Update- Pulled the intake manifold and the head off. Intake gaskt was in very bad shape, head gasket looked ok, definitely a difference in the way the valves looked, but couldn't find a problem with them sealing. replaced gaskets and re-installed. same problem still exists. Valve springs look fine, ...

not anti-seize, prolly just some gunk

plugs.jpg Pulled the valve cover and the plugs this morning, we replaced the double platinums with copper plugs a couple days ago (no change) and here are the #3 and #5 plugs respectively (3 on the left 5 on the right) the pushrods seemed worn, so we pulled 2 from the old motor, checked lengths etc...

I have a Castle oil cleaner I'll try- any other rec's are welcome though, and thanx to all for the help so far.....

wouldn't it make noise though? what's the best way to un-stick it? I can see the rocker arm through the oil fill, and its moving well, and when i had the manifold off it seemed to move well and comparable to the other intake valves while cranking.

compression between that cylinder and #5 are very similar at around 175-190, leakdown seems to be non-existent, that is the gauge holds pressure for quite awhile.

There's only one bank on this car, but STFT is between 0-4% at both idle and 2000 rpm and fluctuates rapidly

The misfire counts on my OTC genesys at low RPM, it stops counting @ about 1500-2000 RPM's swapped coils with another from same motor and no change in cyl#3, also changed injector with #5, still a problem with #3.

It shows 17-20 " of vacuum @ idle, and seems steady, can't find any vacuum leaks, had the intake back off again, and watched the valve moving while cranking over.. seems the same as any other valve.

there is injector pulse, verified with lab scope and i can hear it rattle, to be sure, I replaced the injector with one from the donor engine (twice just to be sure).

replaced the iggy module, the motor was from an '01 lesabre i think, was told its the same.. also did the crank sensor relearn procedure, no help there.... the car did not have any running issues before hand, but the bottom end bearings were shot. checked timing with a light on all cylinders, and it...

Did a motor swap on an '02 Bonneville 3800, got it all done, and have a misfire on cyl#3, with the occassional miss on #4, not too worried about 4, but it may be related. good compression, running and not, replaced coils and module and CMP, and CKP, from old motor, also wires and double platinum plu...