I had a list of things to do last night, but I did basically none of them, other than finding the giant wiring diagram in the packet of papers that came with the car.
I want to go about getting the fans set up to run to prevent overheating and work out what wires are for the headlights so I can have those ready. But I got distracted from that pretty quickly in my quest to try to make sure the ignition timing is set correctly. Because the timing marks are on the flywheel (!) I decided I wanted to try to set the timing via vacuum readings. When I popped the vacuum line off the fuel pressure regulator, though, I got a steady stream of fuel. Bad fuel pressure regulator. This failure mode is interesting to me because it holds a vacuum with no problem, but it still will suck fuel through the diaphragm.
I had already switched to the spare regulator, so I first tried re-sealing the original one with fuel-safe RTV, but that wasn’t the problem with it. The membrane itself was porous and allowing air to pass through. So I needed another membrane.
Nitrile rubber is fuel resistant and I just happened to have an old nitrile glove hanging about in the trash. Originally, I wanted to completely replace that membrane, but I couldn’t figure out how to remove that center bit. I tried to press it out, I tried turning it, but nothing seemed to be working. So I went to the air side of the housing, put the spring in, and stretched the glove over it.
I dropped the failed membrane on top of the glove, added the fuel-side half of the regulator housing, and put the screws through.
Installed back on the car to test and no more fuel leaking through the regulator!
I’ll clean up the glove and bolt it down later.
That problem solved, it was still running rich. Before making an attempt at tearing down the carburetor, I remembered hearing that the main cause of carb rebuilds was timing, so I went back to my original task of setting the timing. I put the car up on the lift, hooked up the timing light, and peeked underneath. As expected, the little marks on the flywheel were basically impossible to read, so I put a little white mark at the 15 degree line with my paint pen.
There’s supposed to be a plastic cover over that with a small inspection window and an arrow smack in the middle of the car that indicates where one is to read the timing. While I do have that cover, it is not attached to the car and, frankly, I’m not entirely sure how it’s supposed to be installed with the subframe and the steering rack in place. Add that to the list of “problems for later”.
At any rate, with the timing mark now visible, I got the distributor twisted around to put the timing at the specification of 15 degrees BDC plus or minus 2 degrees. I was hoping that would clear up the richness, but it is still pushing a little much fuel. The upside, however, is that it is running really smoothly. There’s no bogging down at load on throttle at all and it just idles beautifully. I have no way of checking fuel pressure right now, but I suppose the only thing that could be causing the issue other than the carb needing to be rebuilt is if that little seal on the regulator is leaking, preventing it from sealing up the flow.
With all the other rubber seal problems I’m having, though, I think the simple answer is that the carb just needs some love.
On a smaller note, I did determine that the temp gauge in the cluster is operational. I don’t know how accurate it is, but as the car idled, the gauge came up and started to move. The boost gauge remains non-functional as I need to find the hose that provides its signal and get it hooked up. There is also another coolant leak – this time it’s the lower end of the rubber hose that goes between the engine and the metal coolant pipe to the bottom of the radiator. It’s a pretty minor leak, but still should be addressed since it might become less minor when the system is at full pressure! I’m going to attempt to put another hose clamp on it to see if it will seal up that way. If that doesn’t work, it’s a pretty simple elbow that I may have laying about or at least won’t be tremendously expensive or hard to find.