Matt Cramer

Either one can work - I've used "ground switched" mods with LSx coils before.

Injector staging wouldn't do this. It could be your cranking pulse width and/or ASE is a bit off - these are dialed in at different temperatures, so a change in the weather can suddenly keep the car from starting.

Were you getting an error message of some sort? If so, could you please post a screen shot of it?

250 to 255 is a typical maximum value for MS1; MS2 will go a lot higher. Just accept the values the screen gives you.

I'd adjust the VR trim pots in that case. Could be you're losing the signal.

Those values sound quite normal for an MS2. Are you having other problems with the TPS?

Some of the settings you mentioned aren't normally used with EDIS. Is this a crank triggered distributor setup? Could you post the MSQ (tune) file out of the unit?

In theory, you don't need to time EDIS, but in practice the trigger wheel installation may not be 100% accurate. It doesn't hurt to check.

I'm pretty sure it's mechanical at this point. The ECU is working, the coil is sparking, but the spark isn't getting through the distributor. I would suspect either your timing or the rotor phasing is off.

Check it with a timing light; where is your timing while cranking? It may help to have the injectors unplugged while checking timing. Then you need to get the cranking fuel dialed in. After an unsuccessful start, have a look at the plugs. See if they're wet and you're getting too much fuel, or dry and you don't have enough.

Ok. At this point, I'd check the rotor phasing and make sure that is OK. Also, any chance you may have internal damage to the distributor cap? I've seen some brand new distributor caps ground so off-center they'd probably break if put on an engine.

Bingo! I also took a closer look at your MSQ. There's a lot of weird settings in it besides the flood clear value. Did you by any chance just open MegaTune and start composing an MSQ before you connected to the Megasquirt or loaded a valid file? If so, MegaTune will default to a file full of zeros. If that's the case, I recommend reloading the firmware and starting with the default values - either edit them in the Megasquirt or save them and edit them offline.

Could yo post a data log of it cranking?

The rotor phasing could be the problem, so it wouldn't hurt to check. Also let me know what you find about the LED on the Stim. The blinks may only be visible at low RPM settings.

Does your Stim board have an IG LED? If so, does it blink when you test the MS on it?

MegaSquirt is seeing an RPM signal, right? Do the injector outputs work on a Stim?

If you could catch this problem in a data log, I'd be glad to look through the log and see if I can find any clues about what's going on. I'd also like to have a copy of the MSQ file along with the log. Let me know if you can get one.

MS will work without either an IAC or an O2 sensor. Tuning without O2 feedback is a pain... but even if you do have an AFR gauge, it doesn't need to talk to the MS for it to run.

Looks like you found the problem.

On V3.0 boards, it is an actual step, but on V3.57 boards, this jumper was removed. The center hole of Q16 goes straight to pin 36. These are not necessary steps, but do not hurt either. Pin 36 does not send out a voltage, but you can get a test light to blink if you use an LED type test light, connect the negative wire of the light to S5 or pin 36, and connect the positive end to a 12 volt source.

If you test the board on a Stimulator, does the IG LED pulse?

Try changing the jumpers to Hall/optical input - JP1 to 2-3, J1 to 1-2.

Ok, we'll need to get it working on the Stim first. Could you post your MSQ? I'd like to have a look at it.

Ok, I don't have a "correct" MSQ for your setup to compare things to, so I am not going to look through your MSQ, just go over how to get this fixed. First off, if it will start cold, great. Get it started, get it warmed up to operating temperature, then go to the VE table and get the idle dialed in. Decrease the numbers in the load cells when it's too rich. This may actually fix the hot start problem too. But if it doesn't, you'll need to go back and dial this in. Here's how to handle this one depending on the symptom. 1. Engine just cranks and floods, but doesn't catch - decrease cranking pulse width. 2. Engine cranks, catches a couple seconds, then dies - adjust after start enrichment. 3. Engine runs poorly while warming up, after about 20-30 seconds - adjust warm up enrichment.

Can you get RPM on a Stimulator?