Slight Hesitation

[djmx5]

Hi All,

I've now had my 2005 1.9tdi estate for two months and at last have got chance to give it it's legs on a trip to Wales. Up and down the montains and valleys and along the coastline of Mid Wales it has been fantastic. Carries the family and all our stuff, pulls very strongly and still gives me better than 50mpg. I'm very pleased to say the least.

One thing I noticed yesterday during a 280 mile journey was a very slight hesitation like a momentary interuption of the fuel supply that only occured when having come off throttle and re-applying very gently, that is to say 'feathering' the gas pedal. This does not happen when given a modest amount of throttle or a 'boot full'. It is almost imperceptable.

I did notice the same 'fault' -if that is the right word- with our old Audi A3 1.8 petrol but it never developed further than as previously described during its 110k miles.

Anyone any ideas?? The Passat is almost 43k miles now.

Okay thanks.
D

[martin1810]

You could get a code read to see if anything has registered or just leave it and see what happens. When did it last have the air filter and fuel filter changed. They are cheap things to try.

[djmx5]

Thanks Martin, last had new oil and filters approx 2k ago when I bought the car in Feb, the dealer serviced it.

Having the cambelt/water pump done next week, I will ask about a code read as I don't know anyone with a Vagcom.

If the issue does not develop past that which is evident now I shall not be too concerned, I just wondered whether this was a common issue

Cheers
D

[passat 130 tdi]

mine does this at 1800 rpm constantly , also misses a heart beat at 70mph when backing off a bit. changed all filters , 2 bottles of forte and its still there.

[djmx5]

Passat130tdi................."misses a heart beat".....thats a really good way to describe it, however mine only does it when pressing gas pedal not coming off it. Can't say I attributed it to any particular road speed but didn't think to note engine speed.

Did you ever get anything on a fault code read for this issue?

D

[PeteK]

Mine does this very occasionally (about once every month I would say), strangely enough it just did it today accelerating onto the motorway. I lifted off momentarily and reapplied the throttle gentle and felt a slight hiccup. It has done this since I bought it with 96k miles 2 years ago and has not got any worse now i've done 150k. I've always thought it was something to do with the EGR valve and because it happens so infrequently I just ignore it. I had it remapped a year ago to 170bhp and it still does the same! I have VAG-COM and it never logs a fault code.

[Clinterous]

Possible early sign that the injector loom, positioned on top of the cyclinder head under the rocker cover, is starting to fail.

I had the hiccup sympton occur to me 3 or 4 times over several months, I interpreted it was a misfire. One day whilst on the motorway, the loom totally failed resulting in loss of power and bad misfiring, enough for me to have to pull over.

On a 1.9 pd engine the loom failure is relatively common and straight forward to replace. However, probably worth getting a diagnostic check done initially to see if anything else comes up.

[stonedagain]

Mine was the same until I blanked off the vac pipe to the egr valve. Maybe the valve was a bit slow to close.

[djmx5]

I'm now wondering if this is a feature of the 1.9 tdi engine as we also have a 2007 fabia with a 1.9 tdi that also does the same on feathering the throttle I found out today. The fabia only has 18k miles so I doubt the possibility of two cars developing the same fault. Both were bought in february this year.

Thanks to allwho replied

D

[passat 130 tdi]

i blanked egr off - no difference , im now thinking its this drive by wire sensor on the pedal . oh and mines got 106000 on the clock .

may get some wd40 and spray the injector loom as a last resort . i now know when its gonna happen so i try to avoid that particular rev range as much as possible.