Megasquirt owners thread

[maniac]

The car is a 1993 NA8 with an AVO turbo kit.

I have a decent understanding of what I need to do, but I'm slowly starting to get over it. I will try running the fuel pump off 12v to troubleshoot it.

It just wont tick over. Think its not getting fuel, but not sure why. Thinking it may be a wiring issue.

I'm getting sick of fiddling with it and just want to take it somewhere to have it done

Adam

I know I'm late to the party, but it would help to know what model MX5 you are trying to get this to work on. The early NA6 cars had wiring that requires the ST IGN fuse to be removed and the MegaSquirt wired to power 12V directly to the fuel pump. This is the normal way any MS2 or MS3 should be configured to handle this and common approach is to either run a 12V relay off the ecu fuel pump output pin, or to build a circuit with a FET or similar to drive the pump.

This question should also be directed to the person who built the MS3 board and to confirm what they were planning to ensure the board is suitable for an MX5 of your year and model.

I know this sounds complex, but this is why the MegaSquirt is available in a complete ready to run version (MS3Pro and MSPNP2) for those that don't wish to be mucking around, and a range of DIY kits (DIYPNP/MS2/MS3) for those that understand the electronics, build process and time to get it right.

If you're in the former category and you've got one of the later DIY kits then a mistake has been made (and it will probably cost you more than the difference to fix).

G

[gslender]

The car is a 1993 NA8 with an AVO turbo kit.

Ok, if it is indeed a stock harness for a 1.8 then you should be able to GND connector 4T with the ignition on and the fuel pump should switch on. If not, there is something else wrong (or it isn't a 1.8 harness etc) - the MS3 should be wired so that the ECU pin FP (for fuel pump) is wired to connector 4T on the harness. When the ECU is switched on the FP will go to GND for a few seconds before switching off (prime the pump before start). Once cranking is seen by the ECU it will start the pump again (GND) and fuel will continue to squirt and run etc..

Note: my previous advice for a < 93 engine 1.6 is not relevant here for 1.8 engines.

G

[Si.G]

Hi everyone, I have a new probably with my car and my MS set up

Mazda MX5 NA6 turbo
MSpnp2 MSExtra 3.2.1
Running Toyota COPs, wired into the factory harness. part 90080-02238

I am at the dyno tuning my car and all is well for about 2 hours. I have done my tuning up to 5000rpm and I am now ready for WOT runs. So far no issues. I do a couple of WOT runs, no probs. Next run, I start to get miss fires while the dyno is hold 2000rpm before starting the WOT run. I try again, same result.

I changed my plugs to from NGK iridium to the NGK SE plugs both in heat range 7. I gap the new plugs to 0.6mm. No change, still have miss fires.

I check the dwell and it is 4ms, this is too high for the COPs, should be in the 2.1-2.5 range I believe - this is my fault, I must of re-load the base tune I got and forgot to change it. So now I think, obvious, I have damaged the COPs

I drive home and the issue gradually gets worse.

Following day, I swap all 4 COPs for new ones. I go for drive and the probably still exists.

I have continuity tested my COP wiring, including negative testing all other terminals to ensure that none of the wires are touching others anywhere

Here is the msq and a log, you can see from the rpm that the engine is no pulling cleanly.
https://dl.dropboxusercontent.com/u/107850668/MegaSquirt/2013-11-06_19.24.29.msl
https://dl.dropboxusercontent.com/u/107850668/MegaSquirt/CurrentTune.msq

Note the AFR table might look a bit strange, because my innovate LC-1 is 1.0 AFR different to the reading at the dyno, so I changed it in an attempt to use auto tune, but I abandoned that. Also the VE and spark maps are not 100% finished, but I don't think that is part of the issue?

Any help in diagnosing is greatly appreciated, I have a dyno booked for Saturday and a motorsport event I have entered on sunday.

[gslender]

Any help in diagnosing is greatly appreciated, I have a dyno booked for Saturday and a motorsport event I have entered on sunday.

That particular version of MS2 firmware 3.2.1 is well known to have that exact problem - first of all, upgrade to the current supported release 3.2.5

If that doesn't solve the problem then I'd be checking the log for sync errors and if none exist, it must be outside the ecu (so something with fuel, spark etc).

G

[Si.G]

Any help in diagnosing is greatly appreciated, I have a dyno booked for Saturday and a motorsport event I have entered on sunday.

That particular version of MS2 firmware 3.2.1 is well known to have that exact problem - first of all, upgrade to the current supported release 3.2.5

If that doesn't solve the problem then I'd be checking the log for sync errors and if none exist, it must be outside the ecu (so something with fuel, spark etc).

G

I cannot believe it, the firm ware upgrade has sorted it. Well, I totally believed what you said, but just knowing the journey I have traveled it just seemed everything was stacked against me and my luck was out.

We are super lucky to have good people like you on the forum.

