76 280 wont pass cal smog too rich!

[dastuffuwant]

1st ive had the car for about a month and i noticed if i remove the oil cap she dies. not sure if thats normal. next i noticed the o2 sensor isn't connected to anything. which the smog guy says could be why she's rich? this is my first z and the engine runs real good and doesn't smoke or leak oil. is there a way to lean her down. please help! THANX

Edited January 26, 2010 by dastuffuwant

[Z Tyler Z]

I don't know very much about smogging a car (No testing here in Wa for anything older than 25 years).

But why are you removing the oil cap when the car is running? The car dies because your letting un-metered air into the car. Our cars have Air flow meters that meter all the air that goes into the engine, any air that's un-metered will throw ECU off and as you said your car dies. This is perfectly normal.

Also first generation Zs didn't come with a O2 sensor that started with the Zx generation. If you take a picture or describe the part your talking about I'm sure someone will know what it is.

If you search a bit I'm pretty sure this topic has come up a few times in the past and there could be some helpful advice there.

Also welcome to the forum.

[WingZr0]

Connect all the sensors and if the oil cap or dipstick is pulled it will cause a loss of vacume preasure which will kill the engine. It's normal but try not to do it. If your water tenp sensor, what you might think is a O2 sensor, is bad or not hooked up right the computer is tricked into going rich.

Edited January 26, 2010 by WingZr0

[billyjarrell]

Don't know if it helps or not but I've had 2 injected Z's run rich on me.. On my 75 the airflow meter was wasted causing an extremely rich condition and on my 76 injector number 3 was leaking into the intake causing that cylinder to be extremely rich. I've also heard of the normal things like coolant temp sensor/connector or fuel pressure regulator diaphram being wiped out causing a rich condition at idle or pulling raw fuel through the vacuum line. Also make sure the cold start injector isn't supplying fuel all the time.

[dastuffuwant]

Ok guys thanx for the help. i'll try the to check the things mentioned. thanx

[dastuffuwant]

hi, i cannot find the EGR. is it possible for the car to run without it. i will post pics later but i searched everywhere (i think) and its not where its supposed to be.

[deadflo]

I'm not sure if a 1976 would have EGR or not, if it was not sold in California??

If all your sensors are hooked up and OK, it's likely the air flow meter is wearing a bit and causing it to run slightly rich. The Field service manual will tell you how to check all your sensor readings at the connector to the brain and take Resistance readings to see if they are operating properly. You can also use the ohm meter to see if the air flow meter is giving consistant readings as the flap that measures the air opens.

[Z Tyler Z]

I'm not sure if a 1976 would have EGR or not, if it was not sold in California??

Your correct, 1975 and 1976 models didn't come with EGR, unless they were originally sold in California.

dastuffuwant, did you ever reconnect that sensor that wasn't plugged in?

[dastuffuwant]

no, i could not find anyplace to connect it to. heres sum pics

[dastuffuwant]

here's the engine pics

[dastuffuwant]

there is a pic of the sensor in pic #2 and 3 thanx

Edited February 1, 2010 by dastuffuwant

[sblake01]

That is an O2 sensor but you're engine appears to be a 79 or later engine which would have an O2 sensor if the attending exhaust manifold was used. Problem is that there is no provision for an O2 sensor on the 78 and eariler models, nothing to connect it to.