Thread: Does this look like the right stuff? (EGT)

Originally Posted by Blknight.aus

on a similar topic...

one of the guys at work bought in a nissan with very similar symptoms.

turns out that the boost compensator plunger had gotten stuck in the full down position meaning that the engine had max fuel available all the time and the turbo was somewhat rooted not making full boost. Smoked like a chimney unless the loud pedal was used gently.

Thats the only thing about mine though is it doesn't smoke

well it does on start up and I get a small puff when flooring it but then it runs ok.....its literally when the car is going up the steepest part of the M4 coming over the mountains its on the steepest bit in third it starts to lose speed quickly then then at 3000 it kicks down too 2nd and the smok just ungulfs the entire road. I guess all I can do is ask the garage to back it off a fraction..either that or be prepared to climb that bit of road at 40..

thats the stupid thing about it love the way the car is running at the moment on road got much better response its quick off the line can happily pull out and over take on the motorway without having to really think about it and plan it between gaps...this is the bit I don't want to loose. but I guess I have to if I don't want to do risk premature wear and do a head gasket.

that can also be a symptom of a sticking advance unit along side of overfueling.


If the injection timing doesnt advance at high engine RPMS you can wind up not buring all the fuel. on a standard pump setup it usually turns up as a slight loss of power with smoke at full noise. with an overtweaked pump it shows up as buckets of smoke.

Originally Posted by Blknight.aus

that can also be a symptom of a sticking advance unit along side of overfueling.

If the injection timing doesnt advance at high engine RPMS you can wind up not buring all the fuel.

on a standard pump setup it usually turns up as a slight loss of power with smoke at full noise. with an overtweaked pump it shows up as buckets of smoke.

how can that be rectified?

It may also pay to get the injectors pattern checked but back to the point if thats what it is and not just a case of plain old overfuelling.....

overhaul the pump.

Originally Posted by Blknight.aus

if thats what it is and not just a case of plain old overfuelling.....

It may also pay to get the injectors pattern checked

overhaul the pump.

mmm that sounds expensive.

I would say its a case of over fuelling only because I never had a problem before the pump was changed after the timing belt was done

It probably wouldn't hurt to advance the timing a little.

JustinC recommends this for the 300Tdi - he has posted several times.

From memory (but don't trust mine after so many sleeps) I think he recommended 0.3mm plunger lift.

so would that be advancing the timing on the injector pump? I wouldn't have a clue ow to advance timing neither would Ian.....

just can't afford to put the car in the garage at the moment just for a tickle

Originally Posted by dullbird

Thats the only thing about mine though is it doesn't smoke

well it does on start up and I get a small puff when flooring it but then it runs ok.....its literally when the car is going up the steepest part of the M4 coming over the mountains its on the steepest bit in third it starts to lose speed quickly then then at 3000 it kicks down too 2nd and the smok just ungulfs the entire road. I guess all I can do is ask the garage to back it off a fraction..either that or be prepared to climb that bit of road at 40..

thats the stupid thing about it love the way the car is running at the moment on road got much better response its quick off the line can happily pull out and over take on the motorway without having to really think about it and plan it between gaps...this is the bit I don't want to loose. but I guess I have to if I don't want to do risk premature wear and do a head gasket.

You have many different cases there.

1.

it does on start up

This is normal - while the engine is cold it can't burn the fuel completely.

2.

a small puff when flooring it but then it runs ok

This is most likely because the fuel is turned up and the turbo boost is low. The boost pressure rises as you accelerate to provide enough air to burn the fuel. Not worth worrying about - you could turn fuel down and accept performance loss, or fit a variable geometry turbo.

3.

going up the steepest part of the M4 coming over the mountains

See previous posts. You have too much fuel or not enough air. The turbo should be producing maximum boost in this case. Either the boost pressure at the inlet manifold is not what it should be (then fix the air problem), or the maximum fuel adjustment on your pump is turned up to high (adjust pump). I think if it was faulty injectors or timing advance mechanism in pump, you would make smoke in other cases.

4.

on road got much better response ... can happily pull out and over take

In these cases your turbo will not be producing maximum boost. This is a different fuel adjustment of the boost compensator on the pump (not the maximum fuel adjustment).

5.

its quick off the line

The turbo is producing little or no boost. This is a different fuel adjustment again of the boost compensator on the pump.

The maximum fuel screw is on the rear of the pump near the fuel lines that go to the 4 injectors. If the mechanic adjusted this screw, it should be backed off. If the mechanic did not adjust this screw and it is in the stock position, then the rotation adjustment of the fuel pin needs to be changed to reduce the fuelling at maximum boost.

Your performance off the line (5. above) and at low boost (4. above) don't have to suffer. These are 2 different adjustments of the boost compensator to maximum fuel.

If the maximum boost, fuel pin adjustment is reduced, this will also reduce fuel at no boost and at low boost. This is why I gave ( in an earlier post) the order that the boost compensator should be adjusted.

Get the maximum boost fuel correct first. Then adjust the compensator for low boost fuel, then adjust for no boost (3 different adjustments of the boost compensator). As I also said most internet posts about adjusting the boost compensator have the order ar.. about.