C

chris freestone

Active Member
hey guys hope your all good:)... i think i already diagnosed the problem with this one just need to know what i can do about it. got a 200tdi engine which i recently rebuilt and it was running perfectly until lately its been a down on power and cloud of black smoke when i start up. on inspection i noticed it was pushing fuel out from around the injector on the front cylinder and if you held your hand next to it you could feel air comeing out as the engine ran. so i took it out and it was covered in black sooty deposits and i mean covered, i think this may have happened because when i fitted the injector originaly i may have put the litle copper washer on upside down. anyway i cleaned all the soot off the injector and as best i could from around the hole, and refitted the injector with a new washer... the leaking air/fuel has now stopped, i havent driven it yet but i can tell it still is running quite rite. i took the little fuel pipe which runs between the injectors off and on this injector when you rev the engine fuel ****es out but nothing comes out of the others if i do the same. so im guessing that the fuel valve in the head is blocked with this sooty crap??? if so is there any way of clearing it without removing the head, could i just simply drive it out over time with the use of redex? also am i gona cause any more damage if i keep driving with the engine in this state? what do people think, open to any suggestions... im no expert just goin of what i know.

thanks in advance for your replys chris :):)
 
chris freestone said:
hey guys hope your all good:)... i think i already diagnosed the problem with this one just need to know what i can do about it. got a 200tdi engine which i recently rebuilt and it was running perfectly until lately its been a down on power and cloud of black smoke when i start up. on inspection i noticed it was pushing fuel out from around the injector on the front cylinder and if you held your hand next to it you could feel air comeing out as the engine ran. so i took it out and it was covered in black sooty deposits and i mean covered, i think this may have happened because when i fitted the injector originaly i may have put the litle copper washer on upside down. anyway i cleaned all the soot off the injector and as best i could from around the hole, and refitted the injector with a new washer... the leaking air/fuel has now stopped, i havent driven it yet but i can tell it still is running quite rite. i took the little fuel pipe which runs between the injectors off and on this injector when you rev the engine fuel ****es out but nothing comes out of the others if i do the same. so im guessing that the fuel valve in the head is blocked with this sooty crap??? if so is there any way of clearing it without removing the head, could i just simply drive it out over time with the use of redex? also am i gona cause any more damage if i keep driving with the engine in this state? what do people think, open to any suggestions... im no expert just goin of what i know.

thanks in advance for your replys chris :):)
Click to expand...

It is very usual for the injector nozzles / tips to be covered in soot, particularly more noticeable on an engine that has been over fuelling or burning oil. There is no such thing as a fuel valve in the cylinder head, the spill rail / leak off that you refer to from the injectors is controlled by the internal components of the injector. When the injection pump sends a wave of fuel to each injector, most of the fuel is injected into the cylinder but a small amount is forced into the injector body to lubricate and cool the internal components (namely two springs, a needle, and a lot of shims). There should be diesel emerging from each injector when the engine is being revved but it shouldn't be anything more than a weep. I suspect your injectors may require a service / internal clean. Have you checked to make sure that the banjos are not blocked?

-Tom
 
cheers mate, youv taught me something i didnt know there... no i havent im now gona go have a quik look.... how involved is servicing the injectors something an amateur could handle or am i better of getting it done profesionaly?

cheers
 
chris freestone said:
cheers mate, youv taught me something i didnt know there... no i havent im now gona go have a quik look.... how involved is servicing the injectors something an amateur could handle or am i better of getting it done profesionaly?

cheers
Click to expand...

No problem :)

I would strongly suggest that you take your injectors to a diesel injection specialists to have them tested. In most cases you should be charged no more than £5 per injector. They are quite straight forward, mechanical two-stage injectors. Any injection specialist should be able to check the primary opening pressures (it should be 200 BAR) and have a look at the spray pattern. They can also check for seat leakage by holding the injector just below its primary opening pressure and then exmaining around the tip of the nozzle for leakage / dripping. Ask to watch them testing the injectors so that you also get an idea of their condition. You could open them up yourself and give everything an ultrasonic clean (use a small ultrasonic jewellery cleaning bath) and then re-assemble with new nozzles but you'd have to make sure that everything goes back in the correct order. They would then require testing and setting again by an injection engineer. Expect to pay between £250 - £350 for a set of four injectors reconditioning though.

-Tom
 
Pos.. I have similair and I just fitted new recon injectors, I seem to have blowing around one of the injectors and can see the lube which I put around the injector.. any ideas ?
 
ER1C said:
Pos.. I have similair and I just fitted new recon injectors, I seem to have blowing around one of the injectors and can see the lube which I put around the injector.. any ideas ?
Click to expand...

It sounds like the copper washer has not sealed properly. Remove the injector in question and give the injector seat right down at the bottom of the hole in the cylinder head a really thorough clean. Spray a little paraffin into the hole and then use a rag wrapped around the end of a screw driver or similar to ensure that all the oil / grime from before has been removed. Peek down the hole with a torch to check cleanliness. You might want to flick the engine over on the starter one or two rotations (with the wire to the stop solenoid on your injection pump disconnected) just to blow any crap out of the cylinder that may have dropped in as you cleaned out the hole. Fit a new copper washer and make sure that it is the correct ribbed injector sealing washer, not just a standard flat washer. You should fit it with the ribbed side up towards the injector. Refit the injector and tighten it down but don't over tighten - it will seal. You might find that the injector rotates slightly as you tighten up the injector pipe - it's acceptable.

-Tom
 
Thanks POS... just to check... the ribbed side is facing the ground at the moment.. When i say ribbed I mean the bulge in the middle of the washer is that right ?

I didnt clean the base too much as they looked ok but that must be it :( I recall reading one of your posts when you had similar and cleaned it and it worked out ok.
 
ER1C said:
Thanks POS... just to check... the ribbed side is facing the ground at the moment.. When i say ribbed I mean the bulge in the middle of the washer is that right ?

I didnt clean the base too much as they looked ok but that must be it :( I recall reading one of your posts when you had similar and cleaned it and it worked out ok.
Click to expand...

You have put the sealing washer in upside down. The bulge around the middle should point up and out of the hole (towards the sky!) so that as you lower the injector into its recess, it should sit on the bulge. Then, as you tighten the injector down it compresses against the base of the nozzle cap to create a seal. The best way to put the washer into the recess is to use a tie wrap or a kebab skewer (basically something long and thin). Slide the washer up the skewer so that the bump / rib is pointing up and then lower the skewer into the recess and move it about until you feel the point pass down into the nozzle hole right in the centre. Then let go of the washer and it will fall to the base of the recess and stay the right way up. The surface of the recess needs to be really clean. If there is a bit of grit or build up it will create a high spot which will allow the compressed air / fuel to leave the cylinder.
 
Last edited:
Wow thank you, thats the way the refurb folk put it in.. I will swap them around in the morning....
 
Found the problem it was a botched refurb which had nicked the base of the injector with a spanner causing a notch which dented the washer causing the loss of gas. Reading the manual the concave side of the injector should face towards the rear of the injector.
 
Grrrr... righty you are spot on the concave side is towards the injector head... the Haynes manual is very misleading and I had them the wrong way around (the refurb folk had them the wrong way around too which I find alarming). Spraying WD40 around the injector is a fab way to see any leaks... All 4 leaked so I swapped washer and cleaned and 3 are air tight. The 4th still leaked so I did the same again and its still leaking...

I cant think what else to try I swapped to a second washer to see if it made a difference but it hasnt.
 
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