2.5 TD running rough after re-build

[Graham2]

Evening all, I've just put new rings, big end shells etc in a 2.5 turbo diesel 110 Hi Cap. I bought it cheap, to do up in lunchtimes at work. It ran OK but was breathing heavily, so I thought new rings etc would help. I know I should put a 200 tdi in it, but the idea is to run it for a while, then put a 3.9 V8 on gas in it. No point going tdi anyway, as in 2 years Red Ken will charge me £200 per day to drive it out of the garage!!! The head went back on well, with recon injectors, new glow plugs etc. It started second turn of the key, but runs very badly, rather like a petrol 4 cylinder with 2 leads on the wrong plugs. Fuel system was bled, but it won't rev and I get a huge cloud of white smoke (un-burnt fuel?) from the exhaust. Valve clearances are OK and both steel and copper washers are on the injectors. The fuel pump has not been touched during the top end re-build, but could this be the problem anyway? Would the extra compression from the new rings and re-ground valves be causing it? I thought I was doing the engine a favour. Any ideas anyone?

[ian_s]

i know i might be a tad cynical, but you say you put recon injectors in, do you still have the old injectors?
my first thought was your injectors not atomizing the diesel properly, then i re read what you wrote, and that stuck out like a sore thumb!
i always question the 'new' parts i fit if something isnt working like it should.
do you still have the old injectors? if so, refit them and see what happens

[Graham2]

Thanks for the reply, but I re-fitted the old injectors, and it was still the same. When I try to put my foot down to move the thing back into the garage, it has very little power, and chucks out tons of white smoke. If I loosen an injector nut to try and bleed any air out, the engine stalls, which it didn't do before the re-build.  Maybe I should mark the fuel pump, and try adjusting it to see if it makes any difference. If it does, it would suggest the fuel pump timing is out, but I haven't altered it?! Is this the only thing worth trying? I don't really want to pull the head off again...

[LeanneNCharlie]

hi. another possibly silly question but its worth a stab at. did you put the push rods back in in the same order they were removed? or fit new ones? did you reset the tappets when you put the head back on? only asking because when i rebuilt my 300tdi head i didn't reset them,(silly i know!) just put them in and away we went. it was very very sluggish and took some effort to start. turned out the exhaust valves were not closing fully so loosing compression. reset the tappets and it flies now, as much as a diesel will anyway!

even after rebuilding our 90's td engine it still smokes 40 a day when cold. so add this to valve clearance and it could be similar to what you are suffering.
set the clearances to 0.2mm for both inlet and exhaust.

hope this is of help.

charlie.

[Graham2]

Tappets are set OK, double checked them. I've tried turning the fuel pump a bit, and it's made it a fraction better. It ticks over a bit better, not jumping about so much, but still produces its own cloud when revved. I can only put it down to the timing belt slipping on a sprocket, meaning the fuel's being squirted in at the wrong time, causing the un-burnt diesel to come out as white smoke. I've ordered a new belt, but the nut on the end of the crank doesn't want to come off. I think a 3 foot length of scaffold tube is the answer!

[Tommo]

the starter motor holds the key to undoing that nut.

[Graham2]

A guy I know has advised putting a long extension on the socket, and jamming it against the ground or chassis, and then trying to start it. He says the nut will come undone. Is this what you mean?

[ian_s]

that sounds like a recipe for disaster, but my well do the trick

if you do it, take the wire off the fuel cutoff solenoid, so it wont actually start

[Graham2]

Well, after much agro with a 4 foot length of scaffold pole, it still didn't shift, so [!Expletive Deleted!] or bust time! Wedged the breaker bar on the chassis, took the wire off the fuel pump and turned the key. Off came the nut, first time! No wrecked starter or ring gear as far as I can see, just a loose nut. The timing cover's coming off tomorrow, so hopefully, I'll find the belt on one tooth out, put the new one on properly and Bob's my uncle. I hope it runs better, without ticking over like a pig with the huge cloud of white smoke when I rev it. If all's not well, I'll have to take the head off again to see what else it could be. Fingers crossed!

[Graham2]

Timing cover came off, and all the dots line up, damn! Pump timing is perfect too. Next possibility is the diaphragm could have perished in the gizmo on the side of the pump, the one that controls the turbo boost as revs rise. There was diesel in the thin pipe the other day, so maybe the turbo's getting fed fuel it shouldn't? All this extra fuel could be causing the cloud of white smoke and the rough tickover. I'll see about getting a replacement diaphragm tomorrow, here's hoping...

[Les Henson]

If you have fuel in the wastegate pipe, then the diaphragm has split. When this happens you usually get pressure in the fuel tank as well. The diaphragm can be changed without taking the injector pump off the engine.

 

The diaphragm is a Delphi item and is part number 7243 - 006 and is available from most diesel specialists.


Les.

[trickydicky]

i have been folowing your progress sins you first posted it. i have been having exactly the same problem and have done everything that you have and the same as you i havant had any luck i even had the pump set. so now i am in the same boat as you do you mean the diafram whith the security tab on side of the injector pump or do you mean the lift pump?

