i am like 80% Sure that my primary injector is not firing at 100%, Is there a way to tell if the injector is firing without taking it out, I Dont have replacment injector at this time So i didnt tear it apart, but im trying to get more "proof" before i go spend money,

 

Put a stethoscope to it and listen for the pulses.

 

Sorry Adam, I don't have one of those and I don't think I could borrow an o-scope from work.

hoofhearted: What would the pulses look/sound like for normal injector operation, if ya don't mind?

Thanks
Joe

 

If you can get a good angle on the injectors, all you need to do is put a screwdriver, or something that will transfer sound, up against the injecter and the other end up to your ear. When you do this, you just listen for a steady clicking sound. Each little click is the injector pulsing and spraying fuel.

 

Too bad he wants to test the primaries on an S4.

Thanks, I kind of figured you would listen for consistency. I've heard other injectors before at idle and it is a very rapid click. I thought it was the pentle caps making the noise though which would be the same thing as the injector pusling.

Does anyone now off the top of their head what the pulse on time is of the injectors. Otherwise I can pull out the trust thick *** shop manual when I get home.

BTW: Adam, you didn't fill up at one of those gas stations with bad gas did you? Just trying to entertain other ideas.

Thanks
Joe

 

I would imagine its somewhere around 2.5ms or so...

 

I think i could have got bad gas. But i filled up at a shell station. not a 76. also got gas lately at ampm :| and cheveron ,. and some other place. forgot all the places i got gas. ill try the screw driver idea to see if i can get some sound from it, i didnt think of that one. thanks all

 

anyone ever hear of a Primary injector working over 1,200 rpm and Dropping off Dead below that.
i have a problem, the front rotor is lower on compression, even took it too mazda dealer, they told me what i allready knew. the front rotor is "SHOT" bad engine.

But Not so FAST TURBO..i told them i want my fuel tested. he takes a fast look at the fuel coming out of the hose, Its fine he says,,,
I bring the dang thing Home and do a little home test myself, I run Both Rotors By themselves to see what rotor works the best. and WHat do you think i found out?? # 1 rotor keeps Speed around 2k prolly more if i pushed it, and Brought the RPMs Down to see when it died out, Rotor one went from 2k to 0 SMoothly, Time for rotor #2 keeps speed at 2k Misses now and then sounds like ****. I drop it down a hair and Boom NOTHIN.. Am i right on thinking i might have a bad injector in rotor 2 or what, the dealer said my front rotor is toast but it works the best,

I guess if ya want something done right you gota do it yourself, Dang

 

I would check to see if you are getting a grounding signal at the injector before you go throwing parts at it... Sounds like an ecu or wire harness problem to me...

 

that could be. i wll keep that in mind also, both rotors seem to come online and work fine with alittle vibration At higher speeds. thats what made the guy at the dealer think that its compression. because it works fine at cruise. but he could be wrong because anything could cause poor idle. poor injector bad ground. or stuck open injector that works at higher speeds and floods at idle. thats what im starting to think. front rotor is like 69-70-75- rear is like 90-95-96.. yes front rotor is low However its not totaly dead yet like the dude told me, and it would run smooth even with the low comp. it was tested about 5 months ago and hardly changed at all. Not bad enugh to not make anypower at all at idle. i could go on and on. But I guess ill have to keep playing with it till i either fix it or drive it off a cliff,