Introduction: Replace a Mechanical Fuel Injection System on 1981 VW Rabbit Diesel - Bosch VE
This dives right into replacing a mechanical fuel injection system on a 1981 VW diesel Rabbit with a 1.6L engine. Bosch VE pump.
Installing pump, injectors, and fuel lines.
You should still use a service manual, this one is very good but hard to find:
Volkswagen Rabbit/Scirocco/Jetta Service Manual, 1980-1984: Including Pickup Truck, Convertible, and GTI (Robert Bentley Complete Service Manuals)
This one is less good, but you can get it easy from amazon:
VW Rabbit Diesel 1977 thru 1984 (Haynes Manuals)
Everything is in chronological order -- it starts with the fuel system already out.
A word about the motivation for this instruct able:
"assembly is the reverse of removal"
There are very good reference books for working on cars; Haynes, Chilton,
Bently. However they have a few drawbacks; the first is that
most of the photos are black and white and grainy. It is not their
fault, it is hard to take pictures inside the engine compartment or
under the transaxle. The second major drawback is the statement
"assembly is the reverse of removal". Most manuals are based an a
complete teardown of the vehicle. This is very useful if you want to
take a car apart peice by peice. However, once you take the car apart
and have peices all over the garage, spilling out into the drive way
and family room. You are generaly left with these instructions
"assembly is the reverse of removal." Even if you follow the
instructions backwards, line-by-line it is very difficult to get
everything back together. In my opinon these books should start with
a pile of parts and end with a completed vehicle.
So I have started this instructable with parts all over the place and
every bit of timing out of sync. Hopefully, when you hit the words
"assembly is the reverse of removal", you will find this instructable
and it will help yout out.
Why repair a car from 1981?
55 miles per gallon, no modern emissions rules, cheap parts, and cheap
Why diesel? Well, check out the work being done by Rudy Behrens of
He is building living robotic systems that grow oil rich algea and
process it directly into usable diesel fuel.
Here is a nice article on the project: here
What else do you need to know?
Where to get parts:
http://www.partsplaceinc.com/ -- These are VW specialist, every part has been perfect. Very good if you want to buy 'kits', such as all new hoses or a complete engine rebuild kit. They also carry many specialty tools and such. They are a 'real' store, so you can get them on the phone an they will be able to help, keep in mind that they are also minding the shop, so they might be busy with physical people.
http://www.partsgeek.com/ -- Often have the best prices (not always though) good for pretty much anything for any car, but the descriptions are very brief so you need to be careful when ordering. Fast shipping.
AutoZone is okay, but prices are sometimes high and some parts ship slow, if one part is back-ordered or custom they delay the whole order. Of course there is probably one near by, so you can go there in person, cheap fluids - expensive tools. I like smaller stores better.
Local salvage yard -- In New England you will be about salvage cars tend to be around 10 years old.
Ebay -- I have not had good luck.
Amazon -- Look for deeply discounted professional tools. I used this and it worked:
VW/Audi Bosch Diesel Fuel Injection Pump Timing Indicator Tool
Harbor Freight -- most of my car tools are from here, go to the store if you can. I like the color coded wrenches/sockets.
Home Depot -- not too useful.
Craigslist -- Look for someone who is getting rid of a garage full of VW parts, or a parts car.
Also -- The car I am working on is the former ' Clean Machine ' from Gordon Collage in Mass.
Also - I like this wrench set from Harbor Freight because I can remember the colors.... link
Step 1: Why Buy a Rebuilt Pump?
You will need a working pump, I recommend buying a rebuilt pump. Rebuilding these pumps is hard. Even if you get it back together, there are several important calibrations that can't be done at home. The injection pump controls everything the engine and prevents run-away acceleration.
Here are some pictures of a pump rebuild -- I never got this one working correctly.
Step 2: Diesel Fuel Injectors
Diesel engines have fuel injectors instead of spark plugs. It is a precision part so buy new ones if you can - but they run $50 to $150 each.
Step 3: Heat Sheild
Also get new heat shields. They say to replace these every time the injectors are removed.
Step 4: Buy a Rebuilt Fuel Injection Pump
The fuel injection pump is complicated and has to be carefully calibrated.
Re-manfuctured they are about $500 -- got mine from Parts Place VW
Step 5: Here Are Some Other Parts That Go on the Pump
These parts are important, but do not come with the pump. I pulled them off the old one.
Step 6: Install Fuel Injectors
Install the fuel injectors. Make sure the old heat shields are out. Put in the new heat shields. Put a little high temp anti seize lube on the threads. The injectors have to be tightened correctly; so you need a torque wrench. The socket is 27mm.
Here is a link to the anti-seize lube on amazon:
Permatex 81343 Anti-Seize Lubricant, 1 oz. Tube
Step 7: Pump Brackets
The pump mounts with 4 bolts.
3 on the face and one at the other end.
One bolt is on a bracket and has to be tightened through a hole in the sprocket.
Step 8: Put This Hose in Place
Now is a good time to put this hose in place.
Step 9: Start Setting the Timing -- Lock the Pump Sprocket
Line up the timing marks on the sprocket and pump. Then lock the position using this special pin. It goes through a whole in the sprocket and into a hole on the bracket.
Here is a link to this kit on amazon -
VW/Audi Bosch Diesel Fuel Injection Pump Timing Indicator Tool
Step 10: Paint the Cover for the Cylinder Head
Paint the cylinder head cover with engine paint. Clean and sand it first.
Step 11: Get Flywheel in Right Position (engine to Top Dead Center)
Top dead center -- or TDC -- is sort of the starting point for the engine. When setting the timing everything gets lined up at TDC.
