Audi 80 tdi juddering bucking jerking

[avanttdi]

me too. juddering in any gear at light throttle openings between 1000 to 2000 rpm then it clears.

if you put your foot down it pulls out of it

hunting at idle too

my turbo hose split, and was replaced by the previous owner. the fault has been there ever since. the two problems are related im convinced of it

[Obsidian]

ditto the above two replies, i'm looking for a sensor too, though i suspect there maybe configuration differences between model variants.

I've noticed several fabric type hoses or hose connections, one in particular on the inter-cooler sensor tapping (the nipple into the air duct), these seem old and brittle and possibly subject to air/pressure leakage. Maybe worth replacing them one by one until either they're all changed or problem gone.

Thnx for post regarding inter-cooler removal and cleaning, mine's located between the front drivers side wheel and the front bumper. It's a tad awkward to remove, the air pipes are large and awkwardly situated and the whole proceedure requires the removal of the drivers front wheel and inner wheel-arch, along with most of the flexible hoses off the turbo unit.

Did someone say they had removed the turbo unit complete with the exhaust manifold? can u actually get to all the bolts for the exhaust manifold with the turbo in place? i can't seem to too see most of the bolts in that area for the ruddy thing!

[hawkeye1975]

Hi Alan,

I dont have rough tick over, but i too have jerking at low rpm's and my turbo hose split and had to be replaced.

I also have the random cutting out syndrome, but i don't think the jerking and the cutting out are related. I've got air bubbles in my inlet pipe to the fuel pump.

1994 1.9 TDi, do i have a MAF ?? i can'nt find anything thing on this car ??

[allan_audi]

Hi Alan,

I dont have rough tick over, but i too have jerking at low rpm's and my turbo hose split and had to be replaced.

I also have the random cutting out syndrome, but i don't think the jerking and the cutting out are related. I've got air bubbles in my inlet pipe to the fuel pump.

1994 1.9 TDi, do i have a MAF ?? i can'nt find anything thing on this car ??

me too. juddering in any gear at light throttle openings between 1000 to 2000 rpm then it clears.

if you put your foot down it pulls out of it

hunting at idle too

my turbo hose split, and was replaced by the previous owner. the fault has been there ever since. the two problems are related im convinced of it

Strange! What does the split turbo hose have to do with the VSS signal, can't see a connection. I wonder if the turbo overboosts, but can't see how it would damage anything except the turbo, cause there's no pressure build up. I know when I had my car the turbo hose was loose, no power etc, just tightened the hose clip on the turbo.

I've replaced all hoses (the small cloth covered hoses for turbo wastegate control), I no longer have EGR valve so removed hoses for those. Thats made no difference at all.

As I've said before Hunting at idle is fixed with VAGCOM.

Yeah 1994 Audi TDI has MAF, its in the pipe between the Air filter and Turbo inlet, but don't just replace, I checked mine with VAGCOM, seems ok.

As for the bubbles, I've replaced all fuel lines, the solid feed and return, all rubber hoses, even on the tank, and in engine bay, and I still get air bubbles. I'm convinced this is either Fuel Injection Relay or Fuel pump itself.

[hawkeye1975]

Thanks Allan,

I wondered whether the "cutting out" i get, completeley randomly, was the air bubbles ??

[allan_audi]

Thanks Allan,

I wondered whether the "cutting out" i get, completeley randomly, was the air bubbles ??

Yeah thats what I was implying, I've never been able to stop the air bubbles, its got to affect the Injection pump, having mixed fuel/air rather than pure fuel. Have you noticed if it happens more with a low fuel tank?? I haven't noticed the problem for a few days but its done it couple times today, and the tank is low, this would indicate fuel pump. I think the first thing to try is new injection relay, not sure how much a new fuel pump is.

I've tried changing the boost control valve (N75 Valve in VW speak) and hoses with no difference at all.

[midskev]

ditto the above two replies, i'm looking for a sensor too, though i suspect there maybe configuration differences between model variants.

I've noticed several fabric type hoses or hose connections, one in particular on the inter-cooler sensor tapping (the nipple into the air duct), these seem old and brittle and possibly subject to air/pressure leakage. Maybe worth replacing them one by one until either they're all changed or problem gone.

Thnx for post regarding inter-cooler removal and cleaning, mine's located between the front drivers side wheel and the front bumper. It's a tad awkward to remove, the air pipes are large and awkwardly situated and the whole proceedure requires the removal of the drivers front wheel and inner wheel-arch, along with most of the flexible hoses off the turbo unit.

Did someone say they had removed the turbo unit complete with the exhaust manifold? can u actually get to all the bolts for the exhaust manifold with the turbo in place? i can't seem to too see most of the bolts in that area for the ruddy thing!

yeah i took the turbo compleat with the exhaust manifold took all the pipes off ect removed the air filter box egr valve n pipework i found it wasnt to hard to get at then i took inlet manifold off and cleand that too was worth doing took me longer to clean it out that take it off lolol

[hawkeye1975]

Thanks Allan,

Before i start panicing, i'm gona check that the fuel filter and bleed screw arn't letting air in.

Update on the judder and cutting out. Doesn't seem to do it when it's cold.
The cutting out seems to get worse for a few seconds after "spanking" round a corner?? wonder if this means anything to you guys??

[allan_audi]

Thanks Allan,

Before i start panicing, i'm gona check that the fuel filter and bleed screw arn't letting air in.

Update on the judder and cutting out. Doesn't seem to do it when it's cold.
The cutting out seems to get worse for a few seconds after "spanking" round a corner?? wonder if this means anything to you guys??

I've already replaced the entire fuel filter and housing, still get air bubbles. I don't get the problem cold either, but what you're seeing could be fuel pump, its the only thing I haven't changed, with exception of fuel pump relay.

PS. Just to be clear!! I am talking of the lift pump in the fuel tank and not the high pressure fuel pump on the engine. The High pressure pump cannot draw the fuel so there's a lift pump fitted in the fuel tank.

[hawkeye1975]

Aaahhh, i didn't know that Allan !! thought it was just the main fuel pump, will stop sweating so much now !!!!

So, you say there is a lift pump in tank?? will check this out.

Thanks again