Bought a Miata that won't start - Help Troubleshoot
 

Hi all,

I found a good deal on a 1990 Miata that was already turboed. The problem? The car cranks but does not fire.

The previous owner says the car ran fine and then one day it just stopped.

He thinks that there was a bad ground on the MSPNP and he thinks it shorted something. He also said when you plug the MSPNP ECU in, the fuel pump continuously runs, I haven't tested it yet since I just got it.

VID_20130713_155601_zps5b5cb548.mp4 Video by HardHitter2k4 | Photobucket

The link above will take you to a video of my attempting to start the car. I connected the battery, connected the stock ECU and you see the results. I was told that the ECU needs to be grounded though, so I need to try that as well.

Any idea on where to start troubleshooting/checking?

This is what the bay looks like currently and yes I know the wastegate isn't connected.

https://www.miataturbo.net/attachmen...ine=1373820329
https://www.miataturbo.net/attachmen...ine=1373820329

Did a little work on the car just now.

Hooked up the MSPNP and tried to start the car. As usual, turned but didn't fire. Turned the car off and could hear the fuel pump or what seemed like the injectors still firing or something under the hood. Went to the battery and unplugged it. I noticed the MSPNP was lite up so I'm pretty sure it's getting power. Don't quite know what the sound was even after I stopped trying to fire it up.

After I pulled the battery, I went to the front of the car and pulled the valve cover. I didn't need to do this, but I wanted to check the condition of the timing belt.

Here's a few observations I checked along the way:

1. When I pulled the spark plugs, they didn't seem "wet" with fuel. What exactly are they supposed to look like when they are wet? Here are pictures of the plugs after I tried to fire the motor

https://www.miataturbo.net/attachmen...ine=1373830562
https://www.miataturbo.net/attachmen...ine=1373830562
https://www.miataturbo.net/attachmen...ine=1373830562
https://www.miataturbo.net/attachmen...ine=1373830562

2. Once I pulled the timing cover off, I inspected the timing belt. Checked the flex and underside of the belt itself and it looked actually brand new. Don't think it's my timing belt that is the problem. I guess one question I did have, would it be safe to hook the battery up and crank the motor to ensure the belt is good all the way around? I could also check to make sure the valve train is well. Here is a video of everything:

VID_20130714_115130_zpsc0d57fd1.mp4 Video by HardHitter2k4 | Photobucket

Have you hooked your laptop up to the ECU yet? Connecting the the ECU and reviewing the gauges/inputs would be my first task.

But, during cranking confirm the status on all these: spark, fuel, fuel pump running.


From your video I DONT hear the fuel pump priming/running, if that's the case what I'd do is go into the diagnostics box, jump F/P and GND, try starting it again and enjoy a running car. If you ST_SIGN fuse is not removed, there's a good chance the MS is not controlling the fuel pump, or there should be a jumper in the AFM connector where the AIT sensor should also be connected to...depends on how the unit was built.

But also form you video I don't see the tach moving, which means the MS is not getting the signal from the CAS, which means you're not injecting fuel or sparking plugs. You'll need to connect to your laptop with Tuner Studio, click the Diagnostics tab, check save to file, and click start. Crank for a good 20-30seconds and then click stop. Upload the CSV file you created. Then we can see if your MS is actually reading the CAS and if not, which signal is not reading if any or both and we can go from there to fix your unit. I'd also post your MSQ and upload a regular datalog during cranking (datalogging > start logging)

One more thing, if you can't connect to the MS with your lap, disconnect the TPS connector and try starting the car and/or connecting again. The unit could have been built for a vTPS and with the factory TPS connected this will cause a short to ground and the car wont run in this manner.


I hope you got a good deal, as I can have this thing running again in about 5-10minutes.

@Braineack

I took a better video to show you what I'm talking about. Previously the video was with the stock ECU.


