MS2-Misfiring - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


MEGAsquirt A place to collectively sort out this megasquirt gizmo

Reply
 
 
 
LinkBack Thread Tools
Old 07-24-2012, 12:03 AM   #1
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default MS2-Misfiring

I have a '99 with 1.8 motor, Toyota COPs and turbo, running a MSPNP.

Here's the issue: I parked the car 4 days ago after driving home from work; the car has been running pretty much flawlessly with the MS tuned with VEAL. The next day I started the car up and noticed that it was misfiring pretty noticeably, so I took it for a quick drive around the block and the misfiring didn't go away through the rpm range. I thought that the tune may have gotten corrupted somehow, so I ran VEAL again and it enriched the entire fuel map by and avg of about 10 pts. The fuel map is incredibly messed up now, so the tune that I attached has that awful map that resulted from running VEAL after the misfire started.

I figured it had to be something other than the MS at that point, so I checked each of the COPs and spark plugs. All 4 sparked without a hitch when I pulled each individual coil and spark plug and cranked the motor. I checked the fuel system and didn't notice any leaks or anything out of the ordinary. I pulled the filter off the turbo and it looked like it was rotating normally.

Fuel, air and spark all seem to be there, I'm wondering if there may be something wrong with the MS picking up a signal or a sensor going out. I'm not ruling out that it couldn't be a mechanical/electrical problem that is causing the misfire, though.

I ran a quick log driving down the street, and I'm hoping that someone will be able to see something in the log that I'm missing.

Thanks in advance for any help!
Attached Files
File Type: msl 2012-07-23_21.41.46.msl (251.2 KB, 73 views)
File Type: msq CurrentTune.msq (80.0 KB, 102 views)

Last edited by ShadowZ; 07-24-2012 at 01:10 AM.
ShadowZ is offline   Reply With Quote
Old 07-24-2012, 03:18 AM   #2
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

Using test mode, test all 4 injectors by replacing them with a 12V test light.
Reverant is offline   Reply With Quote
Old 07-24-2012, 07:30 PM   #3
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

I checked each of the injectors using test mode, but only injector 1 and 3 showed voltage, no matter which injectors I had selected to test. Maybe I didn't set up the test mode correctly?
ShadowZ is offline   Reply With Quote
Old 07-26-2012, 03:51 PM   #4
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

I checked all of the wiring connections for the injectors and COPs, checked all vacuum lines.

I put everything back together to see if anything changed with the misfire, and when I started the car, the motor started idling at 3000 rpm, and the misfiring is still there. I immediately thought that it could be a vacuum leak, but I've checked all the lines and can't find one.

I'm totally at a loss what the issue is now...
ShadowZ is offline   Reply With Quote
Old 07-26-2012, 04:11 PM   #5
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

Quote:
Originally Posted by ShadowZ View Post
I checked each of the injectors using test mode, but only injector 1 and 3 showed voltage, no matter which injectors I had selected to test. Maybe I didn't set up the test mode correctly?
Are 2 and 4 getting power?
Matt Cramer is offline   Reply With Quote
Old 07-26-2012, 06:04 PM   #6
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

Just did a test right now, and injector 2 and 4 are not getting any power.

I disconnected the COPs and pulled the connectors off the injectors, then cranked the car and measured for 12v. 1 and 3 got a solid voltage, but 2 and 4 were basically 0.
ShadowZ is offline   Reply With Quote
Old 07-27-2012, 10:53 AM   #7
Supporting Vendor
 
Matt Cramer's Avatar
 
Join Date: Sep 2006
Posts: 2,266
Total Cats: 51
Default

Check your fuses and wiring then.
Matt Cramer is offline   Reply With Quote
Old 07-27-2012, 11:40 AM   #8
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

Fuses are all good, and I pulled the injector harness off the car and went through it wire by wire, an it looked like all the connections were fine.
ShadowZ is offline   Reply With Quote
Old 07-27-2012, 01:43 PM   #9
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

what are you testing for voltage, the white/red wires right? you're saying that 2&4 don't have 12v on the white/red?

just turn the key on and check...it's a constant supply.
Braineack is offline   Reply With Quote
Old 07-27-2012, 01:56 PM   #10
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

On the injector connectors, there's a white/blue wire that is shared by all 4 connectors. The other wire on each connector is a different color for each one.

I was looking through a wiring diagram, and it looks like the white/blue wire connects to the main relay and the 4 other wires go straight into the ECU.

I need to check them individually again, but should both wires in each connector have a constant 12v?
ShadowZ is offline   Reply With Quote
Old 07-27-2012, 02:30 PM   #11
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

no. one is power, the other is a switched ground from the MS, that activates the coil.

all injectors should see 12v, and the MS provides the ground.


this will determine if it's an issue with the injector drivers on the MS, or the engine harness/fuses.
Braineack is offline   Reply With Quote
Old 07-27-2012, 06:59 PM   #12
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

Did another test with a better 12v test light, and the white/blue wire is getting 12v to each injector, but the other wire for each connector is not getting 12v. Now it looks like all 4 injectors aren't getting a signal from the MS, but the white/blue wire is getting a solid 12v.

I checked the voltage of each one with the COPs unplugged, while cranking the motor.
ShadowZ is offline   Reply With Quote
Old 07-27-2012, 11:36 PM   #13
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

I'm assuming that since the 4 wires that go straight into the ECU didn't have 12v, that the issue is with the injector drivers or something in the MS?
ShadowZ is offline   Reply With Quote
Old 07-29-2012, 04:36 AM   #14
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

Remove the ECU, switch the ignition on, measure the voltage on pins 4W,4X,4Y,4Z on the harness connector.
Reverant is offline   Reply With Quote
Old 07-29-2012, 10:52 PM   #15
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

I pulled connector 4 out from the MS and checked the voltage on each of the pins on the MS. 4Z didn't have 12v when the ignition was on, but 4W, 4X, and 4Y had 12v.
ShadowZ is offline   Reply With Quote
Old 07-30-2012, 04:12 AM   #16
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

You better check that then, as you understand, this has nothing to do with the MS.
Reverant is offline   Reply With Quote
Old 07-30-2012, 10:24 AM   #17
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

Only 3 out of the 4 pins on the MS had 12v, aren't all 4 supposed to have 12v?

I measured the MS and wiring harness side of each of the connections, only the MS side had 12v, but it was only on 3 of the injector pins.
ShadowZ is offline   Reply With Quote
Old 07-30-2012, 12:58 PM   #18
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

Wait, you are supposed to check the wiring harness-side connectors, not the MS-side connectors.
Reverant is offline   Reply With Quote
Old 07-30-2012, 01:05 PM   #19
Junior Member
Thread Starter
 
Join Date: Jun 2009
Location: SATX
Posts: 48
Total Cats: 0
Default

Right, I checked both. The wiring harness connector didn't have 12v to any of the pins. Are they supposed to? I thought that the MS would supply the power?
ShadowZ is offline   Reply With Quote
Old 07-30-2012, 01:07 PM   #20
Supporting Vendor
iTrader: (10)
 
Reverant's Avatar
 
Join Date: Jun 2006
Location: Athens, Greece
Posts: 5,441
Total Cats: 198
Default

Yes, they are supposed to, with the ignition on. Power is provided to the injectors through the white/blue wire, and the MS activates the injectors by grounding them.
Reverant is offline   Reply With Quote
 
 
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:23 AM.