Running Rich???

[vettin1]

I just had the car inpected and all the other levels were fine except for the CO (carbon monoxide) levels were almost at tolerence. The tolerence level is 15.0 here in NYC and the car came back with a level of 13.8, thank god it passed!!! Could this be from the engine running rich??? I also know that the CAT is the original on the car since I had it, thats about 5-6 years and it looks real old like it is probably way older than that. Could that also contribute to this??? The exhaust I am upgrading in a few weeks and I am also gonna buy a new CAT. Will this solve or help the problem???

Have a happy 4th of July weekend everyone!!!

 

[Edmond]

Either a failing cat or running rich will increase the carbon monoxide levels. Do you still have the precats on your car?

Any codes come up?

 

[vettin1]

As far as I know an 85 has no pre-cats, I know I don't have them. The computer also throws no codes!

 

[oldace84]

Pull the spark plugs.

tony

 

[vettin1]

I was thinking of doing that. Someone also suggested to me that I should try the fuel injection cleaner. I will try both and report results.

 

[Edmond]

I was thinking of doing that. Someone also suggested to me that I should try the fuel injection cleaner. I will try both and report results.

Are those Bosch injectors in there? If they are; I was told that you should not use any fuel injector cleaners because they can wear the o-rings on the injectors.

Also check the PCV located on the drivers side rocker arm cover. That little valve can clog up. It's only a $3-4 part and it makes the ride smoother.

Check the EGR valve to see if it's clean.

 

[vettin1]

PCV and entire EGR system changed approx 2 weeks ago. The tech that did the inspection said that the NOx results were so low becuase of the new EGR parts (I discussed this with him before I left the shop today), the NOx levels are controlled by the EGR system according to him. The results were as follows:

Emissions HC CO NOx
Test Limits 0.80 15.0 2.00

Test Results 0.38 13.5 0.53

The tech said that he smelled it before he ran the test and was surprised that it passed but as you can see it JUST passed on the CO levels, that's what has me concerned.

The things that were just changed and cleaned in the last month are:
TPS Sensor
EGR Solenoid, Valve and sensor
Some vaccum lines that i was not satisfied with
PCV valve
Air filter cleaned and lubricated (K&N)
Throttle body cleaned around butterflies

 

[vettin1]

sorry, yes they are the bosch injectors, i guess injector cleaner is out of the picture, thanx for the heads up!

 

[jiangtao]

My damn{no,I love it}'86 has always ran rich!!I have just learned to live with it.Here in good 'ole Bama we don't have emissions.Yet!These emissions cars are a major PITA sometimes!

 

[vettin1]

they are a PITA!!! The car has always came through the emmissions testing at about 8.0 this is why I'm thinking there is something wrong or that has to be tweaked.

 

[Edmond]

How old is the oxygen sensor? A weak oxygen sensor can give a not too accurate air/fuel mixture reading.

The instant improvement in throttle response with a new O2 sensor is awesome!

 

[WhalePirot]

A new CAT can clean up a LOT, but you want to NOT need it, by fixing any problems. You can get a decent idea through smell and the tailpipe color.

NoX is cleaned up by lowering combustion chamber temperatures, by injecting exhaust gas into them during certain lean conditions.

CO is the unburned hydrocarbon measurement. CO2, has more oxygen in it than CO, so YES, it seems it is running rich.

The plugs can tell a LOT. By making a numbered holder, you can see if all are the same color/condition, or isolate a problem cylinder.

The problem can be electrical or not. Proper plugs, good wires, cap and coil are all needed to get a good flame started. Proper sensor input to the ECM is needed to get proper fuel mixtures. O2 sensors have a life of 30-50K miles, I believe. They can be fouled more quickly with improper mixtures passing by.

When I get SMOG tested, I always use the best fuel and ensure that the car (esp. the CAT) is well warmed up. Ensure it is getting the AIR to process the exhaust, too. Good detergent fuels should clean and keep clean, those injectors. A GM fuels engineer did a great piece on this forum, quite a while ago about that.

I HAVE retested with a great improvement by 'rebooting' the ECM. Unplug the power to it for at least 10 seconds, just like clearing codes; then retest. Sometimes, they just learn bad stuff.

'84 and '85 used the same exhaust, with one CAT connected with 4-bolt flanges to the front Y-pipe and CAT-back system.