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,

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.

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.

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

post your map...

ill get it posted.

attached is the msq ivebeen trying to get the car to run on.

4 injections per cycle eh?

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.

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

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.

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

high impedance 550cc rx7 injectors

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.

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?

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

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

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.

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?

how can you test the injector drivers?

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.

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.

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

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.

switched the injectors, now 2 and 4 runs, its looking like i have two defective injectors.

anyone else agree?

So in the first post you swapped the wires on the two injector channels in MS, and the same two physical injectors (1 and 3) still worked. Then you physically moved all four injectors in the rail (leaving the relationship of wiring - cylinder as before) and now the injectors that were in 1 & 3 are working in 2 & 4?

That's really, really odd. Particularly given your previous ohmmeter test. I'm not saying it's impossible, it just sounds really improbable. What's the history on these injectors?

If you take the injectors out of the car and apply +12 across each one, you should feel and hear a click as the plunger operates.

they were originally installed on this car with a haltech E6k, which ran up until i removed the haltech to go to the MS.

they are the red top 550cc high Z RX7 injectors, i believe they are from an 89.

just so i know for sure, there is no polarity for the injectors right, just that you have them all the same.

ill try the 12v bench test.

thank you Joe.

bench tested them last night, they all click, but i don't see much difference.

i also switched them around again in the intake manifold, now 1 and 4 run, and 2 and 3 do nothing.

confirms the diagnosis of bad injectors.

When you switch the wiring, you're switching it in the MS, or which wire you plug into which injector?

MS-I, right? Too bad. :-) If you had the break out board you could... And the better stim. Ok, nevermind. My only thoughts: RX-7 injectors come in pairs, so it's not impossible for them to have a widely different past, in pairs.

Have you tried moving them all down one? I.E. 1->2, 2->3, 3->4, 4->1 and see if it's not longer by pairs?

Still, I think you've got a reasonable idea, though if they are opening on a bench test it's a bit strange.

they worked last year, but with all my issues, i might have killed them.

i have moved them all around, and the problem follows the two questionable injectors.

good news, i can get new replacements for 58 a piece.