Deep freeze to drive: Part two out of three
Q – OK, my 1974 Porsche 914 is running again! Thanks for the advice. Now what else should I plan for as I venture out on the highway? Oh, and it still blows black smoke! So where do I go with this old relic from the seventies? I know a lot of people have ditched the fuel injection and gone with carburetors. –Pete
A – Well I said we would talk about brakes and such but since you asked, here are some tidbits about the fuel injection on your car. Since it was designed in the fifties and sixties, it was state of the art…fifty years ago! And I admit it is tempting to convert to carburetors but hold on, start with the basics. Now that you have it running, are the ignition points set correctly? Do the wiring terminals in the engine compartment (or in the car in general) have good integrity? Are all the ground wires intact and solid? That’s where I would start.
With the ignition system intact, good compression and solid electrical connections, next you need to check fuel system pressure. Fuel pressure gauges are inexpensive and if you assume that you have proper pressure without testing, you can waste hours chasing your tail.
The next area to investigate is the intake system. After 40 years, some of the hoses and tubing in the engine compartment become brittle and leak intake vacuum. On the early D-Jetronic FI system, the design fails safe when vacuum hoses leak and the fuel system will go rich (too much fuel) but the car will usually still run. On the later L-Jetronic systems, intake vacuum leaks will cause the engine to run lean (too little fuel). In that instance, a common “do it yourself” tactic is to richen the fuel mixture up so that the car will not stall. That only works up to a point. Obviously tampering with fuel mixture without diagnosis is a “Band Aid”, not a cure.
There are two ways to ensure intake system. There is the shotgun approach where you replace every hose in the engine compartment, also known as “firing the parts cannon”. I recommend a targeted method which involves introducing smoke under light pressure to actually locate the leaks. Some leaks that I have seen were completely hidden from the naked eye and could only be found that way. I practically guarantee that you will find leaks using this method. Every incremental improvement to these systems will improve performance and fuel economy.
So we will assume that you have the car purring again and after your “pre-flight” check list, you may be ready for a trip around the block. Before you do though, evaluate the brakes. How does the pedal feel? Is it hard, soft, or can you push it all the way to the floor? When you release the brake pedal, does it return normally?
Cars that sit around tend to get stiff in places you might not notice immediately, such as the pedal cluster bushings, shafts, and springs. Jack the car up and have your assistant push on the brakes as you rotate the wheels. Naturally, the wheels should stop but just as important, they should release when you stop pressing the pedal. If the wheels won’t turn after you release the pedal, only a short trip around the block will be possible, if that! Often cars that are pulled out of storage will have a remarkably solid brake pedal due to sticking brakes but one hard stop from 60 mph will cause them to get harder and harder but barely stop the car. For that reason, you shouldn’t make your first test drive a fast one…neighborhood cruising is a good way to evaluate such things, and safer than a highway shake-down to start with.
Once you get that test drive done, and you are grinning from ear to ear, plan to set aside a weekend to go through the brakes. Even if they work well initially, you can not trust old parts on cars that have been sitting around for years. Parts I would always plan to replace are rubber brake hoses, master cylinder, brake caliper repair kits, front wheel seals, brake pads and in many 914s, remanufactured rear brake calipers. The majority of the system is uncomplicated and easily serviced by the average motorhead but the rear calipers are not. They have a hand brake mechanism that is best left to a pro.
If you take the time and prep the parts well, take just a little more time to apply some paint to the calipers and rotor hats for appearance and resistance to rust. I prefer zinc cold galvanizing compound followed by primer sealer then a paint color of your choice. Remember when servicing the brake system, wear safety goggles since brake fluid in the eyes can do some damage. MC
Q – I have been reading about the direct oil feed for my Porsche IMS bearing issue and I wonder what you think of the idea. If I do that, would you consider it an alternative to replacing the bearing or should I do that too?
A – I have to admit, I love the concept and endorse the product. Based on all the speculation about the cause of the problem, my personal opinion is that a source of constant lubrication for even the stock bearing would give me all the peace of mind I would need. Naturally when the bearing is out, a value judgment can be made and if needed, the bearing replaced as well. Consider it “belt and suspenders” as my dear friend Andy says. I would also consider the direct oil feed an improvement not only functionally but also as a selling point if you choose to sell the car. MC
So for this installment, if your luck holds, you will have the car running again and after a “pre-flight” check list, you may be ready for a trip around the block. Next time, we will talk about tires, bearings, steering and suspension. MC
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Next time, we will talk about brakes, tires, bearings, steering and suspension. MC