Dynotune appointment in two days and the car refuses to start, what luck :)
 

Hello, I need some help diagnosing an issue in my 1997 Miata with a MS1 PNP that was later converted to MS2 by the previous owner. I have a dynotune appointment on thursday and of course my car starts to not start now.

So what happend was my tuner wanted to know if my megasquirt would be able to run boost control. So he asked me to open the case and take a picture of the board. So I did that, closed it back up, and plugged it back into the car, including the vacuum line to the megasquirt.

I turn on the car and it had a crazy lumpy idle. I shut it off after a few moments of running. I do it 2 more times with no change. The car now cranks, it barely fires up for a few rotations then dies.

There is gas in the tank, fuel pump works, I smell fuel in the exhaust. For some reason the car doesn't turn over.

Anywhere that I should start looking?

Thanks in advance

Do you have spark?

I'm guessing no spark since I smell fuel in the exhaust.

This probably is a dumb question (bear with me, i'm an electrical+megasquirt noob), but how would I check to ensure i'm not getting spark? I have Toyota COP's if it matters.

Pull a spark plug. Put it in the coil. Ground the threads on the engine and see if it sparks.

Repeat for the other 3.

I'll have a crack at that tmrw since it's late. Don't want to piss off the neighbors. But depending on if there is or isn't spark, any advice on where to look after that?

I believe I found the problem. I pushed too hard with the vacuum hose and broke a few solders... stupid me haha. I resoldered them and the engine cranks over smooth like how it did before but still dies. I'm assuming the engine is just flooded, so I'll try again tmrw... time to sleep :sleep:

yeah I was about to say are you SURE you plugged the vacuum line back in... sounded like it was fueling for 100kPa.

I let the engine sit for around half an hour with the spark plugs out and fuel system fuse pulled. Also cranked it from time to time to let the fuel escape.

At the same time I checked for spark by grounding the sparkplugs on the intake manifold. I didn't see any spark. Any suggestions on where to look now?

Can you make it spark in output test mode?

Yes it is sparking in output test mode

now see if the cas is actually putting out a signal with a composite log

I tried to do the composite test but before I got a chance to do so, I got an error saying "Staged injection can only be used with simultaneous".

But if it matters, when cranking it before, the tach on the tuner studio interface matched the tach in the car.

I attempted a composite log, the black graph is empty and the white area on the left says "Empty Read, no data received from controller"

Is there supposed to be a wire connecting two pins in the diagnostic port in the engine bay? I opened up my diagnostic port and found a wire that seems like it was used to connect two pins together, but it was just sitting there not doing anything.

It very well could be for your fuel pump. But the fuel pump should be controlled by your MS.

I can smell excess fuel from previous attempts and I can hear the fuel pump running, so probably not. But I'm wondering if it could be for something ignition related.

The only thing ignition related would be setting the timing to 10 degrees with a stock ecu.

what two pins? lol.