finished the swap. beautiful. Go to start her up...sounds like misfire. Ok brand new plugs so its not misfire from the plugs. Throws a check engine light, it says p0203 and p0204 and some code for an alternator ground. So the p0203 and 04 are saying injectors 3 and 4 aren't firing. so I take the fuel rail out take the injectors across the street to the shop i use to work for during the summer. hook them up to the pulse tool and they are firing.... so its not the injectors but to be sure i put the stockers back in and same issue. Ok swap the harness from the injectors with a newer one from the newer motor. Same thing. Swap the complete ignition module from my buddies cobalt....still doing the same thing. So i take the plugs out 2 are dark 1 is a little dark and one is completely clean like the cylinder is shot. bust out the compression tool....205 all across all 4! awesome compression still not firing. so I pull a spark boot off one by one. cylinder 1 and 2 are firing but when i pull the boot from 3 and 4 the car doesn't run any better. so obviously cylinder 3 and 4 arent firing for some reason. even swapped the tps sensor.
maybe Because I have the altenator ground in the wrong location that is doing it? but i don't see how an altenator ground can do that unless i am wrong.
You might have something not hooked up right, or not hooked up at all. Your fuel injectors have power at all times. The computer will short to ground (which completes the circuit) and then the injector opens. Without the ground, a fuel injector will only have + going to it, and it will not fire.
SInce you just did a swap, I'd say you need to check over the wire harness. Get a diagram and go over things and check that every one of the grounds is hooked up. You're going to find quite a few.
yea but would a wrong ground cause 2 injectors not to fire? would'nt it cause all 4 not to fire?
do you know where the grounds would be located. I mean I will happily find it but I mean if you knew off the top of your head what is wat for ecos I would be very happy to go and find it
Also...
Make sure that you have the right injector wires going to the correct cylinder holes. If the injectors are firing at the wrong time this will happen too. The injector pairs should be the same as your spark plugs, 1&3 and 2&4.
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so on the harness lets say going from the left so starting at cylinder 1. that injector pig tail should be with the first injector but the next pigtail should harness onto injector 3?
yea thats what im saying i did cross them so how would I know what the order is/.
Maybe switch 3 and 4 around...they werent firing before maybe they would.
get a set of noid lights these things here
plug the gmpfi lite into the connector and if the light stays on solid or dosent come on at all your injector drivers are shorted/dead and you should get another pcm.
I just cant drive 55
K. Vega,Now With Vitamin Boost wrote:yea thats what im saying i did cross them so how would I know what the order is/.
Some cars have the cylinder number on there somewhere. Other things to look for is that typically the injector harness starts at one end of the engine. The longer the injector wire, the farther the injector is for that cylinder.
yea Im pretty sure i had that down but I will double check saturday morning when I am home. Any more ideas anyone? I need as much input as possible since I am trying to avoid a mechanic shop. Ive had the car for a year and it hasn't seen a shop yet nor do I want it to unless its completely out of my hands. Ive down all my own work on the car from simple oil changes to installs like the s/c and the motor swap and tuning. Id prefer to do it myself but if I cant then I have no choice.
Shifted wrote:Also...
Make sure that you have the right injector wires going to the correct cylinder holes. If the injectors are firing at the wrong time this will happen too. The injector pairs should be the same as your spark plugs, 1&3 and 2&4.
1&4 and 2&3...
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"Youth in Asia"...I don't see anything wrong with that.
Injector drivers in the pcm shorted or dead.
the code said that the injectors are not firing so that means you need to do a functional test using NOID lights.
start the car and put the gmpfi light in the connector if it blinks the driver is good if not you need a new pcm.
I just cant drive 55
instead of doing all of that i swapped out my pcm to my older pcm that also went bad and it got rid of the lights but the issue on that other pcm was still present. Dont ask me how two pcms went on me I have no clue...I feel like I own a dsm now lol. my brother's dsm eats ecus up like they are breakfast.
