No Start. Injector DTC. (Resolved)

[GSTwithPSI]

So, got the car all back together today and tried to start it up. It cranks but doesn't even try to fire.

1. I started troubleshooting by verifying the mechanical timing was good, and it was.

2. Next, I verified I have spark, and I do.

3. Next, I verified I was getting fuel from the pump. I activated the fuel pump using the test terminal and using ECMlink's interface. Both worked fine.

At this point, ECMlink began showing DTC 0041 (Injector Circuit Malfunction). I cleared the code and it reset again after some cranking. After seeing this, I grabbed a spare injector from my parts pile and plugged it into the harness. I can feel it clicking. I probed the injector plugs, and with the ignition on both terminals on the injector plugs are showing battery voltage.

1. I thought I may have wired in the quick disconnect plugs incorrectly. I verified they were all right according to the diagram below:


2. I grabbed about 5 different injectors from my parts pile. All were either 450cc or Evo 560cc. The all measured 2.6 ohms. I measured the ones on the car, and they too measure 2.6 ohms.

3. Next, I tested the resistor pack according to the diagram below. Each set of terminals showed exactly 6.1 ohms.

4. I swapped out the ECU just for fun. No change, same issue.

So, even though the resistor pack checked out, I'm leaning toward it being bad. I'm at a bit of a loss. What else would cause a 0041 code?

 

[GSTwithPSI]

Just swapped in a new set of injectors. No change /ubbthreads/images/graemlins/dunno.gif

 

[gtproto]

I got the same code today, my car drove fine for 50 miles then sounded like it was running on 3 cylinders check engine light came on pulled over and checked the code. I let the car sit a few hours and started up fine no issues and drove three miles back to my house. Im not sure what went wrong but under hood temps were really high sitting in stop and go traffic, its a built engine but still stock injectors I was thinking that was the problem but your not giving me hope for that. /ubbthreads/images/graemlins/dunno.gif

 

[transparentdsm]

Brett check you power translator. i had one of those go bad on me and the car jujst shut off and that was it.

 

[467]

A resistor pack is pretty simple, if it ohms out correctly it's hard to see how it could be bad. It seems like your getting no fuel but have you pulled a couple of plugs, cranked and looked or sniffed at the top of the pistons for fuel or vapor? The cam angle sensor has to be good but that would probably throw a code.

 

[bradrs]

Quoting GSTwithPSI:

1. I thought I may have wired in the quick disconnect plugs incorrectly.



What quick disconnect plugs did you wire in? Did you wire the later style 2G plugs in place of the original injector plugs with the spring clip? Did you just do this swap? Or has it been running for a while with the quick disconnect plugs in place?

 

[GSTwithPSI]

I did more troubleshooting, just to find more dead ends. The car just ended up just starting (reluctantly). I've never started a zero mile motor before. I'm assuming the lower than normal compression just made the car hard to start. I was being easy on the starter at first. Maybe too easy. I extended the cranking periods a bit, and then the car seemed to come to life. I guess it just needed a bit more cranking to build up some heat. As part of my troubleshooting, I did a compression test, to find 120 psi across the board. I don't know if that's low for a new motor or not, but that's the only thing I can think that was causing my issue. I'm talking out of my ass here, and making pure assumptions. All I know is the car magically started without me changing a thing. Maybe someone with more experience with zero mile motors can chime in.

After I cranked it for a bit I got a sputter. That turned into running briefly and then dying. That turned into running pretty good. The DTC went away magically, so who fuckin knows. Comments on how the car goes from not even trying to start to idling on it's own would be greatly appreciated. I've never really experienced a car that truly seems to fix itself.

After I got it to start consistently, I drove it around a bit and it ran pretty good. I did some 2nd and 3rd gear runs, accelerating moderately until I got into boost, and then engine braking back down in an attempt to break in the motor.

I got 16 miles on it before the intercooler pipe that goes over the manifold blew apart. I'm not sure if the heat killed it, or it was just its time. Either way, I have to come up with a better solution.

I shot a short video of the car idling. It's a crappy cell phone vid, and the sound is horrible. I apologize in advance, but wanted to put it up in case someone sees something blatantly obvious that I'm missing.
click

Thanks to everyone who tried to help out in this thread. I really appreciate it.

 

[Olson]

Same thing happened to me. Once I got it started it wouldnt idle at all. All i did was take it out on the road and ran 1-4 then came back home and it idled just fine. I think you are right on your assumption

 

[467]

Stock cr should give about 150 psi as I recall. Rings may need to loosen up after sitting a while.

 

[coyotes]

Glad you got it running dude, your hard work has paid off

 

[cheekychimp]

Are you still on standard compression ratio pistons or higher?

 

[Kibby]

164 is standard. 121 is service limit. 4g63 7.8 compression.

 

[prove_it]

My first thought about this is that the injectors were dumping fuel during your extended cranking and washed the rings out. Also a new engine will have lower compression until the rings seat. That compression number is low though.

What tuning software do you have? Guess I'm missing some valuable info. Specs for one.

 

[FlyingEagle]

Disconnect injector connectors.
Remove all 4 spark plugs.
Hold throttle wide open.
Battery at full charge, or even a booster to keep voltage/current up.
Crank until the highest reading is reached, minimum 5 (insert funny term for symphony of sound indicating 5 cycles) cycles.

Long duration/high RPM cams will likely drop compression reading and or skew leak down testing to a degree.

Chimpy pointed out pistons playing a role also, usually meaning higher compression as we likely have not seen anyone using < 7.8:1 CR, barring improper parts selection like a thicker head gasket, and stock thickness on the head (no skimming etc), and block deck.

New rings as stated above, don't help things but your compression should be very close, in very short order, to what it will settle in at during most of it's

service life.