Black smoke after pump rebuild

[reetp]

So finally found the cause of the diesel pump leak on my 2.7 TD was the pump seals. Wondered if it may have been started by some dodgy fuel the local Repsol garage had several years ago - they paid for a tank clean out etc etc but often wondered if it did anything else.

Pump was fitted with new seals and it runs sweet as now. All filters and oil changed at service a couple of weeks ago.

All OK except for a lot of black smoke, especially when at lower revs. Never used to be that bad before.

Once you hit 2800 rpm or so and the turbo starts powering in it seems fine. If you use about 2/3 throttle you can feel the turbo come.

No other issues, juns smooth. Just the smoke - and I guess a lack of power - embarrassing as I chug uphill try to get the revs up whilst leaving a smoke screen a WW2 destroyer would be proud of behind me! Anyone would think I was shovelling coal into the furnace!

It's passed the ITV (MoT here) yesterday, amazingly, but I'd like to understand why she's a chain smoker and try and reduce it a bit if possible. My mechanic mate and the pump company were 'well it passed - no worries' !!

First guess is clean injectors?

After that my next guess would be insufficient air at lower revs - something with the turbo?

All your fab suggestions appreciated as normal!!

B. Rgds
John

 

[solarman216]

Well if it has passed your equilivent of our MOT I am surprised it is not exhibiting some signs of poor performance, but of course I do not know what your MOT criteria are, from your description I would guess the turbo fuel compensator is poorly adjuster, but need more info to confirm this, Rick

 

[reetp]

Well if it has passed your equilivent of our MOT I am surprised it is not exhibiting some signs of poor performance, but of course I do not know what your MOT criteria are,

Stricter than the UK on some things, loser on others. But they are independent stations - no vested interest in passing or failing you. All they do is test. It's quite good actually!

Performance hasn't really appeared to change much - it was leaking quite well before!!

The one bit I would have said is the low rev acceleration under load/uphill. Top end is fine - had it pretty well on the rev limiter in 5th down the motorway the other day trying to give it a clear out. Sweet as!!

But it dogs (and smokes more than I used to) in 2nd as you accelerate until the turbo kicks in.

from your description I would guess the turbo fuel compensator is poorly adjusted, but need more info to confirm this, Rick

From a quick read up on it, it sounds like the perfect culprit.

What info - pump type I presume? Think it is a Bosch but need to check.

Anything else? This is a 2.7TD SE last of the square headlamp, no MAF or intercooler version.

(This is really a continuation of this original post but it was some time ago
http://www.nissan4x4ownersclub.com/forum/showthread.php?t=29508)

 

[solarman216]

OK no MAF or intercooler then the pump is mechanical, from the turbo there should be a small hose to the diaphragm chamber (compensator) on the top of the pump, it would be good to put a tee into this line and run a pressure gauge so as to monitor pressure while driving, a 0 to 20 psi gauge would be good, there could be all sorts of issues here so lets start with what the turbo puts out at varying loads and engine speeds, Rick

 

[reetp]

OK no MAF or intercooler then the pump is mechanical, from the turbo there should be a small hose to the diaphragm chamber (compensator) on the top of the pump, it would be good to put a tee into this line and run a pressure gauge so as to monitor pressure while driving, a 0 to 20 psi gauge would be good, there could be all sorts of issues here so lets start with what the turbo puts out at varying loads and engine speeds, Rick

OK - sounds like a plan to me.

I need to find a gauge but I can sort that. Might take a few days as it is August in Spain and lots of places are shut!

I'll check the pipe and get some pix too.

I'm sure they missed something when they hooked it all back up.

Many thanks!!

B. Rgds
John

 

[solarman216]

OK wait to hear with some numbers, Rick

 

[reetp]

Couple of pix

 

[reetp]

This pipe I think?

Looks a bit flaky at the top. Might renew anyway. Any particular type?

While I think - any recommendations for a pressure gauge?

