Who would of known..........My secondary injectors decided to stop working. YA YA....4000 rpms it would hit a wall. Welp, simple fix I had one trailing and one leading plug dead, so I change them..........ha ha car runs like new. Anyone the CPU was seeing that the plug resistance wasnt there on 2 plug so the resistance on the injectors were affected and made my car sound like the engine blew. It lives again and I left 20 feet of rubber for proof. So if you secondaries stop working have no fear change you plugs. FYI, wondering if anyone else knew about this, it fix my 4000 rpm crap. This was the origanal post/problem: https://www.rx7club.com/2nd-generation-specific-1986-1992-17/injectors-541761/

now heres the cure.

-chris-

 

????

Eingrish??? What are you trying to say??? did you read what you wrote before posting?

And the CPU (body computer) has nothing to do with spark plugs or injectors. The Emissions or Engine computer (ECU) controls the spark plugs and injectors. Of course the ECU (and CPU) do not monitor the spark plugs, but rather the ECU does monitor the trailing coils tach signal.

 

sorry thats what I meant ECU.....duh. I was just shocked that due to the fact the secondaries stopped working because of the plugs. Wierd.............it never cross my mind thats it.

 

Ah so that is what you were trying to say.

Just so you know:

The trailing spark plugs have no effect on if the 2ndary injectors are working on a S4.

 

well just to let you know that might be so, but I had 1 trailing and 1 leading bad. After I changed the plugs my secondary injectors work like nothing happened Icemark. Its a wierd issue but thats the whole senario, believe it or not. Must of had something to do with the resistance in the electrical system. Im not shitting you.

 

what made you think your secondaries were not working???

And changing plugs has nothing to do with resistance. Let me see if I can find some basic automotive electronics manuals for you.

The whole concept of what you are saying is impossible. Perhaps you have/had other issues that you are not aware of.

Toss in, in that other thread, you were clueless about how the fuel injection system works... wanting to put in 550 injectors on a stock port Non turbo??? what were you thinking...

And then testing them with a meter??? You can't test them with a meter unless they are not even in the manifold. You can test to see if the ECU is firing them, but can't test to see if they are really working, when they are mounted in the car.

 

I think what he is saying is that two of his plugs fouled out and weren't firing. That was the problem the whole time. Anyways, glad you got it fixed.

 

See that would make sense...

But the garbage about injectors not firing because he had a bad spark plug is just stupied. Maybe he was drinking when he figured this out... that would make sense based on his first post in this thread.

 

um no fuel over 4000 rpm's did you read my injector post up above. Im not gonna re-explain my problem read. The secondary injectors didnt click when ignition was turned on. Im just trying to say somehow bad plugs lead to an injector problem. If you dont believe me after trying to figure out the problem for 1 week straight and changing the plugs why does my car work fine now. BTW it affected my 5th/6th ports to, werent opening due to the 2ndaries werent work now those work fine too. This whole thing is mind boggling.

 

um that was kinda unappropriate, I dont drink.

 

The ports weren't opening because you couldn't get the rev's up high enough to generate enough back pressure in the exhaust to open them.

 

I did read your messed up funky thread... it had some many miss-conceptions in it, it should have been deleted.

And Injectors don't click when you turn the ignition on. You don't really understand how they work do you???

The 2ndary injectors start working at 3800 RPM, so unless your car was underload at 3800+ RPM they would never even come online.


How do you have your aux ports activated???

 

electric conversion, wouldnt matter its runs on a rpm switch and pump

 

no **** icemark im not stupid along with the ports opening at 3800

 

ok then why dont you explain to me why my 5th/6th ports stopped working along with my secondary injectors, and it whouldnt go over 4000 rpms w/o sounding like it gonna blow. Then when I replace the spark plugs they the car all of a sudden runs like nothing happened. Oh look in the haynes manual on testing injectors um......page 141 section 18 in vehicle check on injectors. Then checking for resistance. It started as an injector problem............then all hell broke loose............replace the plugs, runs perfect.

 

what is your RPM switch using as a trigger input/tach lead?

See I could even believe a trailing coil being bad, and replacing that.

But a bad spark plug... nah, not gonna happen.


Dude.. that is checking for INJECTOR RESISTANCE. That is checking to see if the injectors are bad or good.

It has nothing to do what so ever with wiether they are firing, but rather simply tests is they are good or bad.

And as a very very very basic hint. If the resistance of the injectors shows they are bad, they never ever ever will get better again.

If the resistance test shows they are bad, it means the coils that work the actual actuator inside the injector have fried!, the Genie has escaped, they have gone to meet their maker.

<edit... can you see why I think this is and your other thread is full of crap yet???

I mean you posted this in that other thread:
The Crank angle sensor doesn't even feed the injectors or the coils... it feeds into the ECU. And by the way, how the ECU works, is that it sends a signal to the CAS, and when that signal drops to ground, it processes it to fire the coils.

But wait--- how does it fire the spark plugs- I can see you asking... Well let me tell you.

IT DOESN"T FIRE THE SPARK PLUGS.

It sends a ground signal to the ignitors. The ignitors, then ground the coil's neg lead, turning on the coil... which then creates around 20000 volts and that runs down the spark plug wire to the ... yep you guessed it--- the SPARK PLUG.

Now the trailing coil ignitors, send back to the ECU (and the tach in the dash, and the cruise control, and the power steering computer) a summed signal (a grounding A/C signal actually) that the ECU then takes and sends through and isolation array, and then the processor. The processor, then sends a signal to a couple of transistors, to fire the INJECTORS- but the processor also uses the inputs for the engine load and AFM position and a couple of other things to figure out how much fuel to inject.

Of course the 2ndary injectors would not even fire until at least 3800 RPM is reached and there is sufficent load on the motor and the AFM position says there is enough air moving in the motor.

So can you see now why it is impossible for what you are describing to actually happen???

 

Better listen to Mark!

Occasionally someone will post a thread and make conclusions that are just not possible, so when "Old Reliable" comes to your aide, digest what he is saying before you argue.

Do a test-Disconnect the leading and trailing plug wire to simulate the condition and then take it for a ride to see what difference it makes.