View Full Version : Car is running like crap after mods


1BAD99TA
04-13-2007, 09:33 PM
I just did the following to my car last week and now it idles fine but when I put it in gear it start to shake. While driving when I hit 1500 RPM the SES light starts to flash and continues until I go to stop and around 500 RPM it stops flashing and stays on (I delete the EGR and Air a couple of years ago so the light has been on since then). When I sit at a stop light the car really vibrates BAD.

Took intake off and painted
Replaced Oil pressure sending unit sensor
Replaced MAP sensor
Coils relocated
New fuel rails
lowered car

I have checked the plug wires both at the plugs and on the coils and they are tight. I have checked for pinched vac hoses and they are all fine.

What the hell could this be??????

3.4camaro
04-14-2007, 11:11 AM
go get the codes checked at autozone. That will point you in the right direction. Flashing SES = misfire. The code might tell you which cylinder.

What kind of plug wires did you use? The plugs might not be getting enough spark with the longer wires. longer wires means more resistance.

1BAD99TA
04-14-2007, 11:49 AM
I used the thunderbolt wires that came with the Thunder Racing relocation kit. I will get the codes checked

edwardswb
04-14-2007, 11:51 AM
don't bother with the codes yet, check your wires. I had the same problem with those wires because they were a bitch to get on all the way. After I got em on, they have been great.

1BAD99TA
04-14-2007, 03:27 PM
I have rechecked the wires and they are in tight. I ran the codes and I am getting #6 misfire and Injector circuit open. I unplugged the #6 injector and the car run the same with and without it. Does this mean the injector is bad?

edwardswb
04-14-2007, 03:30 PM
I wouldn't say bad, could just be clogged.

1BAD99TA
04-14-2007, 04:01 PM
What should I try to unclog it? Does it hurt the car to drive it like it is?

EDS01SS
04-14-2007, 04:04 PM
might not even be your injector.......check to see if you are getting power at the connector.I have had a problem with the main connector for the coils not connecting right. make sure that is all good first

qwkta98
04-15-2007, 11:12 AM
change ur plugs

1BAD99TA
04-15-2007, 01:51 PM
I am going to replace the injector and see what happens. I swapped the wire around an still threw a code for the #6 and the injector. I did have an injector that was very dirty while I did the intake and rails. I just wiped it off (I should have replaced it I guess). Any I am hoping that solves the problem.

Thanks for all of your help

1BAD99TA
04-15-2007, 04:30 PM
Alright this is really pissing me off now. I have replaced the spark plugs, moved the injector from #6 to #8, moved the wires around to see if any changes. After doing all of this I am still getting the same f*&%ing codes (PO200 and PO306). What is left to check? Could it be the coil pack? How can you check the coil? The strange thing is the car ran perfect before the mod's.

robyrd
04-16-2007, 07:46 PM
are you sure that you didn't cross any of your wires. i know that this sounds obvious, but i have done it enough times to suggest it.

Platinum WS6
04-16-2007, 08:03 PM
i agree it just sounds like a bad connection on wire or bad injector connection

WFOWS6_IL
04-19-2007, 06:46 PM
I would agree in making sure you are getting some kind of resistance through the injection plug with the car running. Then swap coils around and see what happens. You can have the coils tested, but I have sometimes seen that to not be accurate. Sounds like you are getting close!!

1BAD99TA
04-19-2007, 08:30 PM
Well I swapped the injectors and still get the code. How do I check the resistance?

WFOWS6_IL
04-20-2007, 08:47 AM
Well I swapped the injectors and still get the code. How do I check the resistance?

I think resistance was the wrong word to use. Check the voltage from the plug that goes to the injector and the car should be running. I would assume it's in mVolts. Have you swapped coils?

LS1 car shouldn't be an exception, but if the coil doesn't have a good ground on the coil bracket, it wont work properly. I noticed you relocated the coils.

