WOT breaking up? help..

[turbo96max]

Guys, I have put new plugs, tested with my friends wires, coil tested good, tried running car with the cam sensor unplugged, tried my friends maf, nothing doing

the car is not taking out timing (no knock)
have played with the fuel where o2 readings at leanest have been from 730 - 805, and still same breaking up
the car runs great part throttle, but full throttle i get what seems to be a one cyl ignition miss, the car still pulls, but its a constant miss. not backfiring.

what am i missing to check, can the o2 be bad? can the crank sensor act up this way? the car idles fine and it runs good makins power at part throttle, just doesnt like wot? the only code i have in 41 which started when i tested the cam sensor disconnect , which hasnt left, do i need to unplug the battery to clear the code?

 

[azbob]

Code 41 is for the cam sensor. This would cause a noticable breakup at rpm. Investigate the cam sensor conditions.

 

[TurboBuRick]

worn cam?

Sounds like the dreaded #3 exhaust lobe syndrome.

 

[WS6]

Sounds like the dreaded #3 exhaust lobe syndrome.

Time to cut that oil filter open

 

[turbo96max]

im almost sure that the reason the code 41 is on there bc i unplugged it to test the car with it unplugged, but it just hasnt cleared?? or should it clear on its own? i thought i needed to unplug the battery ??


cam lobe? before i pull out a cam, how do i diagnose it properly? shouldnt it pop through the intake if it was an exhaust cam lobe issue? wont the lifter knock? i want to eliminate all possibilities first? whats up with the cutting the oil filter???

 

[turbojd]

whats up with the cutting the oil filter???[/QUOTE]

Cut the oil filter open to check for any metal particles which will be in there if the cam lobe went bad.

 

[WS6]

whats up with the cutting the oil filter???

That's where my cam lobe ended up when it went bad.

 

[TurboBuRick]

Pull the driver side valve cover. With the cover removed, start the engine. Observe the movement of each rocker. Your looking for one that is not moving as much as the rest. May want to roll up a towel and lay it along the bottom of the head to soak up any oil.

Do the same on the passenger side if you don't find the culprit on the ds.

 

[turbo96max]

ok, got it, im going to take valve covers off against my own will as for the first time ever they are not leaking.if i dont see the valves moving equally ill suspect cam. will a bad crank sen act this way? should i clear the code by disconnecting the battery?

how is it that only wot is it an issue?

 

[TurboBuRick]

ok, got it, im going to take valve covers off against my own will as for the first time ever they are not leaking.if i dont see the valves moving equally ill suspect cam. will a bad crank sen act this way? should i clear the code by disconnecting the battery?

how is it that only wot is it an issue?

A bad or misaligned crank sensor can cause drive-ability problems but from your description it sounds like a worn cam to me.

To clear the code just unhook the orange wire by the battery for a few seconds then plug it back in.

At wot the motor moves the most air through it. If a valve is not opening all the way, it can not get air in or out the combustion chambers. In early stages of a worn cam, you only see a problem at higher throttle levels. As the lobe wears out more the miss will move into the lower power range also.

Make sense?