Do you have the obd port? Might want to check for codes that way. If no codes you may be able to see something in the readings. When you hooked up the fuel pressure gauge did you drive it around with it hooked up? Pressure reading may have been fine at idle but may drop when driving.

 

Just pull the valve cover off and watch the way the cam and valves act while the engine is running. I often use my adjustable timing light to "freeze" the motion. With the retard **** (not all lights have this) you can move the frozen scene.

I'm surprised you're still running the cat. on your exhaust. Back when I ran a shop, we got a gorgeous 1964 Buick convertible in. This was around 1981 or so. The owner had taken it to several shops and two dealers to find out why it ran okay most of the time but when you got on it, it fell on it's face. The car only had around 16,000 miles on it and it looked new. I worked cheap so it was left while I tinkered on it. I eventually removed the hood and propped my vacuum gauge (the one in my photo) on a block of wood taped to the air cleaner. I went out on the expressway and drove a bit. Nothing happened until I floored it. The gauge was reading a steady 15-17 inches depending on throttle position but when I floored it, it dropped to 4 or 5. I limped back to the shop and kept the car running until we could raise it on a rack. I used a hole saw to cut the Y pipe. I got a release of high pressure and the engine smoothed out.

I called the owner and told him I found the problem. It seems Buick being a premier brand used a double walled pipe to reduce noise. Since the car was only driven occasionally and never very far, it had rusted inside. A flap of metal would flip up under heavy throttle would close things down. I had called a friend with an exhaust shop and set the owner an appointment for a new exhaust. Total cost for the exhaust and my shop time was around $200 in 1981 dollars. He was both elated to get his car back and working and pissed that he had spent nearly $800 at supposed professional shops and a salvage yard with a repair shop on the side fixed it.

I managed to listen to you knocking on the cat. on your car. It's not rusted but the medium inside might be melted. I suspect that is what is causing the flutter. If the track requires a cat. converter to rce, I'd put a low restriction unit on the car. Otherwise just run a straight pipe.

 

No, there isn't a OBD port on this car. But interesting though, when I attached the vacum gauge, i just tested it at idle, I'll try it again and rev it up and see if anything changes.

 

Okay, so I just pulled up the rules, and I can remove my CAT. I'll cut it out tonight. I'll let you now how it goes. I'll also check the compression on it too. I appreciate y'alls help!

 

If they don't require a muffler, remove that too. Pure flowing after that. Although you'll want to run the pipe out the back for safety. CO is nasty stuff. Also wrap the pipe with header wrap to keep the floor cooler and reduce fatigue.

 

Okay, so I just did the compression test, I'm struggling to find a cylinder diagram, so I'll just add pictures. Looking at it from the left side, the 1st 2 cylinders read 120, the next 2 read just at and just below 90. Is this normal?

 

That's not good. For cylinders to be mismatched by a little is normal. With the odd vacuum readings, I think you may have a problem with cylinders #3 and 4. (Passenger to drivers side is 1,2,3,4) I suspect a blown head gasket. You have probably one of the easiest modern engines to repair a blown gasket, but the head will need to come off. Before we condemn it, pop the cat off and see what happens.

 

The 2.2's where known for bad head gaskets. Fel pro time.

 

I like to make sure it isn't something else first. On the other hand, the 4 banger he has is probably the easiest engine since flat heads went away to fix a head gasket.

 

The turbo versions are not! I disconnected the turbo and removed the head. Not easy but it can be done. Do a leak down test, That will tell you for sure.