Line up the timing notch on the flywheel.
Step 12: Set Cylinder Head to TDC
With the cover off the cylinder head - rotate the camshaft to TDC. Both lobes over the first valve are pointed up and a flat timing tool fits in a slot at the other end.
Step 13: Here Are Timing Marks When It Is a Little Bit Wrong
Setting the timing may take a few tries, this is what it looks like when you are close, but are not given a cigar.
The pump is lined up but the flywheel is off by about 1cm.
Step 14: Set TDC Again and Install Belt
It is hard to keep everything lined up.
I had to loosen the sprocket on the camshaft. To do that, you have to lock the camshaft in place (withouth scratching it), loosen the bolt, then 'tap' the sprocket with a mallet to get it loose.
Now, Set the timing again, jam on the timing belt, then tighten the sprocket again.
Also -- I put graphite on the pump sprocket, this made it much easier to get the belt on.
Step 15: Install the Cold Start Cable
Set the knob so it is pulled out just a little. Push the cold start lever all the way to the passenger side. Attach the cable.
Step 16: Cold Start Cable Knob Pulled Out
When starting the engine you pull out this knob.
Step 17: Replace Accellerator Cable
The accelerator cable should be totally replaced, for now I put the old one back on.
The cable hooks on a bracket that is transferred from the old pump.
Step 18: New Fuel Line
Install a fuel line from the filter to the pump, use a clear one.
Step 19: New Gasket for Cover
Install a new gasket for the cover. It has 3 parts.
Step 20: Put the Cover Back On
Put the cove back on. I sprayed the edges that will touch the gasket with graphite, there was some bare metal and I didn't want to paint it.
Step 21: Fine Tune the Timing
The timing has to be fine tuned using a dial gauge. If you have experience you might be able to do this 'by ear' with the motor running. The gauge is from a kit.
Here is a video that shows the way the pump can be rotated. It is pretty loose here.
Step 22: Remove This Thing That Is in the Way...
Had to remove this thing to fit the dial gauge in place. It goes into the side of the pump.
Step 23: Take a Bolt Out of the Pump
There is a bolt in the side of the timing pump. It is in the center on the drivers side. This is where the gauge will go. Take out the bolt, do not loose the washer.
Step 24: Dial in Place
Screw the dial gauge into the hole where the bolt came out of.
Step 25: PUSH IN THE COLD START KNOB
when you do the fine tuning with the dial gauge, the cold start knob has to be pushed in
Step 26: Find the Low Point
With the dial gauge in place rotate the engine backwards a little bit. You are looking for a point where the needle stops moving.
Then set the dial gauge to zero. Then rotate the engine the normal way to TDC. Then you rotate the entire pump until the dial gauge shows the correct value, check a book, it is about 1mm.
This sets the amount of fuel that is injected.
Here is a poor quality video -
Step 27: At TDC - Calibrate
Set to TDC and read the dial gauge. This is the value we are trying to get correct. Look up the calibration value in a book.
Then - loosen the bolts on the injection pump bracket and rotate the entire pump such that the dial is at the calibration value.
Step 28: Tighten the Bolts
With everything perfect, tighten up the bolts holding the pump in place. The pictures here show me setting the wrong torque and breaking a bolt. So.... you should do it right and not break anything.
Video of trying to tighten to the wrong torque. Set to 25 ft/lb instead of 25Nm.
Step 29: Put the Back the Bolt and the Other Pump
If that worked out, remove the dial gauge and replace the bolt with the washer. Also, put back the thing we had to take off.
Step 30: Install High Pressure Fuel Lines
The fuel lines that go from the pump to the injectors are metal and curvy. I bought new ones, but they can probably be cleaned.
Step 31: Install the Metal Fuel Lines --- Be Gentle
Each fuel line is different. Fit everything in place loosely. Don't break anything. Don't cross thread anything. Use a light touch. Get everything 'finger tip' tight.
Step 32: Tighten Up -- Genlty
Now tighten all the joints. Tighten just enough -- you don't want to break these. It will be easy to tighten them latter if there is a leak.
Step 33: Put Little Fuel Lines Between the Injectors
There are barbed ports on the injectors. This is for fuel return as not all the fuel gets injected. Replace these with new hoses.
The injector all the way to the drivers side is a dead-end. So you need a plug or to clamp a piece of hose.
Step 34: Wire to Fuel Solenoid
There is a solenoid on the pump that controls the flow of fuel.
If you have to fix the wire, here is how.
Step 35: Fuel Return Line
Not all the fuel gets injected so it has to go back to the tank. There is also a low pressure resevoir in the pump which always has fuel going in and out. There is a tiny hole that must be clear.
Step 36: Power
Everything is now installed... probably.
To test things out we will need some power. It is hard to start the first time. I hooked up a giant power supply used to fast charge batteries.
It is good to have a fire extinguisher. Find a fresh one....
Step 37: Get the Air Out -- Bleed
The pump and all the fuel lines need to be filled up with fuel.
This already has an extra electric pump. I ran that for a while to get the air out and fuel in. You can also do this by removing the "out' bolt and pouring fuel in with a funnel -- then slightly unscrew the metal fuel lines at the injector and run the starter motor to get air out.
Step 38: Crank the Engine -- Does It Work?
To start the engine; pull out the cold start knob. Turn the key part way to turn on the glow plugs. Put the car in neutral and set the hand brake.
Here is a video of the engine running.
Notice that no exhaust comes out the tail pipe, so there is a big hole somewhere...
Step 39: Video of Engine Not Running
Here are some videos where nothing works and nothing happens.
More of the same.
We have a be nice policy.
Please be positive and constructive.