audi won't idle

my 89 audi 100 suddenly started acting up. it will only start with starting
fluid and then it won't idle. if the rpms go below 1400 it dies.

Many possibilities:
- Bad or non-functioning cold start injector
- Bad temperature sensor for ECU to operate cold start injector.
- Problem with ISV (idle stabilization valve) or its controller
- Air plate in fuel distributor is sticking
- differential fuel pressure regulator (don't remember the correct name) (on
front of fuel distributor) is bad or has dirty contacts
- vacuum leak - very likely
- water in the gas
- dirty fuel filter
- clogged air filter
- clogged cat converter
- blown head gasket - run a compression test
- more but this is a start

Sounds like you have some real diagnostic fun times ahead of you.

kaquinn1027 wrote:

> my 89 audi 100 suddenly started acting up. it will only start with starting
> fluid and then it won't idle. if the rpms go below 1400 it dies.
>

Did you check the main fuel distributor rubber boot and make sure it is not
broken and there aren't any missing hoses off of it.
Check for other vacuum leaks too.
--
later,
dave
(One out of many daves)

"kaquinn1027" wrote in message:
> my 89 audi 100 suddenly started acting up. it will only start with
> starting
> fluid and then it won't idle. if the rpms go below 1400 it dies.

If it's got a carburator, you might check if there's an electrically
activated idle nozzle/valve. Most VAG carburator-engines used to have one -
have experienced this on several 1.8S engines of that age. The fix is
usually to re-connect the loose wire.