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-   MEGAsquirt (https://www.miataturbo.net/megasquirt-18/)
-   -   It runs, but only on cyl 1 and 3? any ideas? (https://www.miataturbo.net/megasquirt-18/runs-but-only-cyl-1-3-any-ideas-23862/)

jamiemiller 07-22-2008 10:13 AM

It runs, but only on cyl 1 and 3? any ideas?
 
I am getting the engine to run on 1 and 3 but nothing on 2 and 4, and no tack inside the car.(no biggie, if the thing runs i will be happy to fix the tach )

Ive replaced spark plugs(a few times),
checked for spark(spark on all four),
compression test(150-125-150-125),
changed the fuel in the tank,
played with the timing(now sitting at 72 degrees trigger angle),

i am running a V3 ms1, with dual vb921's direct drive to GM coil packs, using the input mods from DIYAT, and a relay board using DIY's relay harness, the rest of the engine wiring has been replaced due to previous Haltech E6k install, turbo, external boost controller, aftermarket fans,

I am using the MSpnp 96-97 msq file to get started. with the necessary changes for spark output and req fuel,

Zabac 07-22-2008 10:21 AM

What exactly are you doing with the ignition?

OBDII Miatas get tach from the ECU, so if you didn't mod your MS for it you will not have a tach signal.

jamiemiller 07-22-2008 11:15 AM

full standalone, running direct drive to gm coil packs, using the an NA cas, the MS is modded according to the DIY instructions, the tach signal works in megatune, just not on the stock tach in the dash.

jamiemiller 07-22-2008 11:18 AM

Last night i went through the schematics for the fuel injector section, to double check, everything is there and oriented correctly.

Braineack 07-22-2008 11:21 AM

post your map...

jamiemiller 07-22-2008 11:23 AM

ill get it posted.

jamiemiller 07-22-2008 01:03 PM

1 Attachment(s)
attached is the msq ivebeen trying to get the car to run on.

Braineack 07-22-2008 01:09 PM

4 injections per cycle eh?

jamiemiller 07-22-2008 02:54 PM

i was running it at 2 per cycle, then just to make sure i wasn't crazy i put it there to see if i was getting any fuel into the 2 and 4 cylinders.

jamiemiller 07-22-2008 02:55 PM

it actually idles on the map, only on two cylinders. amazingly rich i might add.

AbeFM 07-22-2008 02:58 PM

Heh, ask joe - joe had some issue where only one injector bank was firing durring start up.

But it almost sounds like wiring. It's almost certainly fuel, since 1/4 are paired for spark, 1/3 for fuel.

jamiemiller 07-22-2008 03:01 PM

injectors are wired to a relay board, inj1 is 2 and 4 and inj2 is 1 and 3.

high impedance 550cc rx7 injectors

AbeFM 07-22-2008 03:17 PM

I guess you could check for the power feed to the cyl 2/4 or whatever one isn't working, make sure that's good.

If you have an oscilliscope y ou're golden, otherwise, try checking it on the STIM for flashing lights, or put a light (LED, etc) on the injector line and see if you get anything there. My guess is you're not powering the injector. If you are, then it's time to check the wiring.

And find Joe Perez (you can PM him with that name) figure out what happened to him. I think it was only on starting.

Does the MS KNOW you have a second set of injectors? I think this is really a issue to be solved with the stimulator and software.

jamiemiller 07-22-2008 03:23 PM

both wires on all the injectors have 12v in ref to ground.

with the MS1extra firmware, i thought since there is no way to deactivate the second set of injectors, that both sets are working?

jamiemiller 07-22-2008 03:30 PM

https://www.miataturbo.net/forum/showthread.php?t=17031

found what joe perez was talking about, ill try it tonight.

AbeFM 07-22-2008 03:58 PM

I'm a little sketchy on the MS-I details. There's a chance it's not configured right, and doesn't know which pin to put the fuel signal out on? Maybe someone more familiar with MS-I could suggest something. But certainly putting a light on there would help.

AND FIND SOMEONE WITH A STIM! There shouldn't even be an option to buy the stim or not.

Lastly, there's a SMALL chance you burned out the drivers if you have low ohm injectors.

jamiemiller 07-22-2008 04:31 PM

i have the stim , ver 2.1 and it tested fine. there is no injector test on the stim that i have.

they are high impedance injectors.

would an led test light even be detectable by the human eye? for testing fuel injector outputs?

jamiemiller 07-22-2008 04:31 PM


Originally Posted by AbeFM (Post 286413)
I'm a little sketchy on the MS-I details. There's a chance it's not configured right, and doesn't know which pin to put the fuel signal out on? Maybe someone more familiar with MS-I could suggest something. But certainly putting a light on there would help.

AND FIND SOMEONE WITH A STIM! There shouldn't even be an option to buy the stim or not.

Lastly, there's a SMALL chance you burned out the drivers if you have low ohm injectors.

how can you test the injector drivers?

Joe Perez 07-22-2008 05:59 PM


Originally Posted by AbeFM (Post 286413)
There's a chance it's not configured right, and doesn't know which pin to put the fuel signal out on?

No. On the MS1, the two INJ channels are hard-coded. It's possible for INJ2 to be turned off, but not on the wrong pins. In addition to the stupidity I did which is linked to post 15 here, make sure that under Advanced, in the "Staged Injection" menu, Injector Staging Mode is set to OFF.


Originally Posted by jamiemiller (Post 286431)
would an led test light even be detectable by the human eye? for testing fuel injector outputs?

At low RPM, yes. In particular, start the MS up with the stim RPM turned down to 0. Increase very slightly to about 200 RPM and observe both LEDs flashing together. Increase RPM to idle, and observe the two LEDs pulsing in sequence.


Originally Posted by jamiemiller (Post 286432)
how can you test the injector drivers?

With a stim. Even the crappy Non-JimStim has LEDs to indicate the operation of INJ1 and INJ2.

jamiemiller 07-28-2008 12:00 PM

injectors are working, i swapped inj1 to inj2 and cylinder 1 and 3 still run great.

this has got me stumped.

next up, checking the injectors themselves. i measured the Z for them, they are 14.2 to 15 Ohms, i am going to switch them, see if it runs on 2 and 4.


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