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Backfiring after cam install!!!!!please help!!!!

Old Mar 5, 2009 | 08:49 PM
  #31  
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Ok. Thanks guys. That gives me a lot of options. I'll check them out and keep everyone posted.
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Old Mar 6, 2009 | 03:01 PM
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I would put a good amount of money on the fact that your timing is off. Those symptoms have it written all over it. My dad and I swapped a GM 2.4L out of my friend’s 99 Grand Am because he never checked the oil and those motors tend to leak oil out of the cam covers. Needless to say, his motor started knocking. Well, we put a water pump on the car since those are ran off the timing chain and very time consuming if the motor is in the car. We thought we had it timed correctly because we fired up the engine and it ran beautiful at idle (similar to your truck). However, when we gave it gas it was backfiring and missing like crazy. So, we looked at the timing chain again and the chain wasn’t tight b/t the two cam gears. So we got it on correct and it ran great! I would check your crank to cam timing.
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Old Mar 6, 2009 | 03:15 PM
  #33  
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Check your compression and report back. That will tell us if you're off time or NOT
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Old Mar 6, 2009 | 05:18 PM
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I'll check tonight and update you guys.
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Old Mar 7, 2009 | 12:04 AM
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Im with the other two...check to make sure that you didnt get off on the cam and crank timing marks...if its studdering, check the coolant temp sensor on the front of the drivers head, ive accidentally bumped it out before, and it looked plugged in.
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Old Mar 7, 2009 | 01:53 AM
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I would double check and make sure you really do have the marks lined up.
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Old Mar 7, 2009 | 07:34 AM
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I didn't get a chance to look last night. Does anyone think I could have pulled a wire or something out maybe. Like a ground. When it backfires and misses it's random. That kinda makes me think maybe bad ground? I am going to try and do it tonight. I have been really busy lately. My wife is scheduled tomorrow to be induced with our first kid. I know I won't be able to do it next week, that's why I'm kinda in a hurry. I will try and look at it tonight. Thanks everyone for all your help, and I will keep you posted.
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Old Mar 7, 2009 | 07:45 AM
  #38  
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I'm with the the guy's that think the cam is a tooth off. First thing I'd do is check compression and go from there...
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Old Mar 7, 2009 | 07:00 PM
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Originally Posted by hirdlej
Check your compression and report back. That will tell us if you're off time or NOT
I'm with hirdle, the very first thing you should do is a compression test. If all cylinders show problems, you're a tooth off. If one or two are off, check your valvetrain to that/those cylinders. Stop chasing your tail and do some troubleshooting. You will find the problem.
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Old Mar 7, 2009 | 07:11 PM
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Originally Posted by hirdlej
You're off a tooth, classic symptom
Thats the first thing that came to my mind when I read the title of the thread.
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