help cat gods

What you're describing ............sounds like it hit the torque limit. I've heard it before..........it sounds like a misfiring cylinder, but not the same cylinder at every revolution. If you listen to this dyno run............does it sound like this? It's hard to hear the engine...........turn up your volume


http://www.youtube.com/watch?v=z7I6KAR1Xk4


Next test drive you take it on, do NOT lift off the throttle when it starts breaking up. I want you to see if it will recover on it's own. The RPM should drop 2-300 RPM, then the motor should come back to life with full power. As soon as it gets back to roughly the same power level it should start breaking up again.

You need to change the harmonic damper...........first and foremost.

Second is going to be look at the cam gear...........

The other thing I've been thinking about with your problem is.............the crankshaft. If this is the torque limit in the programming and from what you've described it has progressively gotten worse over time. The fact I've never seen an engine hit the torque limit that set a check engine light or fault code for timing sensor calibration. This makes me wonder if you've got a crankshaft with a crack in it. It's not broken..........it's cracked and sending a nasty harmonic through the engine under full load. The other thing that makes me think this is............you aren't building enough power with this engine to be anywhere close to the torque limit in the programming for this to be happening.

If it is the torque limit......you have an underlying problem that is causing the ECM to think you're producing a tremendous amount of power. This has to be a harmonic in the crankshaft.

change the harmonic damper

check the cam gear

next would be the clutch

last would be to pull the motor down looking at the complete front drive assembly and magnaflux the crank. I've had a guy that I help chase a bad vibration in his truck for a year..........it was getting progressively worse as time went on. He tore the engine down and sent the crank out for magnaflux testing..........the crank was cracked through a main bearing 2/3 of the way. This was an early 3406E with only a single timing sensor...........it doesn't have two sensors to read between and see crankshaft harmonics in the programming.

 

Timing calibration between the sensor..........will NOT cause what you're describing. In fact most of the time you can't even see a difference in the way the engine runs with this fault code active.

This is why I say you have a harmonic in the engine

 

My bad for some reason i thought the 22-11 would cause a derate, made a ### out of myself there. I hope you find the problem soon and when you do please let us know what it was.

 

This doesn't sound like the torque limit...........if you watch the dyno run you can see how fast the engine recovers and RPM actually picks back up quickly. The needle on the gauge to the left is the tachometer. The middle gauge is MPH and the right gauge is horspower being produced at the tires.

 

Have you tried to disconnect (Unplug) the Cam sensor and test drive it?
Then plug the Cam sensor back in and unplug the Crank sensor and test drive it and see what happens.

I have seen a similar thing when the Crank had too much end float due to Thrust plate wear.

 

Well you've found something, I know earlier you said you replaced the wiring harnesses..........have you checked them carefully? As engine load increases the wires to the injectors carry more electrical signal to the injector.........if the wires are breaking down under heavy load this will cause an intermittent problem also. The fact you have a timing sensor though is pointing the problem in another direction.

Do you happen to be an avid gun enthusiast? A 44 magnum might come in handy..........they punch nice holes in cast iron.