1BAD99TA
04-21-2007, 09:29 PM
Well I went out today to take the car for a spin and the battery was dead. One problem after another. Anyway I bought a new battery and put it in. The strange thing is I am still getting the same P0200 and P0306 (after clearing the codes). The car actually runs pretty good and does not shake me to death at stop signs. Is it possible that the battery was causing some of the problem? My SES light is still flashing but the engine is running somewhat smooth.

1BAD99TA
04-29-2007, 11:29 AM
Alright I am still messing with this. I have swapped the coil pack and wires from #4 to #6. After doing this I now get the P0300 and P0200 code. What should I check next? The car is burning gas like there is no tommorow. The exhaust has a horrible smell. Can anyone help????

hhidyhoneighbor
04-29-2007, 12:36 PM
had a buddy with a T/A ran like shit above idle and he had a injector o-ring leak and the only way they found it was spraying carb cleaner all around the injectors and intake area and BAM, when you did the mods you induced the problem, id put the old map back in and check for vacume leaks with carb cleaner, otherwise youve eliminated just about everything else. im not an expert or a mechanic however you did remove the intake and said you changed the fuel rails, just another suggestion. good luck bro

also dont remember what the PO200 code is but your PO300 is the same code im getting which leads back to the plugs i put in couple of weeks ago, shitty plugs equals various misfires, but you already changed those.
i think it has something to do with your intake/ fuel rails/fuel injectors.

just a thought

1BAD99TA
04-29-2007, 08:20 PM
I just replaced the o-rings on all injectors yesterday and I still get the P0200 code. I am now getting p0300 most of the time along with p0200. But every once in a while I get either P0305 or P0306 (never at the same time). I am very cofused at this point. I also unplugged each injector while the car was running and when I unplugged #4 and #6 (one at a time) the was no change in the idle but when I unplugged the other 6 the engine bogged down. Any ideas???

Thanks

LS1_TA_2002
04-30-2007, 08:40 AM
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.

WFOWS6_IL
04-30-2007, 10:45 AM
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.

sscrazy
04-30-2007, 04:02 PM
get a good tune

1BAD99TA
05-01-2007, 07:19 PM
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

LS1_TA_2002
05-02-2007, 04:18 AM
Is there any way you could post a pic of your setup? Of particular interest to me is your coil relocation setup. Thanks.

1BAD99TA
05-02-2007, 08:19 AM
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.

WFOWS6_IL
05-02-2007, 08:38 AM
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 you are still uncertain about the coils, go and buy a 20 dollar pen type spark tester from the Matco or Snap-On man. Hold it up to the wire and if it's flashing, it's good. I'll keep checking back cause I'm curious to see what's wrong here. Something sounds fishy.

If the O2s are bad or the cats, it would throw a O2 sensor or catalyst efficiency code.

LS1_TA_2002
05-03-2007, 05:37 AM
I'll keep checking back cause I'm curious to see what's wrong here. Something sounds fishy.

+1 Me too.

1BAD99TA
05-03-2007, 05:34 PM
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.

98ws61le
05-03-2007, 10:59 PM
id like to watch this thread

WFOWS6_IL
05-04-2007, 08:43 AM
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.

I've never tested soaking a O2 in gas..lol! Not for sure on that, but it should throw an O2 sensor code. Lucky that didn't start a fire.

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?

1BAD99TA
05-04-2007, 08:23 PM
No I am in Northern IL on the Wisconsin border. I was thinking about taking it the to dealership when I get time.

LS1_TA_2002
05-05-2007, 04:43 AM
I was thinking about taking it the to dealership when I get time.
Good luck with the dealer they can be pricks :thefinger sometimes if you have a lot of mods on your car.

1BAD99TA
05-05-2007, 06:10 PM
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!!!

1BAD99TA
05-15-2007, 08:59 PM
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?

WFOWS6_IL
05-16-2007, 08:38 AM
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.

1BAD99TA
05-16-2007, 02:31 PM
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!

WFOWS6_IL
05-17-2007, 08:11 AM
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!

Sweet man! Glad to hear it's all worked out!