View Single Post
  #4  
Old July 22nd 05, 06:21 PM
Tony
external usenet poster
 
Posts: n/a
Default



Christoph Bollig wrote:
> Hi everyone,
>
> My 1989 Audi 100 is not running very well and during idle id doesn't
> sound too smooth. Especially at lower revs, the power is done and it's
> not smooth either. It feels as if it is running only on four cylinders
> (5 cyl engine) and sometimes it gets even worse as if only three are
> left working. Some time ago, I pulled out HV wires during idle and it
> is definitely cyl no 2 which is not working. However, the spark is
> there and I exchanged the distributor cap and all HV wires with
> another car. The problem is still there, so I concluded that it's not
> the ignition.


How does the plug look? Similar to the others?
It could be that the balance of the I5 engine masks the effect of pulling plug
wire on #2.

>
> The problem was there some time ago, then went away suddenly while
> accelerating and came back a few weeks later. Unfortunately, it
> decided to stay with me now.


Before throwing money at ignition parts you may want to consider other causes. I
would be suspicious of engine vacuum.

Test while idling:
Pull oil dip stick up. Engine should begin running very rough.

Replace dip stick.

Remove oil fill cap from valve cover. Engine should stall (quit)

If these do not perform this way you need to isolate and fix the vacuum leak
before other things. The crank case breather tube is a chronic problem on the I5s.

>
> I am a bit stuck now. I assume it has to do with the fuel injection,
> but I don't know where to start. Is there any typical problem I can
> check?
>
> Thanks a lot for any advice,
>
> Christoph
>

Ads