 

[solarman216]

Yes this pipe pointed with your finger should go to the domed structure in your first pic but I cannot see it, the frayed bit is just the protective braiding, you need a tee piece the same external diameter as the internal diameter of the pipe and a bit of pipe long enough to get into the cab, as for gauge a 0 to 20 psi gauge would be best, if you go for 0 to 50 you will struggle to see the lower pressures as the absolute maximum you will see is 15 psi, Rick

 

[solarman216]

After re reading this thread I think it could well be the turbo which is at fault, but gauge in that boost line will confirm it, Rick

 

[Banshee]

Yes this pipe pointed with your finger should go to the domed structure in your first pic but I cannot see it, the frayed bit is just the protective braiding, you need a tee piece the same external diameter as the internal diameter of the pipe and a bit of pipe long enough to get into the cab, as for gauge a 0 to 20 psi gauge would be best, if you go for 0 to 50 you will struggle to see the lower pressures as the absolute maximum you will see is 15 psi, Rick

I like the Tefen stuff for that

https://catalog.tefentech.com/catalogue/group/15191/Barb Connectors (Agriculture Tube Fittings)

 

[reetp]

Yes this pipe pointed with your finger should go to the domed structure in your first pic but I cannot see it,

It does - I did look.

the frayed bit is just the protective braiding,

OK. As a thought, possible leak?

you need a tee piece the same external diameter as the internal diameter of the pipe and a bit of pipe long enough to get into the cab, as for gauge a 0 to 20 psi gauge would be best, if you go for 0 to 50 you will struggle to see the lower pressures as the absolute maximum you will see is 15 psi, Rick

Yup - finally got one ordered coming Friday I hope.

[Quoe]After re reading this thread I think it could well be the turbo which is at fault, but gauge in that boost line will confirm it[/QUOTE]

Joy :-(

It wasn't noticeable until the pump was rebuilt a month or so back. It was leaking quite well - seemed to be the seals. Performance was never great - they never are - but not significantly smokey.

Old girl has plenty of go - top end seems fine. You can feel the turbo come in around 2800 rpm at 1/2 or 2/3 throttle.

Just the low end. The compensator would make sense.

 

[solarman216]

When they rebuilt the pump, compensator parts would also have been checked over and presumably the whole thing set up on a machine, but we will see what the gauge shows once it is up and running, Rick

 

[reetp]

How do you like my boost gauge?

 

[reetp]

Seems sturdy enough. No digicals beyond the light.

Feel like a true Vice Grip kinda guy ;-)

 

[reetp]

And some videos here. Hard to drive and video AND wave to the policeman going the other way

https://esmith.impamark.co.uk/Terrano/

Even on the cheapo gauge it seems about 10-11 psi

Images attached is the end of the pipe where it connects to the manifold.

Think that is toast as the rest is hard as nails.

Seems a bit lest smokey after I cut that off and added the gauge. Probably psychosomatic.

Think it is worse after a bit of low speed trundling around.

 

[reetp]

Direct video links (it is my server - it won't bite!):

https://esmith.impamark.co.uk/Terrano/20220818_133541.mp4
https://esmith.impamark.co.uk/Terrano/20220818_133749.mp4
https://esmith.impamark.co.uk/Terrano/20220818_134001.mp4
https://esmith.impamark.co.uk/Terrano/20220818_134136.mp4
https://esmith.impamark.co.uk/Terrano/20220818_134647.mp4

 

[solarman216]

I am going to need some quiet time on my own to go through those vids with sound, get back to you when I have done so, Rick

 

[solarman216]

Initial response is your turbo is coming in very late, you should be seeing boost at less than 2k revs, Rick

 

[reetp]

Initial response is your turbo is coming in very late, you should be seeing boost at less than 2k revs, Rick

OK - any specific driving you want me to do to test that a bit more?

I just a did a quick spin here & there for a bit without any real direction - I can do something specific if you want - accelerate slower/faster etc. I can get my mate to video or drive.

Also, the gauge is not a top quality job....

As far as turbo/fuel compensation if there is less boost it should be less fuel nonetheless?