94 Buick LeSabre misfires

[Alpha One]

My 94 Buick LeSabre misfires almost constantly on cylinder 6, but it also
misfires a lot on 5 and some on 3. I get only error 300.

I replaced the spark plugs and wires and it does the same thing.

I have the Actron ScanTool that tells me what the car is doing and during the same space in time 1,2,3 and 4 is firing while 6 is not. Sometimes 5 and 6 are not firing or, less often, 3 doesn't fire.

Also, if I connect a timing light to each spark plug wire while the engine
is running I see how often the strobe light doesn't flash. 6 is the worst,
then 5, number 2 I thing does it less or almost never.

The misfiring happens randomly.

The Crankshaft sensor was replaced 30,000 or 40000 miles ago. Do you think it could be the Ignition Module?

Antonio

[Alpha One]

I have new information on my 94 LeSabre. I replaced the wires and spark plugs. I also replaced the Ignition Module and Coils with ones from another LeSabre that works fine. I switched the injector 4 and 6 with the 1 and 3. Fuel pressure is normal. The same cylinders as before keep misfireing. In my other message I said the worse two where 5 and 6 but I should have said 4 and 6. In any case 4 and 6 were the worst and they still are. 6 misfires almost every single time. Any idea what may be causing this? Could it be the ECM?

Antonio

[Alpha One]

From bad to worst. This morning the engine was running as yesterday,
misfiring but running. I started the engine to check it again with my
ScanTool. A few minutes later it stalled and didn't start again. I have the original Computer that went bad maybe 2 or 3 years ago. The engine worked rough with it but worked; I tryed it before yesterday and the engine started and run.

So, gessing that maybe the Computer went bad (I had boght it used) I
replaced with the original I had from before, but the car didn't start
either. So I am assuming that its not the Computer but I have no idea what to look for next.

I checked, again, the fuel pressure, for spark in the spark plugs, for
disconected vacum hoses. Fuel pressure is about 42 psi, there is spark, and I didn't see signs of vacum leaks.

Trying to fix this non-start condition I replaced the Crankshuft Sensor and the Camshaft Sensor. Nothing!

When it stalled there were no noises or anything else, it just stoped
running.

Could it have anything to do with the scurity system?