hello all
im new to the forum and i hope i can help you as much as you can help me.

i have a disco 1 300tdi manual and its blowing a lot of smoke while under load and a fair amount while just cruising and need help finding out why...

when i got the car i was told that the injector pump was tweaked but that's about it, iv stopped driving it as i feel bad about the smoke coming out of it so i am here today to ask if anyone here knows how to adjust the injector pump back to stock and if there are any other problems that could cause the smoke.

1. injector pump has been adjusted to unknown specs
2. gets about 500 k's to a tank
3. engine sound like its about to blow up at about 3000 rpm and does not like going past 2500.
4. boost is about 15psi
5. running 32's
6. has not over heated while i have had the engine
7. i installed the engine into the current disco.

if you need more info please ask


i also have a spare injector pump and am also wondering if there is a tutorial on how to swap them as the spare pump was just undone and taken off another engine so i don't know if it was meant to be set to anything before removal.



thanks for what ever help you have for me.

Hi, 500k to a tank aint much at all, my tweaked up 200Tdi running 32s returns at least 700 when working hard and as much as 900 when pootling about.

Where are you taking your boost reading from? Manifold or the little pipe that goes to the wastegate actuator?

There are loads of guides to tuning the pump, have a little forum search for one of the many, then follow the instructions but in reverse if that makes sense.

Welcome to the forum ..

The problem is how was it tweaked?

I'd do a search on the forum for tweaks, there are a couple or so that can be done, so find different ones and try to apply them to your motor. Most of them suggest tweaking till there's a small amount of smoke and reduce slightly ... many feckwits think more smoke means more go, usually it doesn't.

I basically service it too, take the pump back to standard, timing to standard etc etc and try to get it running as standard. Trying to 'fix' what others have done is often quite hard to do!!

I replied to your intro post.


Cheers

dieseldog69 said:

Hi, 500k to a tank aint much at all, my tweaked up 200Tdi running 32s returns at least 700 when working hard and as much as 900 when pootling about.

Where are you taking your boost reading from? Manifold or the little pipe that goes to the wastegate actuator?

There are loads of guides to tuning the pump, have a little forum search for one of the many, then follow the instructions but in reverse if that makes sense.

Click to expand...

im getting the reading from the boost gauge that goes to the pipe that goes into the injector pump.

An interesting read.

Cheers

neilly said:

An interesting read.

Cheers

Click to expand...

Makes my head hurt just reading that

Just to be sure what colour is the smoke? Is it black?

James Rogers said:

Just to be sure what color is the smoke? Is it black?

Click to expand...

from what i can see its black but im the only one that can drive it as no one near me can drive a manual lol

ok so i adjusted the Diaphragm from about 11 to 7 as the marks on the cone looked like it had only been adjusted once so i set it to the previous...

i did not adjust the star wheel or the screw as i don't understand what exactly to do but if i recall correctly the star wheel is to set when the boost kicks in????
i don't understand what the screw is for.

now as i have only done the Diaphragm will me not adjusting the others do any damage?

The PDF neilly put up is great for explaining what all the functions inside the compensator housing do and are - worth reading for this, but the basic gist is:

The top diaphragm is attached to the cone / boost pin underneath. It has an eccentric slope on the cone that rides the compensator pin - if you pull it out (it should come out very easily, don't force it if not) - you will probably see a very noticeable wear mark and a less noticeable one - first thing is to mark with a pen on the top of the diaphragm where the bigger wear mark is, as this is probably the stock position. This assembly controls how far the compensator can move, and the fueling characteristic of the curve. There should also be a nylon sleeve below the pin, to limit the overall travel but no doubt this has been removed and lost already. It is possible that the pin has been changed for an aftermarket one, mind you which are a fixed profile rather than concentric cone that can't really be changed but turning them. (but provide much more fueling overall)

The star wheel is there to seat the spring, which applies load to the diaphragm - think of it as the spring in an accelerator pump on a carb if that helps - it controls how much boost is required to overcome the spring tension and enrich fuelling, turning the star wheel clockwise will reduce preload and turning it anti-clockwise will increase preload - if it has never been marked when previously moved it is a little tricky to return to standard. I'd say turn it 180 degrees anti-clockwise to start, also if memory serves the spring should protrude 16mm from the mating face of the top of the compensator housing, if it measures 15.5mm or so someone has adjusted it before (but don't take that as gospel, might just be the spring is more worn that the one I've measured)

Top screw is the stop screw for the whole assembly, short explanation is it increases off boost fueling marginally for each turn clockwise and reduces it for each turn anti-clockwise.

There are other screws and stops that may have been adjusted, and if it really belches black smoke - especially at idle and light low speed part throttle and struggles to rev freely the problem is probably not merely down to past adjustments.

A video of what it sounds like would be handy, especially the sounds it makes up the rev range.

how odd...
i wasn't sure if my adjustment would damage it so i put it back the way it was at the start.......and now there is a lot less smoke then before.

could i have unjammed something?

Original post said 500k per tank, as he is in Australia that would be kilometres, about 320 miles.
Not good. Have you tried fuel additives to clean the system? I use 2SO in my Td5 and guarantee there is NO smoke whatsoever.
Different engine i agree but anything is worth a try.

god i wish i knew someone that would change the injector pump for 2 cases of beer or something......mechanic wants around $800 to change it and about $650 to tune it.

Landy McRover said:

god i wish i knew someone that would change the injector pump for 2 cases of beer or something......mechanic wants around $800 to change it and about $650 to tune it.

Click to expand...

Pay my airfare

If you were me, I'd figure the one on it now at least runs ... so remove it and replace with the spare one and see what happens.

If the replaced one runs OK then use that and use the one taken off to play with and understand what it does, then have a go ar rebuilding it using the workshop manual or if you can get it the actual pump instruction manual!

Let's face it, you ain't happy at how it runs, you ain't sure what to do but doing something (logically) with the pumps might spark something and get it to work. Right now it's broke, but runs, and playing with the spare pump won't tell you anything unless you've already changed them and seen which runs best, I reckon. Keep the known running one set as it is for now. You never know, just replacing them and setting timing etc might help all on it's own!

Good Luck ..