This time, the video is with the MSPNP hooked up and the F/P and Ground connected by a wire in the diagnostics box. You will note a few things on this video as you watch:

1. The MSPNP light that I originally said comes up isn't on when I try to start the car but DID come on AFTER I turned the key to off
2. The sound of what I think is the fuel injectors still shooting happened AFTER I turned the key to off and removed the key @ the 1:00 mark which is why I ran out the car to the engine bay again. You can CLEARLY hear some type of ticking.
3. @ the 1:30 mark, you can see the MSPNP light up but only the very bottom of the first P. Maybe there is a short with the MSPNP and it is the problem?

I wasn't able to hook the MSPNP up to my laptop cause I didn't have a serial port (fail) I have to go buy a serial to USB converted on Friday when I have it off.

you probably need a new CAS, but the injectors cycling like that at rest is weird; you really need to connect to the MSPNP and review the tune.

Thanks Braineack

I just ordered a serial to USB converted from the site so I'm hoping it gets here by Friday.

I'd be extremely happy if it is just the CAS.

It could potentially be the fueling because I've been told when you crank the motor your injectors should be wet. The pictures I have of the injectors above are after I was trying to fire the car.

To me they all look dry except the first picture of the plug. I see a slight change in color tone.

injectors or plugs?

Sorry, I was thinking fuel and thought injectors. The plugs should be wet according to this post:

"Also, while plugs are removed, visually inspect them for damage, excessive buildup, oil in the plug wells, or other obvious issues. Check to see if they are wet- if not, fuel is not reaching the cylinders."

that's a retarded way to check for fuel.

a non-retarded way is to actaully disconnect a fuel injector and see if its firing.

or better yet, before you do any more blind testing, actually hook up to the ms and figure out what is even in there, then if everything is alright start logging and composite logging to see if you're getting signals from the cas or the issue is something else

Yea I'm waiting for the serial to usb converter comes in so I can hook it up.

A think I noticed is that my CEL doesn't show up when attempting to fire

"2)Step 2: Cranks but will not fire- this scenario is a bit more complex, but manageable.
a)When the key is turned to “RUN,” does the Check Engine light come on?
i)If YES: Pull stored fault codes from ECU and refer to the article to decipher them. I would recommend doing this twice- pull the codes, clear the codes by temporarily disconnecting the battery, try to start it, and then pull the codes again. This will be particularly useful if there are a lot of old codes sitting in the computer’s memory.
ii)If NO: The ECU is not firing the Check Engine Light. This means that power is not reaching the ECU, power is not reaching the Check Engine Light or the computer is bad. "

now im cross posting:


If you want this solved stay here; it's an ECU issue with a possible failed CAS. If you had the stock ECU and AFM, im willing to bet the car would start and run.

The MS needs to first read the signals from the CAS, sync, then it will fire the coils and inject fuel according to the loaded tune's parameters. So if the CAS is failed, or the MS is looking for a different pattern, it will never fire the coils or injectors.

I have the stock ECU, however it didn't came with the stock AFM so I'm out of luck there in troubleshooting unless I can find someone local.

I'm going to wait until I can plug the ECU into my computer and we can go from there. I'm hoping it is as simple as the CAS.

it might run, in the least catch, without the AFM--you'll just have to jump F/P and GND with a wire in the diagnostics box when doing so.

Worth a shot to rule out the CAS or not.

I'll try the stock tonight when I get home from work. Someone told me that I need to ground the stock ECU?

it's grounded when you plug it in. stop talking to this person.

Haha thanks I'll try it out tonight.

So I actually got to the car before I left for work.

I plugged the stock ECU in. Had a paperclip going from GND to F/P. Turned the car to the 'On' position and I could hear the fuel pump going. Tried to start the car and still didn't start. On the dash the only lights that lit up were the 'Charge' and whatever the one is to the right of it on a 1990, I think it was the 'Brake' one. No CEL lit up at all just like when the MS was plugged in.

After the car didn't fire, I took out the key, yet still heard the FP (or so I think it is the FP) running until I disconnect the battery.

Shoot me a PM if you end up needingn a new CAS. I am pretty sure I have one just chilling on my garage floor.

