1985-1998 [Subscribe to Daily Digest] |
![]() | [Main 9000 Bulletin Board | BBFAQ |
Prev by Date | Next by Date | Post Followup ]
Member Login / Signup - Members see fewer ads. - Latest Member Gallery Photos
Re: Engine running rich - check engine light on Posted by Ari [Email] ![]() ![]() In Reply to: Engine running rich - check engine light on, Jay K, Tue, 30 Sep 2003 08:45:58 Members do not see ads below this line. - Help Keep This Site Online - Signup |
The O2 sensor only has control over 25% of the fuel flow. The rest is up to the AMM, but even it has only so much control.
My guess is that something other than the O2 sensor is causing you to run rich. The O2 sensor is sending out the TOO RICH! signal, and the ECU is dialing back as much fuel as the O2 circuit will allow, and it's still stuck rich.
Yes, it is possible that the AMM is bad. The ECU fault codes aren't that good, but I would expect that you might also get an AMM fault.
My guess - fuel pressure regulator. The ECU controls the amount of fuel by changing how long the injectors are open, and the amount of fuel going through the injectors is dependent on the fuel pressure. The ECU has to assume the FPR is working properly - it doesn't directly measure fuel pressure or flow.
My guess - the FPR is bad, leaking fuel into the system, or supplying too high a pressure. The FPR changes fuel flow as a function of intake pressure, but it could be stuck at "Hi".
I would check out the FPR before I went after the AMM.
posted by 192.249....
No Site Registration is Required to Post - Site Membership is optional (Member Features List), but helps to keep the site online
for all Saabers. If the site helps you, please consider helping the site by becoming a member.
![]() |
![]() |
![]() |
![]() |
![]() |