volvopaul
Well-Known Member
At last, all injectors removed and compression test carried out.
Presumably the injectors on a well serviced engine are relatively easy to pull but these weren’t.
The cheapest puller I could find was £50 or so, so I kept with my home made version,:
Had to make sure the sleeves were not disturbed.
Also seems to be as important to turn the injectors as pull them, and using a spanner across the fuel return flange is not a good idea as this damages the flange.
Far better remove the adjacent hold down stud and bracket to get a spanner on the flat part of the injector..thanks Volvopaul...and removing the adjacent head bolt made it easier still!
One injector would not shift even though it was free enough to rotate it by hand. When it did eventually come out, it fell apart as it came clear of the head, the nozzle casing was split and I think it was the nozzle that was stuck whilst the body rotated.
The injector that I couldn’t get the puller on to due to being under the rear deck luckily came out by just rotating with a spanner.
Anyway they are all out and this is what they look like:
Whether an injector specialist can do anything remains to be seen.
Will let you know what they say.
So on to the compression test, and true to form, none of the fittings included in my ebay purchased set seemed made for this particular application but it was fairly easy to put together something that worked:
And the results?
Cylinders 2 to 6 all reached 250lbs per sq in
Cylinder 1.............................nothing.
Quoted required compression 355.
However my test was on a cold engine that hadn’t been run for a couple of months, I did wonder how a test on a warm engine could ever be done given the work up to get a test on once you have stopped the engine!
Internet wisdom seems to be that cold tests can show 30% less than spec figures which would make my good ones ok, but more significantly I think they were all near identical figures which is good.
So there I am...one bad number 1 cylinder.
Did a quick check of that cylinder’s valves under the rocker cover, nothing looks wrong and the clearances are normal.
Pretty sure it needs a new piston and liner.
So next step?
Well the head is coming off.......just got to make up my mind whether to do that before or after I take the engine out
As you have gone that far now I would take the head off before you take the lump out, you never know it could be the compression ring on the head gasket that's failed allowing compression into the crankcase, you may find no damage to piston and liner. Had the rings gone you would have something on the gauge maybe only 20/50 psi as it built up.
To see zero that means the whole lot is bypassing somehow.
Are the inlet and exhaust manifolds off? Look down the ports at the valves , you can now at this stage with rockers removed and valves shut pressurise the cylinder down through the injector aperture , you would then hear the blowby going into the crankcase , or if its a failed valve gas blowing into the manifolds.
