[urq] sudden stumbling

[spot.ontheroad at virgin.net]

Johan
Sounds like fuel starvation to me. Some quattros (although not all for some reason) had a gauze "sheath" on the outlet from the fuel tank (in the tank itself) to act as a pre-filter to stop bits of rust etc leaving the tank. Sometimes this can become clogged. It is largely surplus to requirements as there is a sediment trap and a filter to protect the system and so can be broken by pushing a rod up the outlet pipe (after having first drained the tank) I know one person who did this and restored fuel flow and cured the stumble but I would rule out all the easy options first before going to the trouble of draining the tank. Rule out electric problems and then get the fuel pressures checked. Don't try to drive "through" the stumble in case it is fuel starvation causing a lean mixture.
All the best
Keith
'87 WR