Car is running like crap after mods
#21
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I know this can be annoying, but take a deep breath, we can't help you if get overly frustrated. Now, we know you have a miss and I'm willing to bet your PCM is shutting down your fuel injectors in the affected cylinders to help prevent raw fuel from damaging your cat. So, don't use the injector unplug test as a decisive test. Every time you unplug something while the car is running, on an OBDII car, you will set a code and make your diagnosis tougher. First thing to do is recheck EVERYTHING around what you worked on. This includes connectors, hoses, gaskets etc... If you damaged anything as simple as the intake gasket around those cylinders, for example, those cylinders will lean misfire resulting in misfire codes and your PCM will shut down those injectors. Ok if everything appears to be fine visually. Reset your pcm and drive around until the SES appears again, but don't unplug anything, yet. Let me know what codes you pull up
P0200=Injector circuit problem
This could be anything from an open (electrically broken) injector to a bad driver (electronic switch) in your pcm.
Don't get scared. I'm just saying we need to diagnose a little more so we don't end up chasing our tails. If you part swap good parts for diagnosis sake your gonna end up with a new motor. Unless you have deep pockets then this is probably not the best route to take.
P0300=Random Misfire Detected
Chances are you got this code from all that swapping and unplugging you were doing.
P030X=Misfire in Cyl.# X Detected. Where X is the cylinder(1-8) that's affected.
These are much nicer codes as they help steer you in the right direction.
Finally, how are you retrieving these codes? Personal scanner or auto parts chain?
Let us know if you need any more help. I would be more than happy to walk you through some basic diagnostic steps. Just P.M. me and I'll respond as quickly as I can. I'll also keep an eye on this thread. Good Luck.
P0200=Injector circuit problem
This could be anything from an open (electrically broken) injector to a bad driver (electronic switch) in your pcm.
Don't get scared. I'm just saying we need to diagnose a little more so we don't end up chasing our tails. If you part swap good parts for diagnosis sake your gonna end up with a new motor. Unless you have deep pockets then this is probably not the best route to take.
P0300=Random Misfire Detected
Chances are you got this code from all that swapping and unplugging you were doing.
P030X=Misfire in Cyl.# X Detected. Where X is the cylinder(1-8) that's affected.
These are much nicer codes as they help steer you in the right direction.
Finally, how are you retrieving these codes? Personal scanner or auto parts chain?
Let us know if you need any more help. I would be more than happy to walk you through some basic diagnostic steps. Just P.M. me and I'll respond as quickly as I can. I'll also keep an eye on this thread. Good Luck.
#22
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What was stated above is another good approach. If you have an intake gasket leaking and spray some type of contact cleaner in the area, the idle will raise.
I didn't see it any where in your thread, but have you checked the main engine sensor fuse under the hood? My O2 harness fried on my header and blew the fuse. The car goes into a default/cripple mode and runs rich. If you have been unplugging lots of stuff, you might want to check that. I think the description says "Engine Sensor" or something to that extent. If this happens, my T56 wouldn't go in reverse cause my reverse lock out solenoid was functioning. Not for sure what happens on auto either.
I didn't see it any where in your thread, but have you checked the main engine sensor fuse under the hood? My O2 harness fried on my header and blew the fuse. The car goes into a default/cripple mode and runs rich. If you have been unplugging lots of stuff, you might want to check that. I think the description says "Engine Sensor" or something to that extent. If this happens, my T56 wouldn't go in reverse cause my reverse lock out solenoid was functioning. Not for sure what happens on auto either.
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I have rechecked all hoses, wire, gaskets, and connectors. I reset the pcm. I again am getting the P0200 code but now instead of P0306 I get P0305 and sometimes over 2,000 RPM I will get P0300. I have a hand held scanner that I am using. I did not just start unplugging injectors I was clearing the codes then letting the car run for a bit then I would unplug an injector then reset the codes. I have checked the coil packs and they seem to be working. I replaced the o-rings on the injectors and replaced the spark plugs. Any more ideas before the car goes to the doctor? What puzzles me is how it changed from P0306 to P0305. Also I am getting a lot of liquid out of the exhaust with a light gas smell. Is it possible that the O2's or the cats are bad but not throwing a code?
Thanks
Thanks
#26
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I do not have any pictures yet but the coils were relocated under the cowl. I can get pictures in the next few days to post up. I did the relocation exactly like the directions said from Thunder Racing.
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Originally Posted by 1BAD99TA
I do not have any pictures yet but the coils were relocated under the cowl. I can get pictures in the next few days to post up. I did the relocation exactly like the directions said from Thunder Racing.
If the O2s are bad or the cats, it would throw a O2 sensor or catalyst efficiency code.
#28
Originally Posted by WFOWS6_IL
I'll keep checking back cause I'm curious to see what's wrong here. Something sounds fishy.
Last edited by LS1_TA_2002; 05-03-2007 at 07:28 PM.
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I was just thinking an I remembered that just after the mods the fuel line popped off and sprayed gas all over. I think the O2 sensor on the driver side may have gotten soaked. Is it possible this could cause the problem? I just did the spark test on all 8 cylinders and everything is good so the coils must be good.
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Originally Posted by 1BAD99TA
I was just thinking an I remembered that just after the mods the fuel line popped off and sprayed gas all over. I think the O2 sensor on the driver side may have gotten soaked. Is it possible this could cause the problem? I just did the spark test on all 8 cylinders and everything is good so the coils must be good.
My buddy that works at the GMC dealership in town has a nice modus scanner. It can tell you injector pulse rates and what percentage of fuel you are waisting per cylinder. Those "AutoZone" type scanners aren't nothing special. Might want to take it somewhere to get a fuel diagnostic test.
Are you anywhere near central IL?
#33
Originally Posted by 1BAD99TA
I was thinking about taking it the to dealership when I get time.
#34
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I think I finally got it!!!
I replaced the driver side O2 sensor and the car is running very good. I am still getting the P0200 code and the P0306 but I am no longer getting the P0300 and P0305. The idles perfect and takes off like a bat out of hell. The SES light does not flash anymore. I am going to replace the O2 on the passenger side and see if that takes care of the other codes. I know it sounds crazy but it seems that the O2's were the problem.
Thanks for all of your help I really appreciate it!!!
I replaced the driver side O2 sensor and the car is running very good. I am still getting the P0200 code and the P0306 but I am no longer getting the P0300 and P0305. The idles perfect and takes off like a bat out of hell. The SES light does not flash anymore. I am going to replace the O2 on the passenger side and see if that takes care of the other codes. I know it sounds crazy but it seems that the O2's were the problem.
Thanks for all of your help I really appreciate it!!!
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I guess I was wrong. The car ran good for a few miles and I got all excited.
I have now discovered that the #6 injector harness is grounding out on the yellow wire. I did the test with the meter on DC and one wire on the positive battery terminal and the other on the yellow wire and it shows 0. When I check the other injectors it show about 25. How do I track down this kind of problem?
I have now discovered that the #6 injector harness is grounding out on the yellow wire. I did the test with the meter on DC and one wire on the positive battery terminal and the other on the yellow wire and it shows 0. When I check the other injectors it show about 25. How do I track down this kind of problem?
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Off hand, I'm not for sure. It must have been pinched somewhere along the way when relocating the coils. Just track the wire up as far as you can till it gets power. I will try and take a look at my harness later tonight if I remember. I've got it all boxed up till my new motor is done.
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Originally Posted by 1BAD99TA
I got it this time. The wire was stressed from installing the intake. I spliced the wire back together and took it for a 2 hour drive with no problems.
Thanks for all of your help!
Thanks for all of your help!