Darksteel

I thought checking the compression would show if the gasket is good? Yeah, the temp has been steady and the same as before it overheated during the few times I have driven it.

I have attached the pictures of the oily spark plugs (they are a pretty nasty). Those are from cylinder 1 and 2 but the rest look about the same. I also my have found the problem... I randomly unplugged the AFM plug to check the contacts and noticed it was a little loose. After looking at the contacts, the socket that goes to pin 27 on the AFM was pushed down inside the plastic housing. So I'm not sure if it have been making contact. Pin 27 is part of the air temp sensor circuit. I think the plug was jostled when I removed the air filter to get to the last bolt holding the old radiator on. We'll see how it runs after I take care of the last few things.

I forgot to respond to this, but I'm not sure what you mean; could you explain it a little more? I have already checked a lot of the electrical connections under the hood, but I'll go through them again. Hmmm, I didn't know overfilling the oil pan could cause those problems. I'll drain the oil soon. And I'll take some pictures of the spark plugs tonight when I get home from work.

Oh, I forgot to mention that. I did check the water temp sensor from the ECU plug; although I only checked it when it was intalled in the car with ambient air temperature. The resistance reading corresponded to the ambient air temperature from the EFI manual. I'll go through the rest of the EFI manual next. Could the overheating have damaged the water temp sensor such that it reads incorrectly at higher temperatures? When the car is cold the water temp sensor reads correctly, but when the coolant reaches a certain temperature, the sensor isn't reading it correctly? Just a thought I had when reading your comment.

So I have a bizarre problem and I'm not sure what to check. Let me start at the beginning. I was driving my 1976 280z and noticed the temp gage all the way to the right so I pull over soon as I can. When I look under the hood there is coolant squirting out a hole in the front of the radiator. After I tow the car home, I drain the oil and it doesn't look like any coolant has gotten in. I drain the coolant and it doesn't look there is any oil in the coolant. Then I install the 3 row radiator from MSA and add fresh coolant and oil. (I accidentally put in too much oil, so the level is at the left "leg" of the H.) I have only driven it a couple of times since then, because it has been acting strange. Here are my observations: -When I start the car cold, it runs fine -After driving for 10-15 minutes, it starts running rough and loses power -Here is what I mean by running rough: -The exhaust makes a "chugging" noise; puffs of air come out of the exhaust -The car shakes a lot more that it has before -When I shut the car off, and start it a short time (30-60 mins) after that, it will still run rough It seems like it runs rough only after it has reached operating temperature, but I don't know for sure. Here is what I have done: -Checked the ignition to make sure the spark plugs are firing. They are firing. -Checked the vaccum advance on the distributor. It still advances the timing. -Checked the compression in each cylinder. The compressions were decent, 160-175 for all cylinders. -When I checked this, I noticed that all of the spark plugs have wet oil around the outside ring of the spark plug. I haven't check the fuel pressure yet. At this point I'm not really sure what is wrong. Anyone have any ideas of what could be causing this? Any help would be apprciated.