[Graham2]

I spoke to a company in Leeds yesterday, and the really helpful guy there says pretty much the same. Yes it is the thing with the lockwire on it, on the side of the fuel distributor pump. It costs £12.88 for the part with the diaphragm in it, which is a bit of a result. The only trouble is that I can't get a socket or a spanner on the bottom nut. The top one is easy, but I'm at a loss as to how I can get it undone. Taking the pump off seems to be the only answer, but to get it off, the oil filter housing has to come off to get it out. I'll have the whole Landy in bits soon. Oh well, the High Cap only cost me £500, which is what I sold my wheels and tyres for, so I'm kidding myself it was free. I know the 200 TDI's better to drop in, but in 2 years time, TFL will charge me £200 per day to drive it, so a 3.9 V8 on gas will go in before then.

[Graham2]

Got it of!!! Well chuffed, but it was a real pain, as I had to get into some odd positions to be able to get it undone. The centre of the diaphragm was completely detached from the centre piece, so now wonder the engine was running so badly. I may empty the fuel tank completely, as it has red diesel in it (it was on a farm) and god knows what else. I'd rather fill up with stuff of a known quality in case there's something dodgy in there that could rot the new one. Bloke at Sewells talked me through adjusting the pin before it goes back in, sounds easy, but it could be fiddly getting the cover on without the springs popping out. I can't wait to get it fixed, so that I can see how the engine runs after the re-build.

[trickydicky]

i disconected the pipe going to the turbo today and it still smokes on startup so it carnt be that for me i was thinking of changing the lift pump what do you think?????

[Graham2]

Not sure, as this is my first diesel engined vehicle. Maybe yours just smokes a lot till things get warm. Maybe your pump is knackered, it's worth checking out the diaphragm though, but if you can't get it back together, don't blame me! There's a couple of springs in there that look like they could be a pain to get back in right. Probably easy on a bench, not so easy when still fitted. I just hope it cures my problems.

[Graham2]

Fitted the diaphragm, put timing cover etc back on, started after 2 or 3 turns of the key. Ticks over better, but not as nice as before the re-build, but still tons of white smoke when it's revved! I'm completely stumped. The diaphragm's working, as if I suck on the pipe, I can hear the pin in the side of the pump move (and I don't get a mouthful of diesel) HELP!

[trickydicky]

try the lift pump i havnt done myn yet but i heard if its on the way out it can suck in air back from the tank but who knows i have been listning to good advice for about 12 months and it has only cost me money the lift pump is my last hope. good luck and keep me posted as i have the same problem

[Graham2]

I bled the pump and no air was coming out, just fuel, but if I loosen an injector nut on any of the injectors, the engine stalls. The engine should still run even on three cylinders, as it's the way to test for a dodgy injector. Maybe air's getting into the system somewhere as you say. The chap at Sewells Of Leeds says white smoke is a symptom of too much air. He suggested  that I have a container of diesel with clear plastic pipe from it to the lift pump, and another bit from the return pipe on the injectors. This then does away with the tank and the associated pipework. I'll give it a go after the bank holiday and let you know how I get on- just hope it's good news!

[trickydicky]

WOW LOOK WHAT I FOUND MATEY        READ THIS THEN           if you find the power is very high but you have lots of black smoke
from exhaust at all ranges , undo the fuel metering screw on rear of
pump and go out 1/4 turn at a time until smoke dissappears .
youll have to strike balance between power and smoke and so it may take
a few attempts to get satisfactory .

this screw is on rear of pum near the injector pipe unions , it has a
13mm locknut and a screwthread extending out about 25mm , there is
screwdriver slot in end of thread , you hold locknut loose with spanner
and then unscrew or screw the thread in or out as desired .
IN for more fuel, OUT for less .

the "smoke adjuster" is on top of pump housing,there is a small [gold]
blanking cap [15mm dia] on top of casting  which has the 4 screws in ,
pry cap out with screwdriver and youll see 13mm locknut with a 8mm TORX
grub screw , this screw is screwed in for more fuel and out for less ,
locknut may be loctited and so might need a bit of effort to undo .

inside pump, under top casting , ie the housing on top of pump which
has 4 screws holding it down , is a diaphragm and shaft and a starwheel
adjuster which alters fuel delivery rates .

the metal plate holding rubber diaphragm has a dot mark on it and the
diaphragm can be rotated to change fuel metering rates , this will be
pointing somewhere between 12 oclock [to rocker cover]  and 6 oclock
[towards wing ] , the leanest position is towards rocker cover and
richest towards wing .

just take it that youll position it somewhere from 12 oclock to 6
oclock , it does not screw in and out but rotates around a 360deg axis
.

you can pull the diaphragm assembly out by hand , in one piece with
rubber and shaft attatched .

on shaft youll note a  tapered and eccentric shape of shaft , this
rests against a pin down in the pump itself and alters fuel rates
according to position the taper or eccentric is in .

the turbo boost pressure is applied upon diaphragm via pipe on side of
top housing and thus pushes shaft down using the diaphragm , allowing
pin in pump  to come in and allow more fuel thru as revs and boost
pressure increase etc .

