I search all the forums and cannot find the O-ring size!!
It's 65mm x 2.5mm and it's easily fixed in-situ.
You'll need 4x 50mm x 6mm allen-key bolts and cut two down to 45mm.
Never let the pump casting come out further than when the O-ring grouve is fully exposed.See pixture.
Replace the shallow depth spline head bolts with the 45mm from above. Then all bolts
are the same 5mm allen-key.
Proceedure:Remove all the stuff in the way, throttle cable, auto Tx cable, fuel
back to tank piping 17mm plug into the pump, the four (or six) injector pipes, leave the lift pump there if you
can get to the shallow spline key bolt nearest the engine block and loosen it and replace
it with the 45mm bolt obtained above. Screw it in all the way but not tight. Replace the
other shallow head one opposite. Remove the throttle cable bracket and the auto Tx cable bracket
(if you have one).
Now, this is the tricky bit. Some forums mention, remove the bolt in the centre
between all the injector outlets and insert a "feeler" small drill and crank the engine to where it comes
furthest. I did not do this and all was well.
Loosen both remaining bolts slowly on either side of the pump steel casting and the internal spring will push the casting out to where you can see the O-ring. Break the O-ring and remove the pieces. Measure it, 2mm x 3mm oval section because it's had it.
Streach your new O-ring over the pump body and into the grouve. Put in two bolts, opposite (top and bottom) to hold the casting from coming out further and remove the rear bolt to let the O-ring fall into the grouve. Now streatch the O-ring over the fuel cut-off solenoid, remove the last bolt to let the O-ring fall into the grouve. Make sure the O-ring is in the grouve all around. My 65mm x 3mm O-ring had streached a bit and I had to push it into the grouve as I tightened the bolts. This is where a more stretchy O-ring may be easier.
Tighten the bolts pulling the casting back into the body. Note, the 50mm bolts will bottom out when not holding a thick bracket on, this is why 45mm bolts are used. Now, actuate the lift pump by hand until you see fuel coming out of the return-to-tank port. Replace all the throttle and auto cables brackets, then the return-to tank piping plug, then the injector tubes, leave the tubes loose at the injectors. Crank the engine until you see fuel come out at the injectors. Tighten the tubes there and start the engine. DONE.
Here is a pixture, note the fuel-cut-off solenoid is removed. I did not remove it. This looks so easy to get too.