how to injector seals

8/13/2019 How to Injector Seals

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Replacing fuel injector seals.

Symptoms.Poor starting – requiring lots of cranking. Almost impossible to start when left facing

uphill. After a while it becomes difficult on the flat or with a low level in the fuel tank.The reason is that the fuel injector leak off pipes or seals are leaking air in and the fuel is

draining back into the tank. It then requires lots of cranking for the fuel pump to pull thefuel back through. In the worst cases it cannot. To test if this is the case take off the top ofthe fuel filter and see if it is brimming with fuel. If not you have ‘leakback’.

There are three areas where the air can get in. The injector rubber leak off pipes which

are a push fit and are under the engine cover/wiring harness. Easy to change. The earlyoriginals were cloth covered and will definitely need replacing.

Try those first.

Second and fairly unusual is a leaking fuel filter housing. Replace the filter and the twoseals. Clean off the housing with brake fluid cleaner and look for staining – perhaps from

a crack in the top casting?

Next are the fuel injector cross over seals within the cylinder head. There is a rubber and

metal seal under a cast iron flat ‘pipe’ that goes into the cylinder head. The leak off bit is

a small hole. Hard to believe but these do leak badly and when they go they get worse

over just a couple of days.

ToolsTorx socket set. 17 mm spanner (preferably 17 mm pipe union spanner) , 27 mm spanner.18mm socket. 10mm socket, torque wrench.

Parts

Also, here's the other items for future reference:Injector seal Injector to cyl head seal SEAL, RING, INJECTOR NOZZLE HOLDER

TO CYLINDER HEAD 9117693

Inlet manifold gasket x2. (£3.69 each) 90500940 + 90572108

Camcover gasket (optional it can be OK to reuse)

Crossover ‘O’ rings x4 (44p each) 'O' RING, INJECTOR NOZZLE

HOLDER TO CYLINDER HEAD 90500732

Injector to crossover seals x4 (£5.20 each) SEAL, RING, INJECTOR NOZZLE

TO INJECTOR NOZZLE HOLDER 90502704

Injector to cylinder head copper washers/seals x 4 if required

SEAL, RING, INJECTOR NOZZLE HOLDER TO

CYLINDER HEAD 9117693

Leak off hose ( £14.35! comes as one length) HOSE 93181131

Optionally 3 leak off ‘T’ pieces – (£3.06 each can be brittle and snap).DISTRIBUTOR 9281478



Cam shaft pulley bolt. (should be renewed each time as it a stretch bolt – I

don’t though)

Torque settingsCanshaft main bolt - 66 lbs/ft, then 60 degrees then 30 degrees

How to:-Remove insulation cover

Unbolt the wiring harness (2 bolts pictured) – disconnect the two wiring plugs by the

front end and the one on the inlet manifold and lift the harness away and lay by the battery.



Remove the EGR valve by taking off the two bolts. Push the vacuum pipe off with ascrewdriver -don’t pull it.



Marvel at how dirty it is!

Clean the injector and leak off pipe area (with brake cleaner?)



Pull off the leakoff pipes x 4 and the long connection down to the pump.

This pic only shows the end of them

Remove the fuel pump wiring socket by pulling out the red locking plate and then pullingthe plug out.

Remove the injector pipes, 17 mm spanner. The one at the bottom rear is a bit of a pig. I

needed a 17mm off set brake pipe union spanner.

Cover the exposed ends of the injector pipes. The fuel pump ends can be covered by a

large rag. The cylinder head ends I covered with tape and pushed on aerial plug ends tohold the tape in place.



Remove the inlet manifold top cover. Remove the pressure sensor before cleaning.Groan at the amount of muck within.

Remove the inlet manifold – the 10mm nuts are there under the crap.

Clean the inlet manifold and top cover.

Remove the actuator solenoid to assist in cleaning and prevent it getting contaminatedwith solvent etc.

The deposits are not baked on and scrape off quite well. Use a plastic scraper such as a

kitchen washing up brush with the chisel edge on one end. Then use Gunk or jizer withstiff brush to clean it all up finally – rinse off.

Beware this a filthy job – do not do it in the kitchen. If you know a engine shop with a

caustic hot washer - pay to have it done!



A clean one

Clean the inlet ports in the head. I have read of a spoon with the edges bent in a a scraper – but I use a piece of 22mm copper pipe clamped by hand onto a vacuum cleaner hose.

