Si.G's NA6

[Si.G]

The inj circuit in the ecu is simple a Gnd, so you should be able to trace the problem with a DMM. Remove the ecu and power on the ignition, see what you've got on the inj wires at the connector, and then test the resistance, it should also be the same on both inj (around 12 ohms).

Also, what's "blowing" on the DIYPNP? The injector drivers are on the microsquirt module... Or are you running Sequential, in which case 3 /4 are on a little module.

Finally, you can even run the ms2 in test mode with only 1 inj wired up (bit of a pain to do, but worth making a makeshift inj plug with alligator clips etc) and test each injector individually with the ms2

I have checked the wiring, but just grounding the wires at the connector - all injectors click, I did not test the resistance, I will definitely to that. I have a MSPNP2, so I think it has additional injector driver circuits because it can run sequential. I am waiting for diyautotune to let me know what exactly happened, because I can't keep sending it back and then breaking it again.

I did check the resistance across each injector and it was around 13ohms from memory.

Good idea on testing each injector individually. It is only one of the drivers that is blowing, so if I do have to send it back to diyautotune, I might be able to use the working driver circuit to help me diagnose the issue.

Thanks for the reply, very very very much appreciated

Si.

[Si.G]

(edit above, great English/typing

I have checked the wiring, by just grounding the wires at the connector - all injectors click, I did not test the resistance, I will definitely do that. I have a MSPNP2, so I think it has additional injector driver circuits because it can run sequential. I am waiting for diyautotune to let me know what exactly happened, because I can't keep sending it back and then breaking it again.)


rechecked the injectors, each is 13.0 ohms.

I tested the resistance at the injector harness connector in the engine bay and got 6.8 ohms for each bank, which is about right really given that there are 2 injectors in parallel.

The harness to the ecu has been continuity tested, and as I said before grounding the ecu pins clicks the injectors.

I have tested each injector with a 9v battery also.
I tested the injector harness off the car too and it worked (with 9v battery)

unfortunately I am going to be away for a few weeks, so will not be able to do much more for a while, I will possibly send my ecu back to be fixed, but I really need to get to root cause before I plug it back in.

[Si.G]

Half an afternoon to build an injector loom to fix this.
Dann

if I go sequential do you think 1000cc will be enough on E85?

[gslender]

(edit above, great English/typing

I have checked the wiring, by just grounding the wires at the connector - all injectors click, I did not test the resistance, I will definitely do that. I have a MSPNP2, so I think it has additional injector driver circuits because it can run sequential. I am waiting for diyautotune to let me know what exactly happened, because I can't keep sending it back and then breaking it again.)


rechecked the injectors, each is 13.0 ohms.

I tested the resistance at the injector harness connector in the engine bay and got 6.8 ohms for each bank, which is about right really given that there are 2 injectors in parallel.

The harness to the ecu has been continuity tested, and as I said before grounding the ecu pins clicks the injectors.

I have tested each injector with a 9v battery also.
I tested the injector harness off the car too and it worked (with 9v battery)

unfortunately I am going to be away for a few weeks, so will not be able to do much more for a while, I will possibly send my ecu back to be fixed, but I really need to get to root cause before I plug it back in.

Mmmm, that would tend to suggest there is nothing at all wrong with the harness or injectors.

I'm now a little confused because I think you have a NA6 and this would mean your stock harness isn't wired for sequential and that you'd be running it as Batch Inj - so you'd be unable to run those 2 extra inj drivers in the mspnp2 - this would also mean you need to ensure the config is setup for "Untimed Injection / standard drivers" so that the batch fire on the 2 injectors in the stock Denso connector are firing correctly.

How did you know it "blew" the injector drivers - did smoke leak out? Did it just fail to start, or something else? The injector drivers themselves are fairly bullet proof and you'd have to GND 12V continuously through them to blow them up.... so if the injectors are showing resistance and indeed the harness/stock connectors are all good, then there is no reason for the ecu to become damaged... so all very odd.

I'd be happy to help troubleshoot, but need lots more info on what exactly occurred - email me on gslender @ gmail dot come if you wish to explore further.

G

[Si.G]

The mspnp2 comes wired for 4 injectors, 2 circuits are wired into unused pins. I would have to re wire my car to go sequential.Was thinking of going sequential to remove wiring as the cause.

Currently running the stock 2 injector circuits, on the stock harness, sorry for the confusion.

How do I know there is an issue - injector bank 2 does not fire in the test mode at all, no clicking bank 1 works in test mode.

I agree, I think the wiring is sound from all the testing I have done, plus I have not changed the wiring. Only thing it could have been is a broken wire, but the wiring all checks out ok.

I also changed from 305cc injectors to 550cc, could an injector cause the issue?

[gslender]

Ok. So is the mspnp2 definitely for the NA6 as the later models wired the injectors on completely different pins on the connectors. Ie if you do wanna go full sequential you need to wire down to the db15 to easily connect up the 4 drivers to the injectors.

I'd swap the injectors from bank to bank to rule out a bad injector. Just because it isn't clicking when tested wouldn't make me assume anything is damaged. The driver circuits are fairly robust and you'd have to have really bad wiring fault to damage them.

Finally, if you want to send the ecu to me I have a test harness and simulator for the na6 that I can use to confirm if indeed the kit is broken. Happy to have a look at it if you're willing to post round trip.

G

[Okibi]

. if you want to send the ecu to me I have a test harness ..

