I would be looking closely at grounds as well as all connections especially your main switch.
The low voltage as well as the increase in poor running you have experienced certainly leans me in the direction of loose or poor contact.
Hopefully you get a resolve soon, Rich
I've seen cars do strange things when the earth is poor. As mentioned by @rich I would be taking off all the earths (and perhaps live connections), cleaning them and what they clamp to, with a wire brush.
Inconsistent voltages and slightly low voltages are an early sign of a simple connection issue. Incidentally I've seen that a reasonable voltage reading, does not mean that the right current can travel there too.
It's free (with regards to parts) to clean the connections, and as it is simple, sometimes it is overlooked. People always seem to gravitate towards component failure, but I believe the slight voltage drop is the real clue here.
I'd absolutely be doing this first, and then reverting back to the current train of thought as suggested by Dan.
To test the fuel pump why not jump the relay and turn the ignition on to log the data over a period?
Potential solution. Bad relay was causing second battery to not link with the main battery
update. Car is fixed. New engine runs well. Three issues found and corrected. I’ll fill in details tomorrow
The main problem was that the two batteries were unlinked, which caused drawdown in the main battery, also resulting in the charging system to be inoperable. I suspect this prevented the ECU from getting the power it needed to operate the injectors -- maybe something similar to what Dan had discovered/mentioned once with a bad starter that was causing a voltage/power drop.
The three problems:
1. Broken end of one of the spark plug wires at the coil side. This terminal is cylindrical but had broken, so only 180° of the terminal remained and did not make a good contact. But I don't think this was *the* problem.
2. The relay below which I believe is called a charging harness relay is a problem -- the tech (WISKO Racing) said it is suspect and inefficient.
3. This connection (back of firewall) was loose. I think this leads to the ECU.
So it is unclear what *the* problem was. I did notice many months ago at VIR that I felt this engine was down on power compared to another SR3 1500cc. Twice I got a great jump out of oak tree turn and the driver pointed me by, but I could not get by him on the long back straight until the driver lifted. So the spark may have been weak on that cylinder for a long time. This car only has 45 hours on it and it just goes to show you that anything can break on a race car at any time. I had a spin safe clutch burn out on the third day of use a couple weeks ago.
On a side note, WISKO Racing (Virginia Radical dealer) was amazing; the tech diagnosed and solved the problem in about 3 hours, and in that time he swapped a lot of parts. He did rule out the PDM and starter. I told him that I had ruled out the coil pack and wires, but he checked them anyway and found a problem. He was very thorough and found three separate problems which is astonishing. The new engine purrs like a kitten now. Very happy ending.
@davidf Glad you got it fixed and I'll echo your comments about the WISKO techs. When I first got my car it wouldn't shift out of neutral after the first day. They worked really late to figure out it was an ECU issue and got it running by the beginning of the next day.
