Porsche 914 - Engine Problems

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Richard914
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Porsche 914 - Engine Problems

Post by Richard914 » Thu Jul 05, 2018 3:25 am

Hi All,

I'm just starting to re-commission my 914 2.0 lt (carbs) which has been sitting in the garage for many years (I'm an amateur with almost no mechanical experience but am wanting to learn).

Over the years the car has been turned over but hasn't been on any long runs and the fuel level wasn't high (recipe for disaster!).

When the car is on the flat the engine runs fine but doesn't seem to have too much power but, when going up an incline it starts to make rattling noise and the steeper the incline the rattle gets much worse, then it looses power then stalls (sounds like shaking a tin of nails - not sure if this is pinking?). After leaving it a minute or so the engine fires up and runs okay again.

Before taking it into a garage, I wondered if the following would be a good approach to finding out what the problem(s) are:

a. Change the fuel filter
b. Add Redex and a lead replacement additive to the fuel
b. Take the car for some long runs on the flat

Any advice on what the problem may be or next steps (for an amateur) would be much appreciated.

Thanks in advance.

Kind regards,

Richard

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raygreenwood
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Re: Porsche 914 - Engine Problems

Post by raygreenwood » Thu Jul 05, 2018 2:18 pm

Drain the fuel tank. Typically they get silted up...rust, additives and condensation. There is usually a sock filter inside of the tank that gets plugged up when the angle is right. Turning the engine off lets the back flow of fuel rinse away a small amount of the silt so it runs again.

You can see the strainer diagram at this link. The strainer is item # 10 on the 1973 fuel tank diagram and item #11 on the 1974 diagram.
http://www.autoatlanta.com/porsche-part ... _parts.php

Personally I remove the in tank strainers...clean and de-rust teh tank and put on a EXTERNAL strainer between tank and fuel filter. There is nothing worse than getting stranded in teh middle of nowhere and having to drain out and/or lose all of your fuel getting the stupid in tank strainer out.

This can also be poor float level adjustment in the carbs. I am assuming twin carbs because noted "carbs"...and not the dreaded center mounted two barrel "door stop" carburetor.

Putting additives in old fuel will not help. Over a long period of time...what evaporates or oxidizes out of the fuel is not replaceable. Fuel stabilizers only prevent this oxidization loss. They do not replace what is lost once its gone. Also...lead additive is not necessary. Other than an octane issue which a stock 2.0 should not have with premium....these engines had nickel alloy valve seats and did not require lead as a lubricant.

Ray

Richard914
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Re: Porsche 914 - Engine Problems

Post by Richard914 » Fri Jul 06, 2018 4:29 am

Hi Ray,

Thank you for you advice, it all make sense and is gratefully received.

As you've suggested, I will attempt to remove and clean the fuel tank first. It's my first major (for me) job on the (a) car, so it might take me a while!

Yes, the car has twin carbs (was originally fuel injection -1975). I wouldn't even no where to start regarding the float level adjustment.

Thanks again.

Kind regards,

Richard

Richard914
Posts: 7
Joined: Mon Jul 02, 2018 12:53 pm

Re: Porsche 914 - Engine Problems

Post by Richard914 » Sun Jul 08, 2018 7:03 am

Hi Ray et al,

Here's a picture of the fuel pump and fuel filter under the fuel tank. Can anybody tell me what the silver object to the left of the pump is (could it be a external strainer, as Ray has mentioned above or an additional fuel filter)?

Also, before removing the fuel tank I'm going to purchase a length of fuel hose, can anybody tell me what diameter I would need?

Thanks in advance.

Kind regards,

Richard
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raygreenwood
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Re: Porsche 914 - Engine Problems

Post by raygreenwood » Tue Jul 10, 2018 5:45 pm

That silver item is a fuel filter. So is the square white thing in the back ground.
On this system unless you are using a specific filter...both of those filters in your picture are designed to be on the low pressure side of the fuel pump between fuel tank and pump. You do not need both of them.

I have no idea what pump you have on there so I do not know the inlet and outlet size. The 2.0 never came with carbs. It was fuel injection. And....it did not use that type of pump. Some better picture of the pump may help. Ray

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sideshow
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Re: Porsche 914 - Engine Problems

Post by sideshow » Tue Jul 10, 2018 9:23 pm

If that is the Carter pump that many sell, its 5/16 or 8mm, the square one looks like OEM a t-4 to vanagon era. Audit what have to connect to, likely they were chosen as adapters also. No matter the origin I suggest measure it yourself before asking keyboard experts. Running multiple prefilters does little harm unless it restricted flow, or leaks...simple seems to work best.
Yeah some may call it overkill, but you can't have too much overkill.

Richard914
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Re: Porsche 914 - Engine Problems

Post by Richard914 » Wed Jul 11, 2018 10:42 am

Hi Guys, thank you very much, all noted and understood. I'm planning to start working on removing the fuel tank this weekend and will report back on how I get on. Thanks again. Kind regards, Richard

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