Smoking and rough running at 2000RPM

Hi Guys

I have just spent about an hour searching and reading up on this but don't seem to get a definitive answer. My TD4 splutters and smokes (white smoke) between 2000 and 2100rpm. The rest of the time it starts and drives fine. I had a diagnostic and no faults are showing. I have read a few very long threads. The best info I can come up with from the threads is replace the wiring harness to the fuel pressure sensor? Has this cured the problem for anybody else?

Thanks for your help.

Tony

It could be several things. The fuel/sensor harness could be one of them. Injectors could be another. Low pressure fuel pump starting to give up could be another.

Thanks for the reply epi. I think I'll start with injector cleaner. it had a new LP pump about 2 years ago and the HP pump this year. I also changed the MAP sensor a few months ago.

Mine has the same issue. But much worse. Is the fuel pressure sensor. Hopefully getting it sorted this week.

HI GMC. Let me know how you get on.

Anybody else any ideas?

Anybody any more thoughts?

Disconnect the MAF and see what happens ...

When was it last serviced?

Have you tried injector cleaner or a couple of litres of cooking oil run through ?

tonyt37 said:

Anybody any more thoughts?

Click to expand...

Your TD4 rough running is most likely a dirty injector, you can prove this by running the engine at tickover and unplugging the injectors each in turn, the one that has little effect is the one with the problem, its easy to check ...

Hi i have the exact same problem... i did a leak test and showed that injector 3 is returning a lot more fuel than the others, i tried disconnecting it but the smoke is still there at 2000 rpm... The fuel sensor harness is damaged too ... I should start with the harness as it is a cheap fix.
cheers

Hi Dippy. It runs fine on tickover and perfectly smooth up to 2000rpm and under load all the way. Its when it's not pulling the problem starts. Tried injector cleaner. Serviced about 2 weeks ago inc breather's.

Malory, think i'll start with checking the wiring. The harness mod is about £40 I think. I'll try that first then the sensor. I have pm'd somebody who had exactly the same to see if he managed to cure it but he hasn't posted for a bit. that may be good news!

Bad news... Seems like it's an injector issue for sure dont remember how many times now i've changed faulty ones... tho it's 300k km now
edit: will post back if problem solved...
@tony: have you done a leak back injector test?

Hi all ,
finally problem solved it was the turbo solenoid.
the smell of unburnt gas is caused by a lack of air.
thx

sorry to side track but how much have u guys paid for ur injectors please

assume they were on a reconditioned basis

is £100 each about right plse

thks guys

Bosch recon units with 2 year guarantee 110 plus 30 back exchange when you send old injectors back local Bosch franchise

Well I got a 2nd hand Turbo Solenoid from ebay and a bottle of injector cleaner. Bingo!!! Sweet as a nut. Not sure which cured it but it's fixed for now anyway. I sat with my foot on the accelerator ar 2000rpm for 5 mins and it didn't miss a beat. Cost to fix £22.

was that the turbo vacuum solenoid with the 3 or 2 pipes on?

The one with 3 pipes on it.

I'll tell my mate today as he has spent hundreds of pounds trying to sort the same problem out

malory16 said:

Hi all ,
finally problem solved it was the turbo solenoid.
the smell of unburnt gas is caused by a lack of air.
thx

Click to expand...

tonyt37 said:

Well I got a 2nd hand Turbo Solenoid from ebay and a bottle of injector cleaner. Bingo!!! Sweet as a nut. Not sure which cured it but it's fixed for now anyway. I sat with my foot on the accelerator ar 2000rpm for 5 mins and it didn't miss a beat. Cost to fix £22.

Click to expand...

Evening all, long time coming this post but ive been working my way through along list of trying to eliminate the lumpy/smoking symptoms you both had at 2000 rpm. Lastly I decided to stump up the cash and get the injectors reconditioned thinking that they were the root cause. After a nightmare getting them out as 2 were seized solid and i had to fabricate a puller, all 4 were found to be well out of Spec and have been refurbished by bosch. Great I thought all fixed, well no unfortunately it still does the same and then I found this thread. I'd already ruled out the boost control solenoid after replacing a vacuum hose and testing the vuccum pump. I can see the turbo actuator arm physically moving in and out in relation to the throttle being depressed whilst stationery but I'm wondering if I overlooked something as this was such a sure fire fix for you both. Do the solenoids act differently under load, had your solenoids packed up completely?
Thanks in advance
Damian