Ten Steps To Revive A Barn Find 1977 Porsche 911S In One Day
How much work could an old CIS system really need to work again?
My friend Manuel has dragged a 1977 911S out of a 15-year hibernation and is documenting the process over on Rennlist.com. This car has sentimental value as his father purchased it brand new, and it was the chariot that brought him home from the hospital when he was born. It's in rough shape, but he's aiming to get the car back to road-worthy later this year. He is perhaps not the most mechanically savvy people, so when it came time to get the engine running again, I volunteered my services. Perhaps a bit on the overconfident side, I promised that I could get it to run with just one day of work. Manuel mocked my hubris but was eager for the help, so I hopped in the car and drove the 9 hours from Reno to Los Angeles to give him the helping hand he needed.
Here are the steps we took in the attempts to get it running again.
1. Take stock of the engine's condition
Thankfully, before I'd even arrived, the car had been towed to the Haynes Manuals (yes, the one you're thinking) facility, and the engine had already been given a once-over. The engine was actually hydrolocked with oil leaked into one of the cylinders, so all of the spark plugs were removed and the oil was drained out. From there, the engine turned over freely, so we at least knew it everything was intact. A borescope helped determine that the insides of the cylinders were all clean and clear of corrosion or debris. That's a good sign.
In any engine, the goal is to mix fuel with air and use a spark to ignite it. If you have those three things in the proper order, you'll have a running engine.
2. Check the fuel pump
The first thing I checked on was fuel, as it's the easiest to get wrong. With the key turned to the on position, the fuel pump should make noise, just long enough to prime the system. In our case, that didn't happen, and as we would find out, it happened for two reasons. I removed the pump from the underside of the front trunk floor and bench tested it by putting a battery jump box directly to its terminals. There was no noise, even with direct power, so we had a dead fuel pump. Luckily a local automotive chain store had one handy for us to pick up that afternoon.
3. Check the ignition system
Following air, spark is the next important thing to check. You can easily test the plug operation by holding the igniting end of your spark plug up to something that conducts and cranking the engine over. If the plug provides a nice clean spark, you know your ignition coil, distributor, and plug wires are in good enough condition to run. Do that to all six of your plug wires and you'll know whether that engine is going to fire up or not.
4. Test the engine's compression
Compression should be tested when the engine is up to operating temperature, but running a preliminary test on a dead engine is an easy way to determine if you've got a bad cylinder. The numbers themselves can't really be compared to another engine, even of the same type, but rather are more for comparison among the six cylinders. In this case, the number 3 cylinder is a little on the low side, but not enough to be concerned with, especially for an engine with 160,000 miles on it.
5. Check the fuel tank
The fact of this car is that it has been sitting in a garage for 15 years, unfortunately with most of a tank of fuel. I was concerned about rust, so I pulled the fuel level sending unit out of the tank. That was the first indication that everything had gone pear shaped. Fuel has a tendency to break down over time and in the case of this Porsche, it had become seriously 'varnished'. The sending unit had essentially disintegrated over the years, and there was a thick coat of clay-like sludge in the bottom of the tank. Yep, time to remove the tank.
6. Check the fuel lines
With the bottom of the tank coated in sloppy goo, the worry was that the same would be true of the fuel lines. By disconnecting the line from the CIS fuel distributor block in the engine compartment and blowing several blasts of high-pressure air through the line, I was able to get this gunk to come out of the fuel line like it was a flu-addled child with a handkerchief.
7. Install the new fuel pump
This is pretty self-explanatory. The new pump arrived at the store at 2 PM, so we went to go pick it up and popped it back into place. Of course, in hauling the old fuel tank out of the car, I had broken the ancient rubber fuel pump mounts, requiring zip ties for temporary installation. The new pump was a cheap Chinese knockoff, but it would do the trick for the time being. I advised my friend to have his original fuel pump sent out for rebuild, and to keep the reproduction pump on a shelf for a backup if necessary.
8. Rig up a temporary fuel system
This isn't exactly recommended as it's more likely to be something those numbskulls over at Roadkill would attempt, but desperate times call for desperate measures. Without a fuel tank, we had to improvise a bit. A catch can system for the fuel return line ended up being an oil pan sitting on the floor. A length of plastic hose zip tied to the fuel inlet served as a stand-in for the traditional pickup line, now unceremoniously dunked into a 5-gallon plastic fuel can. The fuel pump still would not click on with the key to prime the system, likely a fuel pump relay problem. In order to get the fuel pump to push fuel, I simply wired it directly to the 12V battery jump box. Don't worry, we had a fire extinguisher nearby just in case.
9. Fire it up
The engine tested good, and the ignition system is fully functional. We have a temporary system that will deliver fuel to the engine in a pinch. It's ready to run for the first time in 15 years. Crank the key and let it rip. Manuel, would you like to do the honors?
We didn't have a bottle of champagne to pop, but our emotions were running at full bore. In just ten hours, we managed to take a big hunk of Porsche-shaped metal and revived it from 15 years of slumber. Because this car means so much to Manuel and his evolution as a car guy, it has a story to tell, and I'm proud to have been a part of that storytelling process. I can't wait to see this car on the road once more.
It only took 10 hours of wrenching. I was right, I had it running in just one day.
Thanks to Manuel for trusting me to help him on this project. Thanks to Patrick Stevenson for capturing the glorious moment on film. Thanks to Haynes for giving us space and tools to get the job done. Thanks to Porsche for building a rad machine capable of sitting for 15 years without too much detriment. To read more about this project, go check out Manuel's depiction of the project on Rennlist.com.