t2 -> td04 and pump adjustments = far too much smoke and poor mpg

[juz22]

hey guys,

i used to be running a t2 turbo with bosch pump, before i bought the car it had already been tuned to make 17psi and even driven hard it returned 450 miles to a tank and under hard acceleration didn't produce any smoke visible in the rear view mirror.

before christmas i had a bump and the rad sprung a leak leading to the engine overheating. i salvaged the pump and ancillaries, bought a replacement engine, td04, and a hdi gearbox. i paid a mechanic to refit all of this for me as i was too busy with work to do it myself, and after he'd fitted everything it wasn't making much power with the old pump setup (only producing 10psi) so he fiddled with the fuelling settings on the pump but i'm not sure exactly what he did.

anyway the car now makes 18psi and i've driven around 1500 miles with it like this. when the boost eventually comes on it is fractionally quicker than my old setup, however the car now pours out PLUMES of black smoke under even the slightest acceleration, so i'm not enjoying driving it as i'm always worried about blinding some poor bugger behind me. additionally, it's now only returning 330 miles to a tank compared to the 450 i was getting before (remember i've also changed from xud to hdi gearbox so i wasn't anticipating such poor mpg now)

i'm tempted to revert back to my old t2 turbo and have someone return my pump to it's old settings, but before i do that can anyone tell me does this sound like the behaviour you'd expect from the setup i have? or has the mechanic who tuned the pump just bodged it and could it be retuned to give the same boost but without wasting all this fuel?

thanks

[silverzx]

Could be a boost leak.

Is the TD04 off a working vehicle?

If its knackered it won't be burning the fuel completely leading to black smoke.

Does it smoke blue/white or anything on start up?

[juz22]

the td04 has been rebuilt so shouldn't be a problem, also used all new boost pipes, gaskets, clips etc.

there's no blue or white smoke on start up or during running, and at idle no smoke. under light acceleration there's noticeable black smoke and under hard acceleration it's just like a thick wall of black fog behind me.

[silverzx]

Over fueling then.

Turn the fuel down.

It's injecting far too much fuel too burn by the sounds of it.

Is it a bosch or lucas?

[juz22]

ok thanks, it's a bosch. i'll have a look how to turn it down.

[silverzx]

ok thanks, it's a bosch. i'll have a look how to turn it down.

It's very simple. As your looking at the pump on the right hand side above the injector line outlets is the max fuel screw. It will need turning out (anti-clockwise) to reduce the fueling. This can be found in a guide on the forum with pictures IIRC.

[Tom]

Bear in mind turning down the max fuel will affect your idle and you will have to use the idle screws or possibly the minimum throttle to bring your idle back up.

[Jimbo]

Have a fiddle with the lda on pump, get the fuel down off boost and get more higer upbthe range
There guides on here for lda setup

[anto]

Few possible issues;

How has your mechanic fitted the td04? The wastegate could be fractionally open meaning you wont be making the boost you should be.
If you haven't altered your driving style then you will just bog down due to how the td04 produces boost. You cant just mat your foot to the floor and expect it to spool like a t2.

Without knowing how your mechanic set it up its hard to know.

[juz22]

thanks for all the advice chaps. i finally had chance to read up on the various screws and have a go today.

it looks like the mechanic just wound the max fuel screw out massively hence all the smoke and poor mpg. my hot idle rpm was also 1100 before. he said that the wastegate on the td04 i bought is welded shut.

i've turned the max fuel back in a bit and kept driving it inbetween and did this until my max boost started to drop from 18psi, then i turned it back up half a turn. i then turned the hot idle screw out until my hot idle is now 900.

despite this i still get a lot of black smoke under hard acceleration. not quite as much as before, but still a fairly big black cloud. if i turn the max fuel down any more though i lose the boost.

is there anything else i can try? i'm pretty sure the mechanic didn't alter any of the lda part of the pump as it doesn't look like it's been opened up. however it may well have been modded prior to me buying the car, but didn't make this much black smoke before.

[Dave]

Thats how the pumps are, they are not very good at distinguishing on/off boost and you need to put the fuel in to make the turbo spool its catch 22, because without this it wont spool as fast. Sounds like you need to manage your right foot better.