The ports are fairly horizontal so the crap does not fall into the valves easily. The vacuumeffectively prevents the crap going too far. I then finish off with a 15mm piece of copper.

This gets rid of 90% The final 10% is almost impossible to remove without it going downinto open valves.



Remove the vacuum pump. There are 4 bolts. You need to undo the wiring support and

bend away to reach one of the bolts. (as below)

Remove the cam cover bolts. Ease the fuel pipes up and away from the front of the cam

cover. Release the breather hose. Remove the rear wiring harness bolt on the top of thecam cover. Push the wiring harness ½ inch back towards the bulkhead to release it from

the tongues that stick out of the cam cover. Lift away the cover.

According to the book you now need £100 of special tools to lock and set the timing.This site says you can get away without and I now agree.Set the engine to TDC. This is when the first two cam lobes are at 10 and 2 O’clock.

A further guide is that the

vacuum pump slot in the end of the cam should be horizontal AND the timing mark/holeat the top. If this is not right rotate the engine a complete 360 degrees and the vac pump

hole will then be at the top and the cam lobes facing up at 10 and 2 O’clock.



Adjust the engine position by placing in reverse and pushing backwards to rotate theengine or in first and push forwards. You must not rotate the engine backwards ( i.e. in

first and push backwards, reverse and push forwards).

IMPORTANT – scribe marks on the cam pulley and the cam itself. Don’t use paint – it

will come off with the oil. A sharp screwdriver will do. The marks must be good enough

to ensure that you replace them in exactly the same position.

Place a cable tie around the chain and into a cam pulley hole and tighten to keep the chain

in place. I used a bungee cord very tight into one of the bonnet holes and hooked in to the pulley to put a considerable pull on the pulley towards the windscreen. (ignore the drill

bit in the pic – not necessary)



Place a 27 mm spanner on the camshaft casting where it is cast to a hex shape to hold it in

place.

Undo the cam bolt with a 18mm socket. Gently lever the pulley off. There is no keywayand it comes off easily (the timing is set by the position of the pulley on the cam – hence

it is infinitely variable and the two are just clamped together with a high torque).

Remove the camshaft caps. Remove by undoing the bolts ½ turn at a time in a spiral

pattern until they are all free. Do not be tempted to remove them all in one go – the cam

cam snap or bend the cap bolts. They are machined in place and MUST be refitted in

exactly the same place as they come out. Clean and mark them or place somewhere safe

in exactly the right order and orientation.

Lift out the cam shaft and place it in clean rag and wrap it up.

Remove the injector crossovers by removing the bolt and them lifting slightly andlevering back towards the front of the car. There is an ‘O’ ring that can be a bit tight.

Sometimes the injector stays in place and sometimes it lifts out, whichever carefully lever

off the top injector seal. Also remove the ‘O’ ring and replace.



Clean the ‘O’ ring recess. I find that a smear of silicone grease helps the crossover to be

pushed back in.Tighten the crossover bolt by hand as far as you can – then turn 360 degrees – note this is

not really tight but seems to crush the seal just enough. If you overtighten the leverage on

the top of the injector is too much.

All that remains is to re-assemble in reverse order.

When replacing the cam cover put a smear of silicone sealant in the corners around the

rear camshaft cap. (the two lower arrows). Clean up the surface (brake cleaner again) andthe corresponding gasket (if reusing the old one)

Tighten the cam caps in the same spiral pattern a bit at a time to keep even pressure on

the camshaft.



ENSURE that the cam marks match exactly when refitting. Only when fully tight release

the tie wrap and bungee cord.

The fuel system will be empty and it is notorious difficult to bleed the fuel through. It

takes many minutes of cranking to get the fuel through- often enough to flatten the battery.

To help, fill the fuel filter to the top with diesel and refit the cover quickly.Leave the inlet manifold hose off. Get an assistant to turn the engine over on the key -whilst cranking squirt Bradex ‘easy start’ into the inlet. It will run on this alone and the

key can be released – vary the speed of the engine by the amount you spray in. After 20

seconds or so stop spraying and the engine may run by itself. If not repeat once more.

Some have sprayed brake cleaner as this also works but not quite as well as ‘easy start’.

Conclusion:The engine now starts when parked on a hill facing up! Best is the improved performance

from cleaning the inlet manifold and ports. The power is increased lower down, so the

power is now progressive without the dead area below 2000rpm. Makes the car much

more driveable.Top end power is also improved. MPG seems 4-5 better as you don’t spend so much time

at full throttle.

how to injector seals

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