be a wire from either JS4 or JS5 to the pin to be used for the KnockSenseMS. Unused stepper outputs can be used for relay control or tach output. These features weren't around when the board was designed. The MegaSquirt was designed to be a DIY system that was easily hacked. The original hardware and code base had a fairly limited feature set (in the case of MS2, two fuel channels, stepper IAC, and one spark channel), but coders soon found the processor could support a lot more features than that, and the board had pads brought out to allow adding these things. However, building a ready to run system with a lot of these outputs can be time consuming and expensive, so they are only added to ready to run units by special order. If you are looking for boards with a standard feature set, you can use a MicroSquirt or MS3-Pro. Sorry, the only official documentation for modifying an MS2 for boost control is on MSExtra.com. They are working on an overhaul. Right now, there's this schematic: http://www.msextra.com/doc/ms2extra/MS2-Extra_Hardware.htm#boost If this one is difficult to use, if you can specify what questions you would like answered that aren't answered there, I will do my best to answer them.

Correct, MegaLogViewer is a separate program. It is shareware, so you can try before you buy. TunerStudio is not able to play back data logs.

For the no boost issue - is the MAP sensor reading topping out at 100? Can you get a tooth log of the loss of RPM signal? That will give us more to go on.

You'll need to fix the sensor issue to get the cold starts dialed in.

Good call! Adding that now.

We don't have a model specific map, but following the initial settings / first start guide should get it up and running: http://www.msextra.com/doc/ms3/firststart.html

Thanks! Let me know if there's anything that it needs added.

We've had a couple people asking for a guide to tuning MegaSquirt's startup settings lately, so we've put one together on our site: http://www.diyautotune.com/tech_articles/megasquirt_startup_tuning.html Let me know if you have any questions about it!

Try reducing the cranking pulse width.

You're welcome. Glad to hear it's fixed!

Either that, or it's losing sync and pulsing the fuel pump LED off. Is the RPM dropping to 1 or 0 on the test?

Yes, the stuff wired to JS10 is for sequential.

1. With the O2 sensor disabled, I'm kind of flying blind on what the fueling is doing. Can you get a wideband on that ECU and log the fueling with it? 2. You're occasionally losing sync - can you get a tooth log of that? 3. Looks like the TPS either is not working or not calibrated. (Or are you using an on/off TPS?)

With 2.6 firmware, just ignore the ignition options. If you don't have it up and running yet, consider swapping to MS2/Extra 3.3.1 firmware - it's a bit easier to set up.

Ok, if that doesn't pan out, email me and I can get you the return paperwork.

You have the decel fuel amount set to 5%. This is a multiplier, so 100% is no fuel cut - try setting the decel fuel amount to 100% and see if that helps.