Car idles rough, has no power after h/c install
#22
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after i did the cam on my car it ran perfect my tune was scheduled for 4 days after and on the second day the same exact thing happened, wouldnt idle and it felt liek the power would die and come on and off, u need that tune asap
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i had a similar thing happen on my jeep i installed custom wires on it and it ran great took it out hunting and a week or so later it started running like **** finally it threw a code had it read multipal misfires changed the wires to a fitted set and it ran like a dream
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sounds like what happened to me after my ms3 install. everyone said check my 02s, and then my map sensor, then my mass air. car was constantly shaking and misfiring with the same symptoms you described. after ripping apart the engine i found my problem. i have an adjustable cam gear on my timing chain setup and i didnt tighten the bolts on the adjustable gear. while i was driving the cam was constantly retarding and advancing itself causeing the pistons to hit the valves. as a result the bent valves cause my car to have no vacuum. no vacuum caused the car to keep dumping fuel and was drowning out the spark and felt like misfiring. does your car smell like gas? that could be an indication of a similar problem.
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I dont think its a bent valve. I dont think the car would have run fine for a week and a half then bent a valve all of a sudden. It seems to me that if it were anything mechanical (broken valvespring, pushrod etc.) the motor would be making some sort of noise indicating mechanical failure. There are no abnormal noises coming from the engine, so i'm going to check for vacuum leaks, switch out my O2's if need be, do basic stuff and hope for the best.
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Those codes are Post Cat O2s not Pre Cat so they don't have anything to do with fuel managment. They only monitor Cat Efficiency to keep the EPA happy. Do you have a scan tool or just a code reader? You need to monitor your STFTs and LTFTs as well as your PRE cat 02s. It doesn't seem likely that the lack of a reflash would suddenly after 10 days cause your car to run like crap. It might cause certain driveability issues, but not to the extent you describe. What about vacuum leaks? Have you done the basics since this motor obviously has a problem. Compression or leak down test? P0300 is very common after a cam change so don't worry about that DTC for now. A reflash will cure that one. The Post Cat O2 DTCs shouldn't cause these symptoms either. I'd go back to basics especially if the engine did not exhibiting these symptoms BEFORE the H/C swap. There isn't a sensor or DTC for every engine problem. Sometimes you have to be a troubleshooter and a wrench turner.
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As Eallan said above, the errors are for your post cat O2 sensors not your primarys. Since your car is untuned, the PCM is struggling hard to find the right fueling. In that struggle it may have run too rich and fouled the primary O2s enough to compound the issue. Get it tuned.
#36
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dude, you'll never get the the bottom of this efficiently through a forum. None of us can see the motor. Heck, half the members on here don't have any mechanical ability and are just stabbing at what could be wrong, maybe a 1/4 of us have some mechanical ability and are giving decent advice or suggestions, and the other 1/4 of us are or have been mechanics but as you already know, none of us will have any good info or advice without the motor sitting in front of us when it comes to diagnostics. Point is, take it to your tuner, he'll find the problem and at the very least, you'll save tons of time and maybe some money, too.
Not to be disrespectful to any of you guys on here, but you all know that stabbing in the dark, although is a good intention, is probably only going to waste time and money for our fellow LS1tech members.
Not to be disrespectful to any of you guys on here, but you all know that stabbing in the dark, although is a good intention, is probably only going to waste time and money for our fellow LS1tech members.
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dude, you'll never get the the bottom of this efficiently through a forum. None of us can see the motor. Heck, half the members on here don't have any mechanical ability and are just stabbing at what could be wrong, maybe a 1/4 of us have some mechanical ability and are giving decent advice or suggestions, and the other 1/4 of us are or have been mechanics but as you already know, none of us will have any good info or advice without the motor sitting in front of us when it comes to diagnostics. Point is, take it to your tuner, he'll find the problem and at the very least, you'll save tons of time and maybe some money, too.
Not to be disrespectful to any of you guys on here, but you all know that stabbing in the dark, although is a good intention, is probably only going to waste time and money for our fellow LS1tech members.
Not to be disrespectful to any of you guys on here, but you all know that stabbing in the dark, although is a good intention, is probably only going to waste time and money for our fellow LS1tech members.
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#39
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Thanks guys. I checked over everything on the motor (plugs, o2's, hoses, etc) to make sure everything was good to go. Something changed because its not quite as bad. I also set up a tuning appt for next tuesday.