DIY - Fuel Removal Process
07-08-2014, 09:25 PM
#1
Three Wheelin'
Thread Starter
DIY - Fuel Removal Process
I recently needed to empty my fuel tank and investigated and tried several methods. The method shown below is painless, completely empties the tank, and offers the opportunity to measure the fuel flow rate "while you are in there." The Porsche workshop manual shows how to measure the fuel flow rate, and this method is used to access the fuel and pump it out of the car using the car's fuel pump.
In more detail, the procedure went like this:
1. Pop the engine lid and install your favourite protective blanket over the left rear paintwork.
2. Remove the heater fan assembly by disconnecting its two electrical connections at the back and one on the left side, two vacuum connections at the back, the two rubber collars that attach to it, and removing two 10mm bolts on the left hand side of the assembly. At this point, you've got this:
3. Locate the fuel return connector behind where the heater fan was:
I placed a rag underneath the connector to catch any fuel, but very little leaked out once the connector was open.
4. Use 22mm and 19mm wrenches to loosen the fuel connector and turn off remaining threads by hand. The 19mm nut was not torqued very tightly and unthreaded easily, so this was very quick.
5. The male connector is an M16x1.5mm thread, in case you want to make a tool like the Porsche Special Tool 9507. Here, I measured the OD and used a tap as a thread gauge to get these specs.
6. I intended to make a 9507, but not having that connector on hand, I simply finessed a section of 1/2" vinyl hose over the male connector and secured it with a hose clamp. I also loosely tie wrapped the hose inside the engine bay at a point to ensure the hose did not kink, ie ensured a smooth bend radius as it exited the engine bay, as not illustrated in this photo.
7. Using the jumper as described in the workshop manual I operated the fuel pump, and here we see the fuel being pumped out.
Exercise caution to ensure that no fuel is leaking into the engine bay, and please, no smoking, it could be bad for your health.
The manual states the minimum flow rate to be 850ml per 30sec. I found my flow rate to be approximately 1125ml per 30sec. This could explain why the Polar Silver cars are fastest.
In more detail, the procedure went like this:
1. Pop the engine lid and install your favourite protective blanket over the left rear paintwork.
2. Remove the heater fan assembly by disconnecting its two electrical connections at the back and one on the left side, two vacuum connections at the back, the two rubber collars that attach to it, and removing two 10mm bolts on the left hand side of the assembly. At this point, you've got this:
3. Locate the fuel return connector behind where the heater fan was:
I placed a rag underneath the connector to catch any fuel, but very little leaked out once the connector was open.
4. Use 22mm and 19mm wrenches to loosen the fuel connector and turn off remaining threads by hand. The 19mm nut was not torqued very tightly and unthreaded easily, so this was very quick.
5. The male connector is an M16x1.5mm thread, in case you want to make a tool like the Porsche Special Tool 9507. Here, I measured the OD and used a tap as a thread gauge to get these specs.
6. I intended to make a 9507, but not having that connector on hand, I simply finessed a section of 1/2" vinyl hose over the male connector and secured it with a hose clamp. I also loosely tie wrapped the hose inside the engine bay at a point to ensure the hose did not kink, ie ensured a smooth bend radius as it exited the engine bay, as not illustrated in this photo.
7. Using the jumper as described in the workshop manual I operated the fuel pump, and here we see the fuel being pumped out.
Exercise caution to ensure that no fuel is leaking into the engine bay, and please, no smoking, it could be bad for your health.
The manual states the minimum flow rate to be 850ml per 30sec. I found my flow rate to be approximately 1125ml per 30sec. This could explain why the Polar Silver cars are fastest.
07-09-2014, 12:38 AM
#2
RL Technical Advisor
Paul,
Please remember that these pumps are cooled by the fuel that circulates inside them and running the car out of gas, also starves the pump of cooling & lubrication. This is the main cause of premature failures.
I'd strongly recommend draining the tank either by siphoning or using a transfer pump made specifically for this purpose.
Please remember that these pumps are cooled by the fuel that circulates inside them and running the car out of gas, also starves the pump of cooling & lubrication. This is the main cause of premature failures.
I'd strongly recommend draining the tank either by siphoning or using a transfer pump made specifically for this purpose.
07-09-2014, 02:00 AM
#3
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^^^^^++++1000. As i was starting to read it, I thought it's not a good idea to run your tank dry or even close. Maybe to check flow rate, that's it.
But you are correct, Polar Silver is the fastest :-)
But you are correct, Polar Silver is the fastest :-)
07-09-2014, 07:42 AM
#4
Three Wheelin'
Thread Starter
Yes, this is a good point I neglected to mention. I pulled the jumper to stop the fuel pump the instant the pump sounded like it was not getting the full amount of fuel.