kmead
Old enough to know better
A few years ago I had one of my OE cloth covered fuel lines from the pump to the filter burst, no surprise as it was well past its use by date. I had bought some 7.5mm fuel hose prior to this as it was my intent to replace them anyway so I was prepared for this eventuality.
Happily this is a very easy job requiring just the loosening of clamps, a few nuts and then cutting the new hose to length.
Unfortunately I was among those caught in the defective hose that was somewhat prevalent at the time, so this year, less than three years on when I unpacked the X I found the hoses now look like this:
Note the checking and cracks that run annularly and lengthwise on the hoses.
In contrast the main feed hose to the injector header and the injector hoses from Pirelli in 1984 when the car was built looks like this:
I am not suggesting it is good practice to run a hose this long but the difference in material quality is striking. I will be replacing them later this month along with the injectors, hoses and related hardware.
Enough about me and my questionable life practices, on to the main activity.
Materials needed:
(MWB offers a hose kit which replaces everything from end to end, others carry the piece parts)
Tools you will need:
What will you be doing?
Replacing the primary hoses from the fuel pump to the fuel filter, the fuel filter to the hard line leading to the injector header and then the low pressure return line to the tank are all in easy reach. There are two other lines under the car which I will be replacing as soon as I drive the tank to near empty (right now it is full) and I will update this post to cover those in a week or two.
Happily this is a very easy job requiring just the loosening of clamps, a few nuts and then cutting the new hose to length.
Unfortunately I was among those caught in the defective hose that was somewhat prevalent at the time, so this year, less than three years on when I unpacked the X I found the hoses now look like this:
Note the checking and cracks that run annularly and lengthwise on the hoses.
In contrast the main feed hose to the injector header and the injector hoses from Pirelli in 1984 when the car was built looks like this:
I am not suggesting it is good practice to run a hose this long but the difference in material quality is striking. I will be replacing them later this month along with the injectors, hoses and related hardware.
Enough about me and my questionable life practices, on to the main activity.
Materials needed:
- 1 m/3ft of 7.5mm or 7.9mm ID high pressure fuel injection hose
- 1 foot of 12mm ID low pressure fuel hose, EU braided preferred.
- 8 injection type clamps for 13 to 15mm OD hose
- 4 17/19mm injection type clamps for 10mm ID hose
- A injection fuel filter, Mann 830 or 830/7 or a Bosch 0 450 905 030
- A 12mm 1/2” inlet/outlet low pressure filter WIX 33299 or similar
- NAPA 3299 replacement fuel filters
- CARQUEST 86299
- DONALDSON P551771
- FLEETGUARD FF5621
- Fram G11278
- LUBER-FINER G8219
Tools you will need:
- 10mm deep socket
- Philips screwdriver
- possibly a 7mm socket
- vacuum pump (handheld)
- a clean soup can
- a metal bucket 2 gallon
Replacing the primary hoses from the fuel pump to the fuel filter, the fuel filter to the hard line leading to the injector header and then the low pressure return line to the tank are all in easy reach. There are two other lines under the car which I will be replacing as soon as I drive the tank to near empty (right now it is full) and I will update this post to cover those in a week or two.
- First loosen the clamps for the rubber elbow going from the air filter housing to the Air Fuel Meter (AFM). Remove the nut or wing nut holding the air filter cover down to the housing. You can remove the cover and the elbow together or separate them.
- Next remove the the two 10mm nuts holding the air filter canister. To get the canister out without having to disturb anything else, pull the long tab which goes over the long stud on the firewall side back over the stud, then move the entire unit to the right to come off of the sidewall stud and then rotate the housing first downward than the cant it to come up between the AFM, the coolant reservoir and the fuel filter.
- The following is optional but it is good practice. Using a vacuum pump, pull the vacuum line off the manifold that leads to the fuel pressure regulator. Apply vacuum (@20) to relieve the fuel pressure in the pressure lines. If you don’t do this you will have a small amount of extra fuel to deal with when you pull one of the hoses. The fuel is under 37-43lbs of pressure so you can get a bit of spray in the next step if you don’t do this.
- Remove the two nuts with washers that clamp the fuel filter to the mount, the one is obvious the other is tucked around the back side. Remove the metal clamp half and the rubber gasket. The filter will now be held only by the hoses.
