80 TDi Couple of probs/questions

**Marc97** · 17-11-2006,04:17 AM

Firstly, I'm a new member so hi all.
I bought a '95 (M) 80 TDi about a month ago, my first Audi TDi although I have owned a Coupe before.

Anyways, down to the nitty gritty, When I set off, as I press the clutch to change to second, the revs will go up and hold at about about 3500 - 4000 rpm for a second before they start to drop back down and when I've changed to second gear and put my foot back on the throttle, it either does nothing or is very un-responsive as if I'm barely pressing it, again, only for a couple of seconds, after which the car drives normally. This is an intermittent fault which only happens a couple of times a day but I would like to get to the bottom of it.

I'm also interested in fitting a 'tuning box' but have no idea whether my car is PD or non PD?????? Were PD pumps only fitted after a certain year??? Can anybody give me any idea what I need to look for to answer my question?

Car has 162000 miles on it, no idea when it was last serviced but seems to have plenty of power and is responsive (compared to the Astra TD it replaced!!!!), so I'm at a loss where to even think to start looking for a fault.

Cheers,

Marc.

**pcar964** · 21-11-2006,04:04 PM

Marc,

Did you find a solution to this problem? I have a very similar problem on my M Reg 80 1.9TDi Avant.

Another issue is that there is next to no power at low revs in first gear, then when the revs pickup the turbo cuts in causing wheel spin. Makes hill starts and pulling out of T junctions very difficult.

Any ideas anyone?

Thanks,

Peter

**Marc97** · 21-11-2006,05:18 PM

Hi, no I haven't managed to get to the bottom of this one.
I too sometimes have trouble pulling away but I think thats down to the same problem where the car just doesn't seem to respond at all to the throttle.
If I get it sorted, I'll be sure to post the solution.

**pcar964** · 21-11-2006,05:28 PM

Hi Marc,

That describes it really well. Pressing pedal results in nothing, then a sudden surge as turbo kicks in. Also experience it in other gears if I come of the throttle or coast, then apply throttle again - no power.

Lack of power when pulling away in first sometimes means steering is very heavy as if the power steering belt had snapped.

I hope we can find the cause and the solution.

Peter

**Marc97** · 21-11-2006,05:37 PM

Just a quick question.
When the car surges, does taking your foot off the accelerator actually do anything? I mean, does the car stop revving or does it carry on as if it was possessed?
The non responsive throttle pedal is usually preceded by unneccessarily high revs between gear changes.
I think I'll get an exorcist to have a look at mine lol.

**pcar964** · 21-11-2006,06:02 PM

I experience the non-responsive throttle pedal almost always in first gear when trying to pull away. Engine gives very little power and if I give it progressively more throttle, nothing happens until all of a sudden car takes off rapidly often spinning the wheels. Makes driving in slow moving traffic very difficult and almost dangerous.

As I said, happens in other gears too after coasting with clutch disengaged or lifting foot off throttle pedal to slow down.

The surge in revs is when changing gear, so foot is already off the throttle pedal, this is much more intermittent than the loss of power.

I have not experienced any connection between the surge in revs when changing gear being preceded by lack of power.

**Marc97** · 21-11-2006,06:08 PM

Originally Posted by pcar964

I have not experienced any connection between the surge in revs when changing gear being preceded by lack of power.

Its the other way round for me and seems more related ie:
1st, surge in revs between changes
2nd, lack of power after change when releasing the clutch and getting back on the throttle.

As I said, luckily, it doesn't happen too often BUT, I can reprodude the problem on demand.

Push the throttle to the floor with 3 quick blips, revs rise to around 4000 and hold there for a couple of seconds (my foot is off the throttle at this point) then press throttle when it returns to idle. Result: no response.

**adamss24** · 21-11-2006,07:30 PM

Originally Posted by pcar964

I experience the non-responsive throttle pedal almost always in first gear when trying to pull away. Engine gives very little power and if I give it progressively more throttle, nothing happens until all of a sudden car takes off rapidly often spinning the wheels. Makes driving in slow moving traffic very difficult and almost dangerous.

As I said, happens in other gears too after coasting with clutch disengaged or lifting foot off throttle pedal to slow down.

The surge in revs is when changing gear, so foot is already off the throttle pedal, this is much more intermittent than the loss of power.

I have not experienced any connection between the surge in revs when changing gear being preceded by lack of power.

I take it you never drove a diesel prior to this car, innit ? Thats common with TDI due to their relative high torque compared with a similar petrol engine. You will soon adjust your driving style as when releasing the clutch it needs a light blip and you are away, no need to accelerate and then quickly accelerating trough gears. Because of the torque, you will find its not necessary to downshift so often as with a petrol car ! Also you will see that its easyer to drive a manual diesel in slow moving traffic as the engine will pull in second or third at tick-over and returning better Mpg. I have trouble adjusting my driving style when i drive missus polo 1.4, i mean its either underreved or overreved and it takes about 5 min to adjust my usual heavy foot to the light featherweight acceleration of the polo. I often stall the polo when i drive off from a stand still but i never stall my diesel. When i need it to go slow- i use i light foot and when i wanna go fast i just boot- it.

**adamss24** · 21-11-2006,07:38 PM

Originally Posted by Marc97

Its the other way round for me and seems more related ie:
1st, surge in revs between changes
2nd, lack of power after change when releasing the clutch and getting back on the throttle.

As I said, luckily, it doesn't happen too often BUT, I can reprodude the problem on demand.

Push the throttle to the floor with 3 quick blips, revs rise to around 4000 and hold there for a couple of seconds (my foot is off the throttle at this point) then press throttle when it returns to idle. Result: no response.

You, my friend, experience what its known as Turbo Lag and in your case could be accentuated by a sticky/slow raecting/sooted-up VNT mechanism, that is common with high milleage cars driven in heavy traffic or in coffin-dodger style...!

**Marc97** · 21-11-2006,08:30 PM

Thick mode again. Whats a VNT?

Thanks for the reply, I'll try and clean out the 'VNT' asap and report back.

PS, I have owned TD cars for quite a few years now and I am used to plenty of lag at low revs although this is my first TDi and my first electronic throttle car. The feel of the throttle is eerie in comparison to my other cars.