it cranks the same way when attached. I was in the process of pulling the dist. cap again to check for play in the shaft and gear.

 

I have not seen it but can an ICM send a bad signal so it still gives spark just not in the right timing with the compression tdc? or would that be more crank sensor?

 

The crankshaft sensor sends a pulse signal to the PCM. The PCM calculates how much ignition advance is necessary and sends a ground pulse to the ignition module that includes ignition advance. The ignition module sends a pulsed ground to the ignition coil to fire it.

Crank sensors can and do mess up, however, they either become erratic or totally fail. In either case, a DTC will be set in memory and the SES light will come on. The same holds true with the ignition module, but it may or may not set a DTC in memory, just depends what the problem is with it.

In your video, kinda hard to tell for sure, but it almost sounds like timing might be retarded.... are you seeing P1345 in memory? Is the SES light on? How many miles on the engine?

 

189000 miles and the only code it tripped the last time it ran was a p0300. I was thinking of going to the junk yard tomorrow and getting an ecm.
it sounds like a timing issue to me too and the ecm is all that is left. I have spark, fuel and compression. last night I changed the cap and rotor and as thought. it made no change
I have also noticed what ever the fault is, it is changing because last night it wouldn't even hit like it previously was.

 

I know ecm's need to be flashed, but if I get one off a running vehicle shouldn't I just have to change out the EPROM inside to transfer the vin information?

 

I picked up an ecm off a 2000 blazer and did the anti theft relearn and still the same problem.<br />
so let me recap on the scantool I am reading 300rpm while cranking so I believe the ckp sensor is OK<br />
I have spark at each plug<br />
my distributor is pointing at the 6 when the crank is lines up properly with the block markings<br />
fuel pressure leak down jumps to 62 when activated and drops to 52 and holding after 10 minutes<br />
compression between 175 and 205 on 5 of the 6 cylinders (I have not checked the one behind the steering column) but it should start on 5 and run horribly.
and there are no DTC present.
I dont know what is left.

 

The new PCM does not have an EPROM. It does need to be flashed to your VIN. Each crankshaft position sensor is unique, so the crankshaft position sensor relearn must be done along with the flash. If it's not done, the PCM will use the data from the last relearn, which is not accurate with your sensor. The engine should at least start and run, but all PCM calculations & adjustments to ignition timing, fuel injector timing, injector pulse width, EGR, etc etc will not be accurate. The flash & relearn should be done before continuing with the diagnosis.

 

So after another week and frustration I replaced the coil even though I had spark at the plugs and that fixed the issue. I rechecked the measurements and the secondary was measuring 5,650 Ohms and the spec was 6,000. Very small difference, but under compression it was just not enough to give a complete burn.

Now I have it running, but it is low on power and sounds quite compared to before. I think the Cat got damaged from the unburned fuel driving it home that mile when it failed.

Lesson learned, if the spec if out regardless of how small, replace it.