I had this problem once with my car years ago.

Exactly the same issue. I tried shutting down the car and restarting it but nothing changed. For some reason I don't know why, I disconnected the battery for a few minutes and reconnected it and the problem went away and never came back...

 

Doesnt the resistor pack just convert the high imp signal from the ECU to the low imp signal the S4 injectors require?? If it was faulty, how would I still be getting power to my injector clips?

 

Yeah. All it is, is six ohm resistors the power for the fuel injectors has to pass thru to get to the injectors. Five wires. One is 12vdc from the EGI INJ fuse and it feeds the resistors. The other four wires go directly to the fuel injectors from the other side of the resistors. IF you have voltage at the injector plugs, and you do, then I don't really see that being the problem at all.

The injectors solenoid reads about 2.1 ohms and then you combine that with the six ohms of the solenoid resistor for a total of eight or so ohms resistance in the wire going to the ECU.

Kinda sorry I mentioned that thread.

 

Hrm, think it would be worth buying a used N326 ECU and giving it a shot? Im pretty much stumped now. If that doesnt work, a MS with a sparkling new harness and sensors is in my future lol.

 

So, I installed a new injector resistor pack and I can actually redline in gear now.

 

Happy you. I guess I'll have to start believing the resistor package can cause problem like that. Oh well. Guess I was wrong. I'd love to own that old resistor package for curiosity reasons.

 

what was the resistance of the old resistor pack? and where you found a new resistor pack?and what was the resistance of the injectors? why these question cause im having the same problem as you are having.

injector resistance: 2.6 on the secondary injectors , fsm saids the spec is 12 to 16 ohms

what is the specs for the resistors pack?

 

Im actually not sure how to check the resistance on the resistor pack. I am kind of retarded when it comes to using my multimeter. If someone could give me a quick walkthrough of what pins to check for what, I could get you guys some numbers. Im not sure of the resistance on my injectors either. What should it read? When I tried testing my bad one, I think it was reading around 6, but I doubt I was testing the right pins.

After talking to a friend who had the exact same problem a few years ago, I posted a WTB thread in the parts section and got one for change. Swapped it in and my problem was cured. Hailers, you can have my old one if you want to pay for shipping. I dont have any need for it.

 

On a 86-87 1/2 car, with low impedence injectors, they read something like 2.2 or 2.3 ohms. Your sound like low impedence injectors. ON 87 1/2 and on they are high resistance and read like you say, 12 plus ohms.

The resistor package should read 6 ohms for each of the four injector wires. You put the meter on ohms, positve lead on the center prong in the package plug, and then touch each of the other four pins one at a time. Each should read approx 6 ohms.

Yeah. I'll buy that resistor package. I'll pm you and send you the bucks for shipping first.

Second jpg attached is of a reistor inside the solenoid resistor package.

 

Hailers, im that person shane was talking about. A year and a half or so ago i found out about this resistor pack when i was going through the same issue with my s4 turbo 2 (I doubt you remember the thread) my car was like that for about 8 months. but it was the resistor pack causing my problems. I found out when replacing random sensors 1 at a time.

Anyway ever since then I'm seeing more and more of these issues pop up with people. sometimes 2 a day. The main problem is the symptom is a little too similar to the infamous 3800 rpm hesitation and can falsely be identified as it. it also takes a paragraph to describe how the car is acting. Would be nice to officially label this problem the resistor pack cut out or something appropriate like that to simplify things and minimize confusion.

I do not know near as much about electronics as you do. I'm interested to see what you can find out from diagnosing Shane's faulty resistor pack..

 

well my car was made in 7/86 thats whats it said in the door jam

the resistance pack read: 6.5 ohms it that good?

and like i said thr injectors reads 2.6 ohms

 

Plenty good fine. Next time put both meter leads together. Read the resistance. Then deduct that amount from whatever your measuring. Injector plenty good fine also.

See jpg I attached out of the manual. It's in a post above.

 

then why the fsm saids that the 86-88 years the resistance on the injectors specs should be between 12-16 ohms? misprint? but any how im still going to check my pimeary injectors next weekend to see what it reads.

 

So, I tested my old resistor pack and it was within specs. It read 6.6 all around. To make sure, I reinstalled it in the car. The problem had disappeared. Hailers thinks the problem was merely a bad connection on one or two of the pins and that makes perfect sense to me. Anyways, thanks to everyone who helped diagnose this!

Alex

 

can you check your injectors resistance? im wondering?if its not too much to ask.

 

I checked the rear secondary a couple days ago and it read 2.6, which I think is within spec?

 

yes

 

can you get me the part number for i can go to the mazda dealership for i can buy one or see how much it cost, cause i went today and they coundn't find the part that i was asking for.

 

Would the Nippon Denso number be the same as what Mazda has on records? Im guessing it would be. Ill try and get the number tonight.

 

ok thanks

 

Today, I decided to calibrate my TPS to stop the surging I am having at low throttle. I think my cheapo multimeter was wigging out because I coundnt get reasonable readings for the TPS. I assumed it was bad since it was of unknown condition and on my new/used throttle body when I got it. I swapped my old TPS back on and the car repeated the problem like clockwork.

Even more to my surprise, The car repeated the problem with the TPS unplugged!

Im baffled. Im sure the 22 year old wiring harness might have something to do with it. Im ready to go Megasquirt and trade all these problems for a hand full of new ones!

 

any update cause i checked everything i think cause im still gotta check my grounds.

 

im at the same point here as well.. with TPS off, same dang problem, id like to have some one with a running S5 in london to stop buy and let me use his map to see if thats the prob, then il try his afm, its one of those 2 things, i did notice today the wires going to the cas are cracked and some wires where touched by the ground/shield on the cas wireing harness so il fix that in the morning as see if thats the prob, but ya im confused as well!!

 

i hav the same exact problem as u lol..

been at this issue for weeks.. Thelast thing ican try is the fuel pump or afm..

 

well the problem for my car, was the air temp sensor on the dynamic chamber, i just unplugged it