Injector Circuit Code Error

[QuickSilverGSX9]

This problem is driving me nuts. I've tried everything to get this code to go away and nothing has worked. Can someone give me a run down on what could cause this kind of error? I'm fresh out of ideas...this is what I've tried:
-Swapped ECU's
-Swapped injectors (from 680cc to stock)
-Cleaned the connectors on both injectors and harnesses
-Made sure harness conections were secure to the injectors

Okay, I'm now at a loss, any help would be GREATLY appreciated.

-Bill

 

[steve]

Sounds like the only things left are the injector resistor pack and the wiring harness.

Steve

 

[QuickSilverGSX9]

Swapped the resistor pack yesterday, absolutely no change. Also, I believe my rough idle (and the car eventually dies if I let it idle too long) is somehow connected with this error code. I called a local shop and they advised checking EVERY SINGLE electrical connection back to the main harness. They said it sounded like a continuity issue.

-Bill

 

[PhoenixRPR]

You need to check the MAF. Hope this helps.

 

[QuickSilverGSX9]

I'm not sure what you mean by just saying "check the MAF". I've swapped MAF's to see if I could clear up the rough idle, and it didn't help. Also, it didn't help with the error code I'm recieving either. Any other ideas? I'm really frustrated.
-Bill

 

[steve]

Originally posted by QuickSilverGSX9
I called a local shop and they advised checking EVERY SINGLE electrical connection back to the main harness. They said it sounded like a continuity issue.

-Bill

I agree with the shop, the injector circuit is pretty simple and the biggest part is the wiring between the ECU, injectors, resistor pack, and power source. You've swapped the other parts at one time or another, ECU, injectors, and resistor pack without positive results. I've noticed the wires on my car are getting pretty stiff and prople have reported breaks in the harness in the past. It's time to get the multimeter out and measure each wire as you jiggle things around.

I assume you have cleared the code after each debugging session. Is there any thing about when the code get thrown that you can narrow down. Does it happen right away or after the car gets hot?
Do you know which cyl is having the problem?
Have you pressure tested the intake to make sure you don't have any leaks that might cause idle problems? Have you checked the coils on your ISC as well to make sure it's working?
It's possible for your rough idle to be caused by the injector error if both happen all the time but if you have a rough idle at times that you know all the injectors are firing you might have two different problems your fighting.

Steve

 

[QuickSilverGSX9]

Yes, every time I switch a part I reset the ECU (usually have to unplug the negative battery terminal anyways as a precaution), and the code is reported intermidently (sp?). I've started the car up and right away the CEL is on, then goes away and comes back on. I have noticed that as the idle jumps around (begins to get rough) that the CEL flashes on and off. It *seems* that as the idle jumps back up to around normal the CEL flashes and then when the idle drops (about to stall?) it goes away and then repeats the process. Also, I had assumed it was the 3rd cylinder having the problem only because my 680cc injector in that cylinder was vibrating/tapping. But, I swapped injectors back to stock and while none of them are now vibrating/tapping I'm still getting the same code and the car behaves the exact same...so, I have no idea if that injector was bad or not.

Yes I've pressure tested the intake track, however, when I did it air seemed to be escaping somewhere near the injectors, but it was a lot of air, as in the intake couldn't actually keep pressure. However, I'm not positive if this is because I was doing it incorrectly, had the improper equipement, etc. I was using an aircompressor with a regulator (two gauges, one showing the regulated pressure and then the gauge showing how much air you were pushing through the system (in this case my intake track) and I had my nozzle on the compressor side of the turbo (obviously). It was ONLY leaking near the injectors (possibly intake manifold gasket...I believe it is original).

Thanks for the input Steve, please let me know what you think of all this.

-Bill

 

[steve]

When an injector is firing it should tick.
When it's not (one or more) the engine will rund like crap and the CEL will come on. Once it fires again the light will go off but the code will be stored. When mine was failing I used my datalogger to disable cyls to see which made no difference and thereby knew that one wasn't firing. If the engine ran worst that injector was working.
Once I knew which injector wasn't working I could focus on figuring out why. I tried wiggling the wiring harness to see if that would effect the problem but it turned out in my case it was an injector that failed when it got hot.

If your hearing air near the injectors it could be a bad intake gasket but it's more likely that the rubber insulator on the bottom of the injector has gone hard and no longer sealing. That will cause problems all the time but intake vacuum might cause the injector to seal when manifold boost would leak past. Soapy water helps when looking for leaks. it will make bubbles at the leak.
If you can't pressurize the intake and maintain it you have one or more leaks somewhere.

Steve

 

[whitegst97]

I just got the injector circuit error and well the car runs like crap, this was all after replacing the TB gaskets and the O-ring from the biss screw. The car idles at the correct RPM but like crap, i disabled the injectors one by one and seemed like injector 3 is the crappy one. The vacuum is at around 18 in/HG. I had never had any injector problems prior to the replacing of gaskets but i don't think it's due to that since there isn't any leak, or at least vacuum leak. Any help would be greatly appreciate i need the car up and running by monday as it's my only ride. Please help out. Thanks in advance.

 

[PhoenixRPR]

My car got a code 41 (Injector Circuit) and also began running terribly upon any acceleration. In order to get rid of the problem I had to replace all the injector seals/insulators, check all the injector pigtails & connections to harness, replaced EGR valve (not related most likely), replaced wastegate (not related most likely), replaced MAF sensor, and replaced both ignition coil packs. Somewhere along those lines the problem vanished and the car runs outstanding now. Hope this assists you.

 

[whitegst97]

I found my problem one or two of my connectors was a little loose, had the clip off, my car is a 90 is a little old and they were all hard and brittle. I have another little thing to ask, not related to this but, my car is completely stock and well the low fuel trim shows 118, why is it so lean and it's also getting knock. Any suggestions, boost is 10 psi and all i have is a filter. Thanks

 

[whitegst97]

Another thing why dont fuel trims change at all in a log, it just shows like a stiched line and also the 02 trims don't move. It's true that for the 90 gst the 02 volts should be from .8 to .9 Thanks alot guys for all your help

 

[oparea12]

I found my problem one or two of my connectors was a little loose, had the clip off, my car is a 90 is a little old and they were all hard and brittle. I have another little thing to ask, not related to this but, my car is completely stock and well the low fuel trim shows 118, why is it so lean and it's also getting knock. Any suggestions, boost is 10 psi and all i have is a filter. Thanks

I'm having the same problem. Does anyone know where I can get new connectors?

 

[steve]

Does anyone know where I can get new connectors?

I think these are the right part for our injectors.
http://store.summitracing.com/default.asp?target=partdetail.asp&part=MSD-2400&N=120+400122+308224

Steve