Fuel Pump Problems

[Alex 67]

I posted a thread regarding oil coming out of my crank case breather hose a while back and I finally have found the potential problem. 1 of 2 1. Fuel pump problem. Fuel seems to be in the crank case and a friend said it might be due to a faulty fuel pump. 2. My car also had a bursch stinger exhaust on it so there was less restriction so the timing needed to be changed but it did not help so at a idle I stalled so I was always pumping the accelerator so this also might have flooded the carbs again resulting in the fuel in the crank case then the excces leaking from the the breather hose. Is this at all posible. I purchased an original exhaust from Scott McLean. Thank you Scott I hope this solves the problem rather than buying a new fuel pump.

[ScotMcLean]

Hi Alex - Glad you can put the 67 912 parts to good use! I'm always looking for 69 parts

Have you had a chance to pull the fuel pump & take it apart (carefully)? This will give you a better idea of whether it's time for a rebuild or maybe Josh912 could tell you more about how he skipped the mechanical pump and installed an electric one.

Just a thought - Scott, 69 & 76 912/E

[Green 912]

Gas in the oil has 2 common sources.

(1) A carb float will flood and “sink”, it will stick or the float valve will get something jammed in it. This will cause the carb to puke the excess gas into the intake making the car run real rich. This will cause the oil to just smell of gas more than fill the case.

(2) The mechanical fuel pump will leak right into the case. If this is the case stop driving the car and rebuild the fuel pump or replace it with electric unit! Gas in the oil is WAY bad for the motor. It will dilute the oil and accelerate all kinds of motor wear. Disassembly and rebuilding is easy to do and the rebuild kits are inexpensive. Change the oil and then change it again a week later after driving it some and making sure that you have fixed the problem.

If you want to replace the stock pump with electric you need to remove the mech pump and block off the hole in the case. Using the gasket as a template make the block off plate with some .25 aluminum. (Or buy one from Skirmants (810)575-9540 they have lots of nice stuff for 356 and 912 motors) Install a Facet solid-state fuel pump (1 to 4 psi unit Part # 1103 $44 from Pegasus 800 688 6946) on the left side near the fuel tube that comes from the front. Run fuel tubing from the tank tube to a filter then to the pump. Please don’t use a trak auto clear glass type of filter they will leak and don’t filter worth a damm. I recommend that you also install a fuel regulator so you can set the pressure to what the carbs require. I don’t know which carbs you have but for example, Webbers need 3 psi and for that app you would use (P# 1135-1to4. $30). From the pump or the recommended regulator you run fuel line to the existing carb lines. Use fuel hose clamps on all lines.
To hook up the electric you will need to ground the black wire. I use one of the fuel pump mounting bolts. The red power wire should go the rear fuse box fuse that is hot when the coil is hot. Turn the key on and off to determine the correct fuse. Be sure that the pump is off when the motor is keyed off or it will flood the carbs and run the battery down. I recommend that you add a fuel kill switch. (P# 1108 $65). It will kill the pump in an accident.

As you can see the easiest and cheapest thing to do is rebuild the mech pump.

Excess gasses (blowby) from the breather is normally a sign of worn rings or other bad things. Are you getting so much gas that the case is filling up with fuel/ oil mixture? If not I recomend that you do a leakdown test to see if the heads and pistons/cylinders are in good order.

The bursh inch and 5/8 header set with a stinger, requires, for optimum performance, a different cam (280 or higher) and to be cut to length more so that the timing to be adjusted. I use a bolt on glass pack for the street and a tuned “J” pipe for the track and both call for the same timing (5 to 6 deg BTDC using a 050) as tested by dyno time. The tuned “J” pipe gives about 10 HP over the glass pack at 6800 RPM. The stinger or “J” pipe will not add that much under 4000 RPM so it is more noise than power on the street. I have to adnit that it does sound GOOD when the motor goes up on the cam. BeerrrrrwwwwwwaaaaaaaaAAAAAAAAAAAAAA!

[Alex 67]

The oil just smelled like gas so I guess something was sticking. I had the original solex's rebuilt so that also could have caused the problems also. I will do a leakdown test this weekend to see about any other problems. I do have some crud rust showing in my fuel filter so that also might be causing some problems. I have a used tank on its way. I am painting the original exhaust and will have it on tomorrow and adjust the timing to see if that will resolve the problem. Thanks!!!!