- Loosen the clamps on all the hoses and slide them towards the middle of each hose length. These are the low pressure return line on the right side of the engine compartment, then on the left side of the engine compartment the pressurized supply line from the fuel filter to the injector feed hard line and then the fuel pump to the fuel filter. A total of 6 clamps.
- Take a clean soup can and as you remove each hose starting from the low pressure line, pull off one end and let the resulting fuel spill into the can. You may have to twist the hose a bit to get it off if it hasn’t been disturbed in a long time. When you pull the hose off the rubber line leading to the hard line of the injectors you may get a spray of fuel so hold your hand over connection or a cloth so the fuel doesn’t spray onto you.
- Tilt the fuel filter over while holding the hose end into the can to gather as much of the fuel as you can. I put the can on top of the clutch slave area while doing this. Remove the fuel filter from the line from the fuel pump, keeping the filter inverted as you do so. Remove the filter with the hose and the can to continue to drain as much fuel from the filter as you can. The fuel should be clear and perfectly clean.
- Pour the fuel in the can back into the tank if it was clean. Next put the other end of the fuel filter into the can and hold it upright, more fuel should come out along with a bunch of sediment or other less than desireable muck. This is why you have a Bosch/Mann brand filter on your fuel system.
- Remove the hose from the fuel pump while holding the end of the hose in the can to catch the fuel in the hose.
- Lay the hoses out to match their length and cut using either a hose cutting plier available at Home Depot or other big box store or a sharp utility knife.
- Put two hose clamps on each hose, placing them at about the center of the length so you don’t forget to put them on before connecting the hose.
- Install the hoses from the pump to the filter, filter to injector hard line and the low pressure return line. Tighten the 6 clamps.
- If the car is low on fuel you can move to the next step. Low on fuel means the low fuel light is on or flashing at you periodically. You will be draining the tank of all fuel in the next few steps. If you have a large container to hold 10 gallons of fuel have at it. Me? I like having the least amount of gasoline in a large open pan/bucket as I can.
- Lift the car and put jack stands under it as appropriate to keep the car off your chest as the next few steps will have you underneath the car.
- Remove the under tank splash shield, this is held on with screws.
- Grab your 1-2 gallon container, I suggest a clean galvanized bucket as it will ground easily, is stable and has a large opening.
- Tank to fuel pump hose is the large diameter hose leading from the tank to the fuel hose, it is likely a cloth covered hose. Loosen both clamps. Wiggle the hose to ensure it will move, it may ooze a bit of fuel at the ends.
- With the bucket under the fuel pump, grab the hose at the fuel pump end, pull down quickly and get your thumb over the end. Fuel will come out of the pump and the hose end if you aren’t quick. Turn the hose on the axis of the fuel outlet so the hose end is not pointing down into the bucket and let the fuel run freely. The faster it can run the more crap will get out of the bottom of the tank.
- If you have some extra room in the bucket you might consider putting another half gallon into the tank from the filler to try to get anything else out of the tank.
- Cut two pieces of hose and attach them to the large diameter fuel filter with two clamps. Leave the hoses long so you can figure out how to get this package in the space available.
- Attach the assembly to the tank and the fuel pump with two more clamps. You may have to finagle the routing of the hoses or adjust the length of the hoses to get appropriate radii as the OE solution didn’t have this extra filter.
- Return line to tank hose is the same diameter as the pressure line hose and uses the same clamps. As the fuel tank is now empty there shouldn’t be any fuel to spill. Cut an appropriate sized piece of line and reinstall with new clamps.
- Now go back through and tighten all the clamps again as they have a bit of time to seat.
- Refill the fuel save for the last cup or two as there is usually some schmutz you don’t want to reintroduce to the fuel system.
- With clamps properly tightened, it is time to pressurize the system to check for leaks. Turn the key to ON, not Start. Reach your finger into the AFM throat and move the flap back. The fuel pump will start and you can observe the various fuel lines. Release the flap. Do this a few times and then carefully inspect each of the connections.
- Assuming all is well, reinstall the clamp for the fuel filter, the splash shield under the fuel pump and finally the air cleaner and elbow.
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At my last inspection they were in good shape but that doesn’t mean they actually are in good shape.