My car is going into limp mode when I start it while it is warm. Once warm it will not come out of limp mode until the engine has cooled and the ECU is reset. It is giving me code 73, which is - Rear Secondary Injector open circuit. I have the upper intake manifold off and tried testing the injector with an ohm meter however I don't think I am doing it right. For some reason the ohm meter reads 0, which is the same as if I jump the probes. I thought it could possibly mean the injector is faulty so I tried it on a different injector in a different car but it still reads 0. I guess I am doing something wrong.

Is there any other way to check to see if the injector is good? How many injectors are there total (just one primary and one secondary?). Does anyone know a list price for a new one from Mazda by any chance?

Thanks,
-Charlie

 

I've been reading through the shop manual and they have a pretty good trouble shooting/explanation for what causes a code 73. I am pretty sure I will be able to solve the problem. I have a new question though...

Should I buy OEM Mazda or go with aftermarket of equal flow rate?

Thanks,
-Charlie

 

Don't screw around with aftermarket injectors; Just go with Mazda and be safe.

According to my FSM, the resistance for the injector should be 13.8 ohms at 68F. If you are reading 0, either your injector is bad, or you're doing something wrong. Did you set the scale on the multimeter correctly? i.e., it is reading in ohms and not kiloohms, or something like that?

FYI, there are two secondaries and two primaries.

 

send them to RC engineering to have them cleaned, that way you'll know for sure that they're working properly. You should do that anyway since you have them out. Also, change all the o-rings, insulators, FPD, FPR, etc...

 

The ohm meter I have only does ohmsx10 and x1k - I guess it isn't good enough to read 13.8. I tried it on a good injector in another car and I got the same result so I must be doing something wrong. I might pull the injectors out and take them up to mazda for them to test.

-Charlie

 

ohmsx10 should work fine. Make sure the meter is not in "continuity" mode (where you get a beep if you touch the two leads).

 

How fast is RC's turn around? I've got all of my injectors out to change my FPD and FPR right now.

 

http://www.rceng.com/service.htm

 

Hah, I skipped right over the damn turn around time the first time I went to the page