under diaphragm youll see large spring , this is just placed in there
and can be removed/reinstalled easily .

under spring youll see a starwheel adjuster , this has a click stop
adjustment and if you pry the lock spring using screwdriver you can
rotate the starwheel .

to lessen spring pressure effect of starwheel you will screw the
starwheel in clockwise , but only about 1/2 turn at a time and noting
smoke from exhaust [under load] after adjustment .

to lessen spring effect you undo the starwheel .

this starwheel alters the spring pressure against the diaphragm and
alters where the turbo boost is allowed to move the diaphragm downwards
to increase fuel flow .

basically only minor adjustment of starwheel should need to be made ,
if any adjustment .

there is a white nylon spacer on the metering shaft and dont forget to
make sure it is still fitted when refitting metering shaft/diaphragm
and spring assembly , as it stops length of travel of metering shaft .

the main adjustment that makes most difference is the full load
adjustment on rear of pump , if unscrewed too far youll note lack of
pull when in top gear at low [25mph ] speed when on flat road .

hope that is easy enough to understand.

ive been adjusting my pump for maximum economy , so all my adjustments
have been in reverse .
previous owner screwed everything IN , yes it went like stink but i
only got 23mpg locally and lees on motorway driving .

cheers , ian .

.

[Graham2]

I've got a feeling this is for 200 TDI engines

[trickydicky]

checked it out and yes it is ITS A BLOODY GOOD JOB I DIDNT DO THET THEN

[trickydicky]

--------------------------------------------------------------------------------
i am still eagerly awaiting to see if the pump thingy worked i take it it didnt then o well its back to the drawing board then

[Graham2]

Right then, update time. I've been phoning round and everyone said it would be the distribution pump or the timing. Timing's perfect, so maybe the pump's duff, but why would it be if it was OK before the engine re-build? Next theory was that I might have bent some pushrods when I tightened down the rocker shaft. So, off came the rockers- all pushrods OK. Damn! Pushrods are only a couple of quid each, so it would have been a nice cheap fix, but no such luck... I then thought I might as well take the head off again and check for cracked pistons or head. When I took the silicon turbo to inlet manifold pipe off, I noticed diesel in the inlet manifold. With the manifold off I could see loads in there, and the exhaust manifold was oily and black on cylinders 2 and 3. It now looks that when the turbo boost diaphragm on the side of the distribution pump was knackered, it fed tons of fuel up the turbo boost pipe into the turbo. This then went into the bottom of the inlet manifold, and was being sucked into the chambers. There was obviously far to much fuel about to burn, hence all the white exhaust smoke! Maybe if I'd been able to let it run for ages with the new diaphragm installed, it would have burnt away, but with the amount of smoke it just wasn't an option. I hope that when the head's off tomorrow, I'll see 4 pristine, un-cracked pistons, but loads of excess fuel about and black sludge. Diesel has probably contaminated the engine oil, so that'll need changing, and the valves will need cleaning up, but fingers crossed that's all it'll be. Oh well, here's hoping...

[piggysteve]

Good luck, at least you've found something.

[Graham2]

Head off at lunchtime (the engine's not mine) and no cracked pistons, which was nice. Head seems fine, so it looks like it was all that extra fuel sloshing about trying to burn. The tops of number 2 and 3 pistons were very black, which was expected as the 2 and 3 exhaust ports were black and sludgy. So, hopefully it'll all be ok when I get the head back on with a new gasket. I can't wait to get it done, to see if it runs like it should.

[trickydicky]

what do you mean all the extra fuel sloshing about were was it cumming from? by the way i changed the lift pump which was easy to do but what a difference. not at first but after about 40 miles or so it now has more power seems to be using less fuel and a lot less smoke on startup because the engine now starts easier.not brilliant but a lot better. it will be good to hear what you have found since we last spoke.

[Graham2]

When the turbo boost diaphragm on the fuel distribution pump was perforated, it allowed fuel to be sucked up the pipe and into the turbo. The diesel then got forced into the alloy inlet manifold, where it sat in the bottom of the horizontal tube. It was being sucked up into the cylinder head when the inlet valves opened, mixing with the fuel squirted in by the injectors. There was obviously far to much fuel to burn, and the excess came out as thick white smoke. There was about 1/4" of fuel in the inlet manifold (which should be dry!) so if I re-build the top end, everything should be sweet as a nut. Well, that's the theory anyway. Only time will tell I suppose, but here's hoping! I'll let you know how I get on.

[trickydicky]

sounds good but i think i would bust mine if i tryed that

[Graham2]

Well, the head went back on on Monday, followed by the injectors etc. Then on went manifolds and turbo. With all the other bits sorted today, it started! Bit of white smoke, but that's to be expected, what with all that unburnt fuel sludge to burn off in the exhaust. I should be able to get it out of the garage for the first time in weeks tomorrow, and give it a bit of a run round the field. I'm REALLY hoping that this has sorted it once and for all. I'll re-do the tappets and fuel pump timing first, just to make sure everything's as it should be, but it could be near the end of this long running saga... I just want to drive it!