Such an awesome offer

[Si.G]

The mspnp2 comes wired for sequential at the db15 connector, it uses what would be pins 2X and 2Z from this diagram

http://www.miata.net/garage/ECU_Pin-Out.png

I did some more testing this morning based on an email from diyautotune, everything seemed to check out ok. Involved checking voltage at the transistor and jumping a 5v supply over to jumper pin which made the injectors click - unfortunately I am not so hot at anything more than basic electronics, so I have no idea what I tested

I think I will have to leave it now until I get back from the uk

[gslender]

The mspnp2 comes wired for sequential at the db15 connector, it uses what would be pins 2X and 2Z from this diagram

That doesn't make sense. 2U and 2V are the stock pins for the batch injector wiring for injectors 1/3 and 2/4 respectively. Pin 2X has nothing to do with injectors on any model MX5. Pins 2Y and 2Z are the commonly used ecu pinouts on the later model for 3 and 4 injectors (with 2U and 2V being injectors 1 and 2).

I've sold heaps of MSpnp Gen2 kits and I'm familiar with how it comes (assuming you've bought the model for the 90-93 NA6) - if you want sequential you really need to build a new harness for the injectors and wire it to the DB15 and just ignore the stock connector and harness.

I did some more testing this morning based on an email from diyautotune, everything seemed to check out ok. Involved checking voltage at the transistor and jumping a 5v supply over to jumper pin which made the injectors click - unfortunately I am not so hot at anything more than basic electronics, so I have no idea what I tested

The ecu's CPU has input and outputs that all work at 5V TTL and by simulating a 5V load in the switching mosfet (injector driver) you are doing what would normally occur by the CPU to confirm that the mosfet chip is working (or not). If this clicked it means the electronics on the main board are working. If it doesn't work with the ECU then it is also likely a configuration error on the ECU (which can be fixed by ensuring the right tune is loaded) or there is something really rare wrong with the CPU.

I'd be thinking the tune could be culprit here and if you send me the tune, I can confirm or at least check to see what it might be.

Also, is the project file in TunerStudio setup for Microsquirt/DIYPNP ?? - you can't use the MegaSquirt 2 tune and configs as the DIYPNP and MSPNP2 both use the Microsquirt module and they have different pins and outputs on the CPU - which could be the problem!!

G

[Si.G]

this is off the ms pnp web site http://www.megasquirtpnp.com/docs/mspnp_g2_mm9093.htm

Sequential Injection
The MSPNP-MM9093 is capable of sequential injection. '93 California models are already set up for this; all others must have their wiring harness repinned at the ECU to use this feature. You will need to wire up the injectors using this pinout for '90-'92 and '93 Federal models.

Cylinder ECU pin
1 2U
2 2V
3 2Y
4 2Z

To enable sequential injection, go to the Advance menu, select Sequential Injection, and set Sequential Injection to "Sequential / Semi-Sequential." Click Burn, and turn the MSPNP off and back on again.

Does not matter anyway



Quite funny really. The ECU is fixed, but why did I think it was still broken....

Because after the fun of swapping injectors out previous and getting fuel everywhere, I decided not to hook the fuel lines back up and to leave the pump relay un-plugged, with a plan of using the test output settings in tunerstudio to test the ecu. I tested bank 1 and 2 in tunerstudio and got nothing on bank 2, hence the last few posts.

In an email conversation with Matt from diyautotune, he mentioned in passing ... "The second bank is actually bank C on these cars". I had a light bulb moment cycling to work. I had not even noticed that second combo box for testing injector banks 3 and 4 in tuner studio, because I had been focused on the fact that I have 2 banks of injectors only. I test bank 3 and click, click, click. So the injectors are wired into circuits 1 and 3 of the 4 available.

I hook the fuel up and it starts first time

Sorry for confusion and I very much appreciate you getting involved Grant and chipping in.

I have gotten a tune for an NA6 with 460cc injectors from the diyautotune web site, I have tweeked the required fuel settings and the other setting for my cops etc, it runs pretty sweet. Obviously still needs a full tune. Sad thing is, this has been so long coming and I can't do anything for 3 weeks
Si.

[Okibi]

Great news Si!

Let us know if you wanna do a run to give it a tune.

[Si.G]

Finally got the car back in to a driveable state today. There still many loose ends to sort though, as you can see



New catch can, tidy up wiring .....

I have been out driving / tuning today - started with a map from diyautotune from a B6 turbo running 430cc injections, it is pretty close after some minor adjustments. I have been taking things very easy at the moment and staying away from boost as much as possible, I just want to get some Kms on the car. No issues so far though (touch wood). It is very tempting to get the boost going for the choo choo !!! I have not fitted the boost controller yet either, so I think the actuator is 10psi - not that I have been anywhere near that.

I have also started talking to an engineer. I have decided that driving around with a dark cloud over you, hoping that nothing bad happens is not good. The initial conversation sounds promising and that it will not be too hard, but time will tell. Hopefully will be going to visit the engineer soon. There will be small things to do like, put the wind screen washer bottle back and in, change my harness for one with a compliant buckle, stuff like that. Plus one more major thing, which is get bigger brakes, probably going to get wilwoods.

Once I have some more kms on it, it is then off to the dyno

Si.

[Okibi]

Great news Si !

Looking forward to seeing you getting some choo choo soon.

Will you be at Barbs tomorrow?

I don't know if Wilwoods are ADR compliant.

[Si.G]

Fitted the boost control solenoid today and wired it up.



i have been doing a bit more tuning, but to be honest it is difficult to do on the local roads. I just want to get the fuel table a little bit closer in the lower regions before going to the dyno. I need to do a little bit more work to make sure the boost controller is working correctly, but then I think i am going to have to go to the dyno and spend time at the dyno dialing in the boost control and the knock sensitivity.

Hopefully I will get to the dyno in the next 2 weeks ready for the next club event.
Si.

[NitroDann]

You need to dial in boost control on the road.

You want the car to feel right in terms of throttle pedal input torque output, and you can only do that on the road to suit your tastes.

Dann