john walkers workshop

usually i can figure these things out, but this one has me going.
when hot, you can open the throttle and nothing happens. won't rev up. it also has a rough idle.
the bosch hammer says "closed loop lean not present". obviously running too lean. that's the only DME fault shown.
it has a new oxy sensor, head temp sensor, fuel filter, dme relay, and airflow meter.
a known good computer and fuel pump have been tried.
there are no air leaks, and the fuel pressure is good. haven't checked volume, but that should not relate.
all the electrical plugs have been checked and cleaned, and the harness at the airflow meter has been checked.
compression is fine.
here's the clincher:
if the oxy sensor is unplugged, the engine runs quite well. i could drive it all day.
any ideas???

ron mcatee

You may have a bad oxygen sensor even though it is new. Mine did the same thing and I replaced the oxygen sensor with a secon new one and that was the problem. Hopefully, you might get lucky too.

Spider911
88 Carrera

chris walrod

isnt there a way to test a O2 sensor with a VOM?
If I remember correctly, they generate a voltage (in the range of millivolts) through a chemical reaction with the exhaust.

Just my O2 cents worth... get it....O2

I know that was dumb.

Chris

john walkers workshop

it did this with the old oxy sensor too. even though it had the correct voltage readings, i replaced it because it was old. the new one has the same readings as the old one.