The pump has about about 10 heat cycles and around 100 miles - all running great.
While there are several injection pump swap instructions out there, I'll focus on the things that I've learned that make the process it go more smoothly. There is plenty of chance for error, so I'll repeat what we all know helps any project - go slow, be methodical, and take notes.
Disassembly:
- Disconnect power
- Remove intake - it's been a while since I had the intake off, so I made a quick diagram of where the hardware and grounds went
- Plug or fill all 8 intake ports and the 2 exhaust crossover ports. I used duct tape.
- Remove throttle and high idle hardware and the kickdown cable if you have it
- Remove oil fill and carefully remove the 3 screws connecting the timing gear to the pump, rotating the engine to access each screw. I rotate at the flywheel; some people rotate at the crank. I do not recommend bumping the starter.
- Disconnect injectors at the pump (16mm modified box end, and matching crows foot for the bottom 2 lines (or 5/8", which fits tightly)
- Loosen lines at injectors 1, 2, 3, 4, and 6 and 7 if they're easy to reach; now the lines will move a little and allow the pump to come out more easily
- Remove the 3 nuts holding the injector pump, and carefully remove the pump. The pump fits tightly in the timing gear, and take care to not disturb that now loose timing gear too much that it jumps a tooth from the cam gear - very difficult to do, but if that happens, you'll have to pull the accessories, water pump and plate, and reindex the timing gear. Just take your time.
- With the pump on the bench, remove the TPS, rear supply fitting, and
Get your pump rebuilt by an authorized Stanadyne dealer, and take the opportunity to get the 12 point 15mm nuts for the pump to timing gear. Get a good set of torque wrenches - 3/8" and 1/2" - or make sure yours are still calibrated correctly. I like the Craftsman Digi-Click.
Reassembly:
- While the pump is away, I use a 3M scotch brite blue disc to clean the gasket surfaces - heads, intake, upper plenum. The front cover cleans up quickly with 600 grit.
- Vacuum each intake port, the valley, and surrounding area - just in case there's some grit or junk that found it's way in there.
- All gaskets go back dry - leave the copper, permatex, and RTV on the shelf. I've tried them all, and they don't help on the intake side. I've only ever used FelPro.
- I put my TPS back on at the bench before installing the pump - whatever works for you
- Rotate the pump to align the dowel pin with the timing gear
- Carefully install the pump onto the timing gear and front cover - take your time
- Torque the injector pump to timing gear screws to 20 ft-lbs
- Align the timing marks on the pump and front cover - should be 0* BTDC, a level suitable for both NA and the vast majority of turbo setups. Err toward ATDC (tilt the pump one line-width to the passenger side) if you make a lot of boost (>15psi) and/or run greater than 70cc of fuel. One line-width is about 1.5*-2*.
- Torque the injector pump body to front cover nuts to 30 ft-lbs - you can't get a torque wrench on these, so I just make sure they are reasonably tight
- Reassemble injector lines to the pump - start with the bottom two and work your way up and around.
- Retighten lines at the injector, except 1 and 3 (those are the two you'll bleed for startup and are the easiest to access)
- Reassemble throttle and high idle and the kickdown
- Pull the plugs or shop rags from the intake ports and reassemble your intake following the factory torque pattern - I go in two stages and do a retorque after the first heat cycle
I recommend doing the first fire without the intake - makes it easy to check and resolve leaks at the pump. Just get your grounding hooked up, and you can operate the engine without the intake. I leave the serpentine belt off, too, since I'm usually laying across the radiator checking for leaks with a flashlight.
Regarding bleeding and getting the first fire, I have an electric pump, and bleed first to the filter. Then, with a helper cranking in short 5 second cycles, I bleed lines 1 and 3. Next, it's usually only one or two 8 second cranking cycles should get the engine started and it will chug out the rest of the air. If you're doing this with the intake off, you can see the exhaust crossover ports start to puff and confirm you're headed in the right direction.
Here's the one 8 second crank and first fire:
All done and back together.
I'm sure I've left out a few things, but I hope this helps.
David