Damn, I sent a guy $20 for a 1.6L CAS. A few seconds too late on my part haha. Thank you for the offer!

good chance the CAS really is bad then.

the F/P to GND activates the pump constantly with key ON; this was necessary without the AFM as the flapper being sucked in with vacuum is actually what keeps the fuel pump relay turned on after cranking.

There shouldn't have been power still going to it with the key out, that suggests some tom-foolery in the wiring, as the fuel pump relay is powered off the main relay, which is triggered by the ignition switch.

Update on my status:

Tried to connect the MS to laptop and nothing was identified

- F/P and GND are jumped
- USB port is showing up in device manager (USB Serial Port COM4)
- Connected Battery
- Turned key to start position and tried to detect the MS to not success

Video of how the MS is hooked up:

Video of me trying to detect the MS:

After I turn the key to off and remove it, the same situation happens where I hear the click and seems like the fuel pump still on.

Wait, you get no cel with the key on and the stock ecu plugged in? Either its burnt out of the ecu isnt getting power/ground.

Right, I've tried starting the car with both the stock ECU and the MS and both videos don't show a CEL light.

Trying to start the car with stock ECU:
VID_20130713_155601_zps5b5cb548.mp4 Video by HardHitter2k4 | Photobucket

Trying to start the car with MSPNP:

Took a quick video of the type of wiring I'm dealing with here...grounds leading to grounds?

You laugh, dont ever take apart a factory harness. I swear it was designed by 6 engineers that hated each other.

I feel that wiring is going to be an issue. I spy a push start, and although that is simple to do, people don't always do things the easy way. So what else in the harness has been messed with? This looks like a fun project (I'm serious), good luck :D

run through this: Megasquirt Serial Setup

your MSI should be 9600 baud rate. It's possible the firmware is bad on the MS...Don't go hacking through wiring quite yet; lets get the ECU connected and see what's going on...it's a useful tool.

Thank you Braineakck, I'll troubleshoot this evening and get back to everyone.

So let's get a little troubleshooting update. Some good progress I think but also strange...

I followed the instructions documented on the MS Serial Setup (Megasquirt Serial Setup)

Device Manager shows that my USB-Serial is showing up:

https://www.miataturbo.net/attachmen...ine=1374204186

I then connected it to the MS and turned the key to "Start". Ran the 'Portcheck.exe' program and nothing was identified:

https://www.miataturbo.net/attachmen...ine=1374204186

I then tried to start the car and of course it didn't fire. Removed the key and then saw the MS light up with the usual "clicking". Decided to execute the Portcheck again:

https://www.miataturbo.net/attachmen...ine=1374204186

Quickly opened up TS and opened a new project and hit 'Detect' and it actually found the MS:

https://www.miataturbo.net/attachmen...ine=1374204186

Tried to move forward and then ran into this problem and didn't know what to do from here:

https://www.miataturbo.net/attachmen...ine=1374204186

you need to reflash the firmware.

MegaSquirtPNP by DIYAutoTune.com

go there. grab the .exe file and the MSPNP_MM9093_Base_Map_112807 - no AFM.msq.

Run the .exe to install megatune (even though you won't use it).


now, it's been a REALLLLLLLY long time since I flashed a MSI so i cant quite remember the procedure at this point.

You absolutely MUST unplug the ignitor or else you'll fry it up. and it's even possible you'll have to open the MS case and install a boot jumper in order to perform the flash, and you can't touch anything on the computer while it's flashing, else it will flash.

I suggest you email websales@diyautotune.com for the correct procedure on flashing the unit. Once you reload the firmware, connect with TS, and load that basemap .msq you grabbed above, come back and we can go from there. Until then, the car will NEVER start on the MS ECU.

it's still possible the CAS is dead as well that tach should be moving during cranking when on the stock ECU, I'm pretty sure one of your videos with the OEM ECU showed a limp tach as well? Can you confirm the tach does not show RPMs during cranking when the stock ECU is plugged in?