Any idea what happened. I was happily tuning and then next minute issues. I am guess i must of hit some sort of boundary condition/defect in the firmware code? Being a developer, maybe I should take a look at the code one day since it isn't assembler anymore

Thanks Again - Si

[gslender]

That issue is in the interrupt assembler code of the timing wheel and I think is only an issue when using sequential injection. It doesn't present itself when running batch and is why so few people know about it.

G

[gslender]

Server issue double post

[gslender]

Those running Megasquirt 2, you may wish to more closely follow the following new firmware release of the msextra forum.

MS2/Extra pre-3.3 release candidate 1

There are a bunch of new features added to this 3.3 release above that of 3.2 (things like MS3 style tuning screens, the AC idle up code I wrote and many ms3 features back ported into the MS2).

As it is now nearing a release candidate, the code and quality of release is high.

Cheers,
G

[david_syd_au]

I ordered a MS2PNP and wideband yesterday, destined for my NB8A track car.
Thanks gslender for your advice.
Let the adventure begin! :-)

[thelaughingman]

Hello Gents,

This is my first aftermarket ECU that i'll be attempting to play around with so with that here is my soon to be setup
- MSPNP MM9495
- LC1 Wideband

Now bare with me as this is going to get tricky...

Would anyone know what i would need to get this to work on a 1990 1.6. Im aware that this isn't for a 1.6, rather its for a 1.8 but i dont see why it wouldn't work.
Any ideas are welcomed (please dont say just get a xxxx unit for your car as the unit i just organised was cheap )

[gslender]

Hello Gents,

This is my first aftermarket ECU that i'll be attempting to play around with so with that here is my soon to be setup
- MSPNP MM9495
- LC1 Wideband

Now bare with me as this is going to get tricky...

Would anyone know what i would need to get this to work on a 1990 1.6. Im aware that this isn't for a 1.6, rather its for a 1.8 but i dont see why it wouldn't work.
Any ideas are welcomed (please dont say just get a xxxx unit for your car as the unit i just organised was cheap )

It is wired differently for a start.

G

[thelaughingman]

It is wired differently for a start.

G

I just had a response from DIYAutoTune:

A few things where changed from 90-93 and 94-95 on the Miata. The system its self should be able to control both engines, although some repining would be required. I have included two links below from out DIYPNP install article. On each page, we have pin out information for the factory harness. You can use this to find the required changes to match the pin out of the 94-95 ECU.

http://www.diyautotune.com/diypnp/apps/ ... b6-mt.html
http://www.diyautotune.com/diypnp/apps/ ... bp-mt.html

My response:

Thank you for your quick response.

So just o confirm, provided that I re-pin my harness to suit the 9495 ECU I should be able to load on a base map and go from there?

2nd Reply from DIY:

The ECU demands are just about the same for miatas from 90-97. Although the harness pins did change almost every other year. If you are able to successfully repin your harness for the 94-95 ECU, the system should work. This falls outside of the "Plug and Play" aspect of the MSPNP, and something we may not support. I have provided the required information should you decide to make the changes.

Looks like I have my answer

[bigmaxy]

Make sure you document what you change for when you sell it to me. Lol. Good luck though, hope it works out.

[thelaughingman]

Make sure you document what you change for when you sell it to me. Lol. Good luck though, hope it works out.

I'll do you a deal get me the right mega squirt and i'll trade you haha

[Mr nanotech]

Not sure what to do and need some advice.

I had my car previously tuned to run 550cc injectors and had a 9psi superchager setup. Long story short I'm tuning the car for n/a again. I have a 1990 B6 NA and am using DIYPNP2 ecu and an Innovate LC-1 wideband sensor and a GM IAT.
I had a problem with the wideband turning off after approximately 20mins of driving. Since the car had been run very rich before and now in n/a state with the big injectors still in, I expected some over fueling. I attributed the sensor failing to the car running too rich and coating the sensor in black crap.

Today I pulled the wideband out and sure enough it was absolutely filthy. I read up on safe ways to clean it and saw the safest was to use brake cleaner and a clean cloth. So off I went and cleaned the sensor. Since I was already getting dirty in the engine bay, I decided to kill two birds with the one stone. Out came the 550cc injectors and in went the oem ones.
The plan at this stage was to run the car on a stock basemap and set it up for no AFM and run it on MAP as there will be no TPS in place.

I plugged in my lap top and started setting up my tune etc. When I started the car, the engine turned over as normal but did not start. It endlessly turns over and when it finally does kick, it coughs and splutters before backfiring and dying again.

Now since the car was running before my mind goes to two things. The first is that the wideband may not be functioning but as both tuner studio and my AFR gauge are getting a signal, this is highly unlikely. The second thought was that the injectors may be blocked or leaking. I don't smell fuel but I'm assuming that the car is being starved for some reason. It's come to my attention while typing that I have not changed the required fuel in the tune yet and maybe the car is asking for a higher fuel than the injectors can deliver?

Thoughts would be great. I'm dying to drive it.