I think i have one high and one low impendance injector on my secondary rail. Over 3500-3700 rpm it sounds like it runs on one rotor almost (hesitation, all grounds are cleaned), and I can tell that somethings up. The front rotor is the one with the questionable injector, as i switched it out with a spare i had because the nozzle hat had a hairline crack in it. The spare was from the engine i got with my 88 gxl, and the engine is from my 87 sport when they still had the solenoid resistor. Would this lead to be my issue? I do have the 87 ecu and engine harness (N326) with the resistor connected.

 

My bet is that its cuz you mixed impedence. They work in to different ways, swap out for the correct one and it'll be fine.

 

I figured that would be the problem, I just wanted to be sure before I changed it out for nothing.

 

Test the ohms of the injector and you'll know if it's high or low. Takes all of a minute to do if that.

 

I'm positive its high, because Mazda switched from low to high in the 87.5 models, and the injector was from an 88. The only reason I did it is because at the time i didnt know that there was a difference.

 

but the high impedence injectors have an offset locating lug, the early model injector clips won't plug right into the late model injectors unless you cut that lug off the injector.

 

Or jam it..... Correct me if I'm wrong but can't that damage the ecu?

 

I didn't notice anything different about them, but I didnt really take too close a look... I just replaced the o rings and put it in, and plugged it into the wiring. I'll have to double check on that. If that is not the issue, what else could be the problem? It starts bogging at around 4k, and really bogs at 6k. For this reason i do not take it past 3500 because I don't know what the problem could be. My first thought though was that injector simply because that's when the secondaries kick in, and since I replaced that secondary and it never happened before that, it was my initial thought.

 

If you have battery voltage w/key to on at pin 3H (front secondary) then the plug is connected to the injector properly.

 

I will check. Pin 3H on ECU? Or on the injector itself?

BTW, satch, it does happen while at a standstill. Not just driving. I saw your post in a related thread.

-Fuel filter: new
-fuel pump (or wiring): known working condition
-fuel sock: unsure of condition
-fuel pressure: how do I check?
-clogged primary injectors: flow tested fine
-primary injector plug(s) loose: nope, triple checked
-dirty air filter: brand new RB unit.
-Pressure Sensor or TPS (TPS goes into full throttle position at 3000 rpm): will check as per FSM, however, known working obviously as I never had the problem before.

 

Pin 3H at the ECU (not injector).

 

Thanks, I will check tomorrow.

 

Problem fixed, as I suspected, wrong injector. Put the low impedance one back on, and it ran like a champ.

 

curious how it managed to fit the injector clip.

 

It might not have especially if he measured the ECU pin and did not have 12 volts w/key to on.

 

probably not, just hope that the clip isn't damaged and going to pop off at the next bump in the road.

FYI you can find bosch injector clips(also fit denso low impedence injectors) at the wreckers in most '93 to current GM vehicles. i got a pure assload if anyone is in need of clips for series 4 vehicles.

i got pissed off when all the parts houses stopped carrying them and now want rather rediculous prices to even order them($8+ each).

 

The clip wasn't even on completely, it was sort clamped on on one side, but not at all on the other. ECU showed 0 volts to it. Was a simple fix, but it has hard taking the hat of the injector without damaging it to put on the right one.