PJnB

Ok here is the story:

I ordered a MSPNP for my 99 miata from Braineack. The goal was to megasquirt my stock motor with 440 cc RC injectors. The first step I took was obviously installing the injectors. They went in fairly painless. Car started no problem other than running a little rich with the new injectors. Next step was AEM Wideband. Everything with that install went fine.

Next installed the MSPNP. (This was all done with the battery disconnected) I installed a vac line running from an unused vac line connection on the back of the intake manifold to the megasquirt. Removed the stock ecu without any issues. Plugged up the MS into the stock wiring harness. Plugged in the wideband connection to the MS and connected the MS to my laptop. Reconnected the battery. Proceeded following the instructions given by Braineack to set up the firmware on the megasquirt. (NOTE: I did not install the GM IAT censor because I still have the stock airbox on the car and did not have a place to install the sensor.)

So the first issue that surfaced was that the TPS was not reading into the megasquirt. When I tried to calibrate in TunerStudio it read in the same throttle position (109) for no throttle and full throttle. SO I thought about what could be wrong. PM'd Braineack. Cracked the MS. Confirmed a few connections on the board for Braineack. Couldn't figure out what in the MS could be causing the problem. So I decided to just skip that step temporarily and return to it in order to see if the car would even start. So I put in the remaining calibrations required before the initial start-up in the instructions and then tried to turn the motor over. Nothing. Starter motor didn't turn over. No clicking. Absolutely nothing. Tried jumping the battery to start it. Still nothing. So next I decided to just disconnect the battery throw the stock ECU back in and try and start the car like before with just the injectors, just to make sure the MS was the problem. So I did this and the battery was dead. BUT with the stock ECU the starter was clicking.

So next I took the battery and got it FULLY charged instead of just jumping it. Plugged it up, got the MS put back in and everything hooked up and started all over. STILL no TPS readout. Tried to crank the motor again skipping the TPS. This time when I tried to crank the motor the starter kicked right in and cranked the motor BUT it didn't even TRY to start.

So after that I took out the MS. Put the stock O2 Sensor back in. Hooked up the stock ECU. Hooked up the stock battery and tried to start it. Same thing as with the charged battery with the MS. Just cranked. Didn't even try to start. ONLY thing not stock was the 440 cc injectors which I started the car before with no problem the day I installed them.

I guess my next thing I am going to try is pull all the coil packs and injectors and see if they spark. But if they all spark...I am totally clueless. I was thinking that I would send the MS back to Braineack to see if he can see anything weird with it but I don't really think that is the problem anymore. I don't know what I blew up in the process of taking out the stock ECU and installing the MS. Is there ANY common fuses that are at risk or ANYTHING anyone can think of? I would GREATLY appreciate any help. Thanks for reading!

Matt Cramer

Whoa. Back up. Whatever you have is not an MSPNP. We're a bit protective of this for a couple reasons - mostly because the MSPNP is a very specific hardware design with several circuits unique to it. So trying to use information for troubleshooting or setting up an MSPNP for a non-MSPNP often won't work. Second, we've had a case where somebody was dissatisfied with a MegaSquirt he bought from another vendor (not Braineack, he generally takes pretty good care of his customers) and was calling it an MSPNP - obviously, we didn't want that confused with us!

Braineack builds a couple different plug and play gadgets so this may be a DIYPNP or a regular MS of some sort with an adapter harness.

To troubleshoot this, first see if you're getting RPM while cranking in TunerStudio. Are you?

Ben

iTrader: (33)

Have you done anything to clean off your plugs? 440cc injectors on a stock computer = fouled plugs

You may have an easier time if you stick to stock injectors for now. When you get things running, then put in the large injectors.

PJnB

Matt, My bad. What I have is the DIYPNP MS2 that Braineack sells. And he has been extremely helpful so far but we are still having trouble figuring out what could be wrong. I have not looked at TunerStudio while cranking. I will give that a try and see what happens.

Ben, now that I think about it...I really should have put the MS in before the injectors. But I guess it's kind of too late for that now. Do you think I should put the stock injectors back in?

Matt Cramer

I would, at this point.

PJnB

If all else fails I will throw the stock injectors back in, but I want to see if anything else works first. One other quick question: does the stock ECU or the MS have to be grounded in any way by the bracket mounts? or can they just be dangling by the wiring harness with no other connection to the rest of the car?

EunosBen

Put back to stock
Get it running
Retry only changing ECU.
Proceed.