Ok, so here's the deal. I recently bought an 87 tII. It's ported and ran a Megasquirt V 3.0. Long story short, I knew that it was running super rich and it needed a tune, however, it didn't have a wideband O2 sensor. According to the MS software, the air intake temperature sensor was reading at 40 degrees less than what it should. on the forums, it says to replace the r4 resistor with a 33k-50k resistor. so we did. nothing happened. except now, i was getting no spark. Ive heard the MS is nothing but a hastle, so i reverted the T2 back to stock: old ecu, newish wiring harness from another 87 t2, maf, boost pressure sensor, fuel injection resistor pack, newish 550cc injecotrs, (if Im leaving anything out, lemme know). Anyways, I took out the MS and put everything back to stock. however, im still getting little to no spark. we changed coil packs 2 times, changed the ecu 2 times, put in new plugs, and replaced the crank angle sensor. does anyone have any other ideas? i am so lost right now!!!!

thanks a bunch

 

try changing the resitor back?? maybe there is a chance that the resistor is bad?

 

did the previous owner hack up the CAS wiring? it needs to be in good condition. Also check all your grounds.

 

Even though you changed the resistor, you still need to calibrate your sensors. It's in the MS rotary f.a.q. If you don't, it'll always read off.

MS is a pain to learn at first. The hardest part isn't tuning it. It's easier than any other ecu I've ever seen in this regards. The hard part is figuring out what software to download, what updates are needed, what files to move where, where to get said files from, how to calibrate the sensors, where to get the software to do it, etc. If you can finally get past all of this, it's an easy system to get running quite well.

When you say "newish" injectors, do you mean high impedance? If so, why are you using a resistor pack?

On a stock ecu, even a bad afm can result in no spark. I had that happen to me about 10 years ago and damn near destroyed my car in frustration while trying to figure it out.

 

So right now, we are in the process of doing continuity tests in the harness and checking all grounds. Its a little late to go back to MS because i pulled it all in frustrations and reverted the car back to stock. but that doesnt mean i cant go back to it later. i probably will eventually, that or ill sack up and get a haltec. as far as the injectors are concerned, theyre used low impedence 550cc. tomorrow, i should know what the deal is. im sure its something stupidly simple. always is....

thanks for the support and the posts! ill let you all know what happens!

 

maybe the plugs were getting doused with fuel and then getting fouled? might be a good idea to check that out just to narrow down the possibilities for the failure. i was browsing around the Mazda 6 forums a few weeks ago and people were bitching about how easy rotaries are to flood. generally, they were saying some pretty ignorant ****, and most of them sounded pretty clueless, but there might be some truth there. i know i fouled a few plugs when tuning.

the other thing i have heard is that you should disconnect your trailing plugs to take them out of the equation until you fix the problem. i have never tried this method though, as my engine has a trailing plug delete kit on it.
good luck.

 

Ok, so how much are you selling your ms unit for?

 

shoot me an offer in a pm