hi gents, i am having a few issues with my 03 1.9 sdi.130k. sometimes when you start it up it revs up somewhere between 1000 rpm and 1500 rpm it then coughs and settles back to about 950rpm on tickover. now when this is occurring i am running under powered just like i can only use the first third of the throttle. if you put your foot down you get no more power than just using the top third of the throttle. Now this had happened before and it just cleared itself and i carried on. so yesterday i though i would change the fuel/ air filters and put some diesel cleaner through the system. after doing this the car ran perfectly for about 25 miles until i re started it at a garage and on starting the revs went straight up to about 1250 rpm and then drove underpowered again. i have recently changed the stop solenoid on the fuel pump as well.

 

can anyone shed any light on how the throttle works and wether this could need cleaning?

 

or does anyone have any ideas of what to do next?

 

Thanks in advance, rob.

little update- when i got home i took the laptop (vcds lite) out to the car to try and read the codes (if any). And it threw up p1537 which is faulty fuel shut off solenoid. ok you might think but i have just replaced this part so not so likely right?

So i cleared the code and took it for a spin and full power restored!!

The only issue i have now is why is it throwing up the code if the solenoid is good? could it be a wiring fault as these tend to be common on these especially at this milage?

It also showed n109 in the fault code reading does this have any meaning?

tia rob.

N109 is the fuel shut off solenoid

We're the codes cleared when the valve was replaced?

yes they were.

is the n109 the relay for the solenoid ?

Edited 28 January, 201610 yr by robmajor

Possible wiring issue then. Could do with the VW fault code and its matching description, might help.