Right, I went about trying to flash the ECU with these directions (Megasquirt MS2/Extra Loading firmware and Upgrade Notes) but with no success. I tried to confirm I had connection to the MS, but it didn't show up. So when I run it, it comes back saying that there was no connection to the MS and so nothing could be flashed. That's why I'm thinking it is a wiring issue because of the inconsistency of it being able to connect to the MS.

In regards to the tach, in both using the MS and the stock ECU, the tach does not move

This is with the stock ECU: VID_20130713_155601_zps5b5cb548.mp4 Video by HardHitter2k4 | Photobucket

You can see the CEL doesn't show and you can see that the tach doesn't move when the car turns. I don't believe I tried it with GND and F/P in the diagnostics box

a boot jumper must be used on your MS when flashing.

Next time you have the stock ECU in, pull a spark plug wire and confirm spark when cranking. IF spark CAS = good. if no spark CAS = bad.

I still reject the wiring issue idea right now. Some basic things we gotta confirm first.

Ok, I likely don't have one haha where would I be able to find that at a store?

you have to open the case, and install a piece of metal between the two holes labeled BOOT.

https://www.miataturbo.net/attachmen...ine=1374243624




also, the CAS could be good, but the ignitor could be dead. Did you unplug the ignitor before you attempted to reflash the ECU?

Yes I pulled the ignitor plug before I tried to flash the ECU.

I'll have to open up my MS but in the pictures from the link I gave you, it already has metal coming up and what I needed to install was something that slips over the top of them.

have an old HD laying around? they typically have them on the back.

they are called shunts.

DIP Programming Shunts : Programming Shunts | RadioShack.com


anything that can contact the two pins will suffice; you'll only need it this one time and will remove it when done.

You're a dip shunt.

Ok, tried the following:

Opened up the MS and stuck a paperclip between the two boot spots and I wasn't able to flash the firmware because it says its not connecting

Attachment 185285
Attachment 185286
Attachment 185287
Attachment 185288

I ended up then removing the MS and switched it over to the stock ECU.

This is a video of it without the diagnostics bridged:

just requoting things you still haven't done to actually diagnose the issue.

Also, I'd go through all that hacked wiring right at the ECU connector. That one white wire I see is the CAS input to the computer; probably had a Bipes or MSD box at one point in time.



The response the portchecker gave back with the boot installed was correct. Sometimes MSI is a PITA to flash; keep trying. I remember building old MSI ecu's that might take like 20 attempts for them to finally connect and flash. Dunno why...

I'll continue testing once I get my battery tender. I've been cranking the motor and I'm worried that the battery will drain.

stop cranking it so much and fix the issue first. :)

I don't know where to go from here. I've re-hooked up the MS to the car in attempts to reflash the firmware. I disconnected the ignitor. I have a paper clip running from the two "boot" holes on the MS board.

I turn the car to "on" and do a port check and it reads the same as my previous screenshots.

I then open the 'ms2loader_win32.exe' and go through hitting enter. I then manually select the COM port which it is 4 according to Device Manager and then I hit enter it shows this:

https://www.miataturbo.net/attachmen...ine=1374263773

Com4...garbled reply...???

Which USB to serial converter did you buy? These are notoriously flaky pieces of hardware.

--Ian

It's possibly a bad CPU beyond being a reflash. I can send you a replacement for postage... Would have firmware and tune loaded.

I have the Serial-USB converter directly from DIYAutoTune's site because I know the risk of crappy converters. Since it is coming directly from the source, it would help eliminate that potential risk.

Braineack, that would be great if you could. Is it the whole unit or what exactly is it and would there need to be any work from my end to get it installed other than just PNP. Feel free to PM me if it's easier to discuss.

the CPU is that 64-pin IC with the white label on it in your pics.

http://www.diyautotune.com/catalog/c...cpu-p-105.html

And is that just a pull the old one and plug the new one in type job or is there soldering involved.

