So I have been restoring my 85 rx7 that has around 70k miles over the last couple of years after sitting for several. I did everything in FAQ page (eg changing the oil, plugs, filter, antifreeze, drained the fuel, changed the fuel filter etc.) Last fall I changed out the catalytic converter, as the first or 2nd converters were getting red hot and I figured the cat was plugged (which I think it was, as it was original). Before I put it away last winter, the red glowing problem had moved to the cat, so I figured further down the line was plugged, so I just replaced the muffler this spring. The situation is, I can get the car to start and run with the choke on until it reaches temperature. when the choke temp sensor pulls it in, the car dies. At that point with the car up to temperature the only way to get it to run is to pump the gas and when I do that the cat converter will get red hot again, so i am assuming that unburned fuel is getting into the cat and then igniting. I watched the pipes underneath and they do not get read hot during the warm up period, but only when I pump excess fuel into the carburetor to keep it running. I also noticed that the caburetor is now starting the get dirty again, after cleaning with carb cleaner. I have not been running it for long as I don't want to do any severe damage. So I am basically looking for advice here. Do I start with the timing, fuel mixture, idle speed, or all the above? Any advice where to start? thanks in advance.

 

It sounds like you have lost your leading ignition, which will cause overheating of the exhaust system. See if you have spark on the bottom plugs...







.

 

thanks, I will give that a try tonight and let you know what I discover

 

so i pulled the plugs, all four appear to be fouled, the bottom front plug has some scorching on one corner. I am running NGKs as recommended. All four plugs have spark in an alternating pattern. maybe in my cleaning of the carb and not being able to bring it up to temperature last year due to the cat, etc, I fouled the plugs. I will get some new ones and see how it runs. I guess I should have checked this thanks