Volvo 740 GLT 89/90 B234F

Hope someone can help.
My 745 GLT (16V) missed the Gas test cause of the CO are 1% (max 0,5%) , the
ECU do not display any faults (1-1-1) the lambasond (o2 sensor) has been
replaced WO result.
Any ideas are welcome. All other have just given the advice try the AMM or
the cat now you have exchanged the O2-Sensor...but that kind of burn and
crash are expensive....why I need someone who have had the same problem.

Keep driving VOLVO

RiBe

 

On my 740 Turbo that problem was caused by the cat, how many miles are on
yours?

 

Oh yeah, my friend's 740 8 valve failed also with the same problem because
one of the plastic caps had broken off the tip of one of the fuel injectors.

 

I don't claim to be an expert but it seems like your car runs too rich.
I think that your AMM has an adjustment to some degree, which is
measured at the removeable plug in your cat.
I did have a similar situation. My 87 740 was borderline failure in
Calif but the NO was just over, making me fail. I used a laser
thermometer and my 740 had a very hot cat output, meaning that it was
working to burn off unburnt fuel. I replaced a few old vacuum hoses at
the motor, and cleaned out the small clogged pipe leading to the
crankcase vent trap. I put in a fresh set of platinum plugs, changed the
oil and filter, and put in a new O2 sensor. It passed .
I think your car needs to be checked for all the common things that
would make it run rich, like CO adjustment, polluted motor oil, bad
injectors, incorrect fuel pressure, dirty air filter, etc.
Richard

 

Change the oil and filter. Makes a world of difference in pollution tests.
If that doesn't work, find someone who knows how to set up the throttle body
properly and adjust the air mass meter. That means someone with factory
training. With over 500 hours traing on Volvo in Atlanta and Orlando and 800
on BMW I wouldn't steer you wrong.
I usually check this news group daily, so let me know how you make out, or
e-mail me. Good luck.