1989 running rich
Thread Starter
4th Gear
Joined: Jul 2010
Posts: 4
Likes: 0
1989 running rich
hi i have a 1989 corvette, i have changed the o2 sensor and the temp sensor and mass air flow. have put it on a scanner and nothing came up. drove car and only code i get is 45 and nothing else. does anyone have any suggestions not sure where to look now. any help would be nice thanks
Pro
Joined: Mar 1999
Posts: 678
Likes: 0
From: Oslo, Norway
Hi Just another topic. Check for exhaust leakage in front of the O2 sensor. It might be a bad valve or hose in the manifold . If that is true there will be oxygen in the exhaust and the Eccm will compensate and enrich the fuel supply and then it goes rich.
Drifting
Joined: May 2002
Posts: 1,581
Likes: 2
From: The Motor City
Melting Slicks
Joined: Dec 2009
Posts: 2,231
Likes: 284
They have cans of maf cleaner at most parts stores, its like carb cleaner but less harsh. The reason I say clean the maf sensor is sometimes the oil in K&N type filters will coat the thin wire in a maf sensor, then the readings will be false.
Drifting
Joined: May 2002
Posts: 1,581
Likes: 2
From: The Motor City
Forgive me, I don't mean to be starting an argument here. I've just never heard of anyone cleaning a MAF sensor, especially on TPI equipped cars.
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
It wouldn't spit a 45 with an exhaust leak which would make it lean (and the ECM would then add too much fuel). With a 45, the ECM is trying to lean it out by reducing pulse width, but it isn't working. Do check fuel pressure to make sure there isn't a leaking injector and if doesn't hold, pull plugs until you find one that's soaked with fuel to locate the bad injector. If pressure is fine, clamp off the emissions evaporator (canister) hose to the throttle body and see if it swings lean. If so, check the Canister for raw gas and the check valve. If high mileage, measure valve lift and check for a broken exhuast valve spring.
