My 1970 302 originally a 2bbl will not idle. It will only run by holding about 2000 RPM. And then it sounds awful.
Now let me explain its history and what has been done. The car has at least 125,000 miles and may well be 225,000. It had a leaky water pump. So I changed it. While apart I did check the timing chain and marks, it looked OK. As old as it is it did run OK.
Then a few weeks later I discovered a large amount of coolant leaking from the intake manifold. When I bought the car it came with a brand new Edelbrock Performer RPM manifold and a 1406 carb. Although I planned to do that change later on, I decided that I might as well do that now to cure the leak.
So I went ahead with the installation. I has never run right since.
Here are the things I have done to correct this:
1, Removed and reinstalled the manifold twice using Felpro gaskets and changing to Mr. Gasket. I also added ARP studs on the last install.
2. Used 2 different distributors, the original and a brand new Pertronix. Reinstalled both multiple times.
3. The car has an MSD 6A. So I removed that. It was running fine with it before the manifold change.
4. Used a Holley 600CFM carb to replace the Edelbrock. Rebuilt both carbs.
5. Tried both the original and an electric fuel pump.
6. Tried 2 different fuel filters,
7. Tested for a vacuum leak and found nothing. This was hard to do at the 2000 + RPM.
8. Ran compression test. Although a cold test as it’s hard to get it warmed up. No cylinder is less than 155 and consistent 155-160 across all.
I’m suspicious of the plug wires. They are MSD and were on the car when I got it 2 years ago. I once had a car that I put brand new Accel wires on and it had a high speed miss. One night I opened the hood before I turned on the garage light. The wires were like a light show. Replaced them with Taylor wires and never had an issue in the 16 years I kept that car.
Just a word about my own background, I’ve been working on cars for over 50 years and have never encountered anything like this.
So I’m at a loss what to try next. So I’m open to suggestions.
Thanks in advance
