no backfiring at all the cam retard was withing specs on all the data dumps from -0.3 to +.9
A 7 minute drive showed 1801 misfires on cylinder #4 and 3966 on cylinder #6.
Injecter bank 1 average was 388.7ms, bank 2 was 3.5ms
At one point the knock retard was over 7 degrees and the puter backed off the advance as expected.
It sure chugs real hard when in gear so it does not seem like I lost compression suddenly. I still need to get my hands on a good compression gauge to verify each cylinder.
It seems like two adjacent injectors suddenly starts jamming. and suddenly run very lean with total misfires at idle and lean on load causing the pinging.
I will eventually boroscope all the cylinders as well.
Raptor,
When a cylinder is overhauled or repaired the surface of it's walls are honed with abrasive stones to produce a rough surface that will help wear the piston rings in. This roughing up of the surface is known as "cross-hatching". A cylinder wall that has been properly "cross hatched" has a series of minute peaks and valleys cut into its surface. The face or portion of the piston ring that interfaces with the cross hatched cylinder wall is tapered to allow only a small portion of the ring to contact the honed cylinder wall. When the engine is operated, the tapered portion of the face of the piston ring rubs against the coarse surface of the cylinder wall causing wear on both objects. At the point where the top of the peaks produced by the honing operation become smooth and the tapered portion of the piston ring wears flat break in has occurred.
---------- Post added at 08:29 PM ---------- Previous post was at 08:23 PM ----------
Something else to add I had a timing light on both cylinders monitoring the firing of the two plug and while doing so they seemed to firing evenly but occasionally started to have a rapid multiple fire effect. I have not looked at the others the same way yet. Have not been able to review the tech data on puter ignition control yet. So i am not sure if the puter is working over time to fire them.