So I ended up switching out my CAS for one I bought from ClubRoadster. When I pulled my CAS, I noticed some corrosion so I went ahead and installed the CR CAS

Attachment 185272

Now onto the good stuff. Something obviously is not right. Watch the video but spark notes:

- 13 second mark: First turn to "On" nothing lights up on the MS.
- 16 second mark: After I turn the key to off, the MS lights up as if it is powered on and my FP continues to run with the "clicking noise"
- 1 min mark: Removed ignitor module and the ticking and FP stopped and the MS lights are off
- 1:32 mark: Turn the car back to on and the MS lights now blink, the FP and clicking noise is back but everything will stop when I turn the key off.

WTF?

the power issue is odd, i feel like someone else was having something like this happen. could be a bad ignition switch itself, but unplugging the ignitor was allowing the main relay to switch back off (something the ignition switch should have done).

does it ever do that with the sotck ECU in place? the MS having a bad firmware can do some really weird shit.



no soldering required, just get something long and flat to pry it up and install the new one in it's place. LMK cause I think it's a great sollution considering you cannot flash the CPU even with the boot jumper installed (although I'd still ask DIY for advice.)

Braineack,

Let's go ahead and start with replacing that CPU chip. If that doesn't work then I'll go ahead and send an e-mail to DIY.

Secondly, I'll work on putting the stock ECU back in and seeing what happens. All I need to do is hook the ECU back up and then plug in the MAF?

Pretty much... I have not personally worked on the 1.6s, but pretty much just work the steps backwards that are outlined in that how to PDF I sent you (that Brain made). He may have a few other specific tips for ya.

Be really careful prying with a screwdriver, it has a tendency to mess up the pins. :)

--Ian

Just an update. Got home and put the new ECU chip in.

Turned the car to 'On' and noticed that the MS light comes on, the "clicking" is still there but not as loud and still no check engine light.

I open TS and started a new project. It detected the MS and then brings me to the Port screen where it first said Successful and then if I click 'Test Port' again sometimes it goes to Failed and sometimes it says Successful

Attachment 185264
Attachment 185265
Attachment 185266


When I look at what looks to be the summary log, it says 'Invalid Data Received from Controller'

Attachment 185267

Any thoughts on where to go from here?

Is your USB port good, and the adapter? I know if I bump mine at all it will disconnect and get all pissy on me. Can you turn on comm debug?

I bought the serial from DIYAutoTune so the serial-to-USB should be good. My ports should be good as well as I've used them to hook my iPod and other devices to upload music.

well youre not getting garbage back from the CPU now, but it seems your connection is still hit or miss? have you been able to even connect to the ECU beyond the screens you showed to review the tune?

I am able configure the project but then after, it just says "Not Connected"

Would a bad ignition module cause all of these problems?

The screenshots and troubleshooting in my last post was with the ignition module removed. Then when I plugged it back in, there were these differences:

When I turned the car to "On"
- With the module unplugged, the ECU showed a power red light and there was faint clicking under the hood.
- With the module plugged in, the ECU did not show power red lights

When I turned the car to "Off"
- With the module unplugged, the ECU red lights powered down and the faint clicking under the hood stopped.
- With the module plugged in, the two lights on the ECU continued to show red and the clicking continued even after I had removed the key from the ignition.

To me, that sounds like something is wrong or faulty with the ignition module unless it is supposed to act this way when it is plugged/unplugged in.

So I ended up making a few purchases in hopes to narrow down my problems. The problem where the MS will sometimes mate up and be recognized tells me 2 things

#1: the MS itself is having problems and likely need a new one
#2: the cord from the MS to the Serial-USB converter is somehow faulty

Seeing how #2 is the cheapest route, I bought another cord from DIYAutoTune ($21). If the problem continues then I know that it has to be the MS ECU itself.

The other problem is that I was not getting a CEL. Based upon the 'No-Start Troubleshooting' thread, I ended up buying an ignitor module ($16) in case the previous owner shorted it and I ended up buying a MAIN relay ($17) (part#: JE16-18-811).

i'd think your relay is suspect; it's not the MS. the issue is intermittent power and constant power after the key is removed from the ignition.

Does the MSPNP have a power port on it? if so you should test it with a 12v power supply, out of the car, and see if you can connect.