Did a compression test this afternoon. All the cylinders has good compression. So now I'm at a loss as to what the problem could be. Could it be the PCM? I disconnected the battery the weekend before this all started. Do I need to do the memory restore or whatever it's called? Number 4 cylinder has spark, gas, and compression. I have no idea what is going on. Anyone have any suggestions?

 

OK, you said plug #4 was soaked in gas, so we can safely assume it's getting gas in the cylinder. I assume all the other plugs appeared normal?
How did you check for spark?
Right now, I'm wondering if plug #4 is bad and NOT firing. Simple thing to try, replace the plug OR swap the plug with another one and see what happens. The next thing I wonder is that coil pack may have a faulty tower on it. Could try swapping the two plug wires that connect to it and see what happens.

Right now, the info you provided is leading me to believe cylinder #4 is NOT firing. I think that is the next thing to explore.

 

I replaced plug number 4 with a brand new plug, and still got the same result. I also put the loose plug in the end of the wire and held it against the exhaust manifold and had my son turn the car over. With the plug grounded against the manifold, I was able to see the spark at the plug. I had checked the voltage on the coil and it was where it should be. I'm assuming by the fact that I had spark at #4, that the coil pack is good?

 

That sounds logical to me. The only other reason I could think that the plug would be covered in gas and the others aren't is perhaps that injector is staying open.

I believe the GM Tech II scan tool has the ability to turn off one injector at a time (on a 3100/3400, that's SUPER nice since the upper intake has to be removed to work on the injector wires).

Is your Monte a 3800 or 3400? I'm making the assumption 3400?

Depending on how much work you want to put into it, you could try moving the #4 injector to a different cylinder (the goal is to see if now another plug is getting a bath in gas, if so, it's safe to say it's a bad injector).

 

Okay, here’s where I’m at...

I switched the plug wires on #4 and #6. Same issue (P0304).

I switched the 1&4 coil with the 3&6 coil. Same issue (P0304).

I switched the #4 and #6 injector. At first I was getting a P0300. Then I realized that the #1 injector had gotten pulled out of the injector port a wee bit. I pushed it back in as far as I could, but it still seems like it’s not in all the way. After I cleared out the P0300 code, I started the car and let it run again for about 15 minutes. As of now, there are no codes showing up. Still knocking, but there are no codes (at the moment).

I’ll need to put a new upper intake manifold gasket on it, so I’ll push that injector all the way in then.

 

BTW - Once you are done messing with the injectors, replace any O-rings that are on the sides you popped them out of. The O-rings are cheap and if the car has some age, it's worth having brand new O-Rings. Heck, if you have an injector not seating properly, perhaps that is related to the entire problem.

I might be reading too many threads of engine problems, but I did not recall you mentioning a "knocking noise". Do you know approximately where that noise is coming from?

 

I'm not sure where the noise is coming from. I used a stethescope to try and locate it. You can hear it pretty much everywhere in the engine. I'm going to give it a good oil change this weekend and use an engine cleaner as well as an engine treatment when I do the oil change.

 

I went home over lunch and ran the car some more. I got a P0300 code on it now. I'm thinking that I won't get too worked up about it until I can get the injector(s) seated right and a new upper intake maifold gasket put on.

 

I put a new upper intake manifold gasket on the car and made sure that all the injectors were seated where they should be. I started the car and I'm still getting the P0304 code when the car is running. After I shut the car off and check the code again, it gives a P0300. I'm VERY confused. I've checked all the ignition and fuel components that I know of. I'm really wondering if the cat is plugged and causing these issues.

 

Random multiple misfires can be any problem with the fuel system, could be a poorly operating pump not giving enough fuel, a clogged fuel filter, etc.

Your car running lean can cause the symptoms of the misfire.