I traded my old Formula for a 91 Firebird and it is running extremley rich at idle, when I start it up I can smell the gas alot, so I checked the plugs and of course they were black and wet with gas. So I checked the codes today and nothing not one code. When I test drove the car the Check Engine light came on for a few minutes then went off and hasnt been on since.

Whenever its idling and I gun it it will kinda sputter then kick back in.

The car has new plugs, wires, cap, rotor. Also the car has a punched out cat.

Any ideas on this? Could it be the o2 Sensor?

 

Since the SES light came on, you should have a stored code now. Pull the code and see what it is.

It does sound like you're going into open loop at an idle, which is usually caused by a bad O2, so that's a good place to start.

 

Leaky injector??? Mine acted very similar last winter, it ran very rich as I could smell fuel while waiting at stop lights. It would throw an occasional EGR code which would sometimes go away on its own. I also have a fully operational emissions system. While all this was going on, I had the car on a dyno where it only put 102hp to the rear wheels. I have since put in some new (rebuilt) injectors, 2 were slightly leaky, and so far it's running really good. No more fuel smell and no more codes. I dynoed it on a different machine since the new injectors and ran comparable to another V6 which put down over 120hp at the first dyno with me last winter.

 

another reason youre going to smell gas is because the cat is punched out. its there to burn any left over hydrocarbons. probably a good idea to get it replaced, most of the new ones are very close to not having one at all anyway. they dont really restrict flow.

 

Yea I kinda thought of the cat being a factor also. Since the SES light came on last time I unhooked the battery to install a stereo so I thinked that wiped the code. The car only runs like that when its cold after I drove it down the street I couldnt smell anything and the car was idling lower and wouldnt cut out when gunned.

When its cold the car idles around 1100-1300RPM sounds a little high to me. When it warmed up it was down to like 800 RPM.

Also would an o2 sensor work off of a Grand National V6? because there is one sitting in auto class with a new o2 on it and I could take it without anyone knowing.

 

theres a lot of things that could cause this problem without kicking the light on. OBD I vehicles arent as sensitive OBD II. and as far as the O2 sensor working, i dont know. you can call a parts store and see if they have the same part numbers or call a dealer. my guess is it would be different due to the GNs running boost, and ours arent. i also think those have a different ECM. if youre suspecting it, theyre only $20 to pop one in. but even if it is bad, your converter would take care of the rich smell. id put an O2 and a converter on, if you do it yourself, $100.

 

Well, the parts numbers where the same for the o2's so I put it on but havent got around to changing my plugs yet so I havent ran it, the old 02 sensor was covered in black soot (thick stuff).

If I have a stuck injector would all cylinders be running rich or just one? because I got all but one plug out and they were all black and reeked of gasoline so does that mean I probably dont have a stuck injector?

 

could have an injector stuck closed and that is causing the ECU to richen up all the cylenders till the 1 O2 shows right.

 

90Tsi ,you should update your classified ad or reply to it at least

 

Ok well I started it up today for the first time since plug change and o2 change and its still running rich. After idling for like 5mins the car didnt want to start again and there is still black smoke coming out of the exhaust! I can already tell it fouled my NGK's.

So about this injector thing how do I tell if I have one stuck open or closed or whatever.