The fuel system. I'm tackling the whole system instead of going bit by bit. At the front, the tank is clean inside and draining the gas doesn't reveal any particulates so there's no need to pull and clean/seal it. Jumping the fuel pump relay terminals doesn't make the pump run, so in goes a cheap replacement pump (bad idea, I'll explain later).
Next up the injectors are trashed, so they're replaced with new Bosch units including seals. From here, I top it off with a new fuel filter and it's starting and running, but it's not wanting to take any throttle. Pressure testing the system, I discover the plunger in the Fuel Distributor is stuck open allowing a constant flow of fuel with the pump on. Pulling and cleaning it along with the WUR (Warm Up Regulator) and I'm in business!
The only issue now, is that once the engine was warmed up it won't start. There are two possible causes: either the check valve in the fuel pump is faulty (remember that cheap pump?), or the Fuel Accumulator is bad. I go for a new accumulator since I just replaced the pump... no luck.
Next is a straight exchange of the pump... and it works! (UPDATE: The cheap fuel pump lasted 4 months, I replaced it with an OEM Bosch unit.) Now it easily starts when warmed up. It’s not perfect, but it has really good power now, and it’s actually really fun to drive. I do need to do some diagnosing on the oil and air cooling system now. It’ll drive for about 30 minutes at a time before it starts running hotter than it should. There are 2 thermostats in the oil system I have to test, and I need to replace the fan belt (it’s loose), and I’ll also blow compressed air through the cylinder head fins in case there’s any debris in there.
Porsche 911SC First Drive
Porsche 911SC at Speed