Thread: misfires after cam install

Looks like that guy does really nice work.

Heres a video-
http://s291.photobucket.com/albums/l...=VIDEO0011.mp4

Originally Posted by darkhorizon

whats the problem?

You guys are claiming that Im hearing things

I'll suggest that you answer some of the questions posed to you. Otherwise.. from the video that I found, btw your link isn't working, that it sounds like a normally cammed car to me. That surging at idle can be tuned out. It's pretty normal when you cam and mod.

Originally Posted by darkhorizon

Stock timing will give that little surge you feel, but other than that your wideband is reading a fairly healthy afr, and it should smooth out a bit if you raise the idle or just stop thinking about it.

O_o
We're gonna have to archive this one...Some serious mind tuning. LOL

Originally Posted by BillBoost37

It's pretty normal when you cam and mod.

I know what a cammed car sounds like and I understand the surge can be tuned out. If you cant hear it in the video then bring your ass down here and I will show you. But if this forum thinks this is a normal thing then this place is retarded.

Tim,

I install cams all the time. I'm also not the one with a problem, you have given us about a thimbles worth of info, a video in which all anyone seems to be able to hear is a normal sounding cam install. And you are going to call us retarded? This is the internet, you are typing and posting a video that doesn't give the viewer any obvious signs of issues.

If you'd like us to see or hear the problem, point it out. There's no need of calling names to people attempting to help you for free. It's pretty inconsiderate trying to belittle people when they are trying to give you a friggin hand with what you seem to believe you screwed up.

Think about it guy.

Originally Posted by gtptim

I know what a cammed car sounds like and I understand the surge can be tuned out. If you cant hear it in the video then bring your ass down here and I will show you. But if this forum thinks this is a normal thing then this place is retarded.

Perhaps you should take a look in the mirror...

fwiw, i had three dead cylinders at idle. when it came off idle, i'd have an intermittent misfire or 20, but i was also untuned.

Bill, i don't know if you want to do it in this thread or not, so send me a pm if you'd like, but could you give some insight into why the P0300 code needs deleted? this thread is extremely relevant to my situation

Our pcms read misfires through the knock sensors and detecting timing of the detonation etc etc. I'm no engineer or programmer, I would venture to guess that once we cam the motor it changes things enough that the pcm believes the engine is misfiring. Therefore you turn off the multilple misfire code (p0300) and the engine runs properly. You can still read the individual cylinder misfires w/o issues.

Originally Posted by darkhorizon

Actually in quite a few OS's turning off 0300 will disable the misfire detection system.

For which year(s) is this true dark?

Originally Posted by darkhorizon

Not 100% sure on that one... I do believe most of them will do this.

Buddies 04 comp g can still read individual misfires. And gets codes whenever a certain cylinder is missing enough

from what i've heard, the pcm gets the info from the teeth on the reluctor wheel, in our case the one on the harmonic balancer. it would make sense that the pcm would try to adjust timing, but i would also think that based on the fuel trims off the front O2 and the timing info, it could figure out spark timing. i mean the stroke is the same, i guess it just can't compensate for the increased speed of the piston. the thing that really confused me is that i never saw any KR on the aeroforce. does the engine have to be under load for that to show up?