Miata Turbo Forum - Boost cars, acquire cats.

Miata Turbo Forum - Boost cars, acquire cats. (https://www.miataturbo.net/)
-   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 07-30-2008 10:25 AM

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

anyone else agree?

Joe Perez 07-30-2008 11:26 AM


Originally Posted by jamiemiller (Post 288906)
injectors are working, i swapped inj1 to inj2 and cylinder 1 and 3 still run great.


Originally Posted by jamiemiller (Post 289876)
switched the injectors, now 2 and 4 runs, its looking like i have two defective injectors.

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.

jamiemiller 07-30-2008 11:34 AM

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.

jamiemiller 07-31-2008 10:43 AM

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.

AbeFM 08-01-2008 01:23 PM

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.

jamiemiller 08-01-2008 01:40 PM

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.


All times are GMT -4. The time now is 03:58 AM.


© 2024 MH Sub I, LLC dba Internet Brands