Hi all,
being out of South Africa, I'm not very smog savvy.

Rebuilt an '89 RS for my son, but it failed smog because it was running too rich. Also backfires when cold (limited).

Timing is in

Replaced:

O2 sensor
Injectors

and did tune up.

I would really appreciate any suggestions on what to look for go forward.

Allan.

 

What did you change in the tuneup?

 

Tks for the reply.

plugs, air/oil filter, rotor, dist cap

 

<a href="https://www.thirdgen.org/techbb2/showthread.php?s=&threadid=162251">Click here and read this message</a> and cross off anything you've done already, see what's left to do.

Did the mechanic give you any numbers? (High HC or CO or NOx) Or did he just say the car was running rich?

They say one misfiring cylinder can put out as much emissions as 3 or 4 cars...

 

The HC & CO were high.

Still need to replace the Plug Wires & PVC valve (what's this ?).

Also will do the fuel treatments as the injectors were not brand new.

 

if you don't pass after that stuff get the compression checked, that could give you a clue...here's an example of something that won't pass
145
143
145
142
83
12

thats my car...the HC numbers were like off the charts

maybe you'll need to run that "guaranteed to pass" stuff through to make it pass

 

Here's what also helps.
Change oil-REALLY!
DO THE PLUG WIRES & SUCH
Ya MAY NOT be burning ALL fuel in cylinders
AND
a GREAT spark will cure that problem!
Next, once warmed up, head to freeway with a tank full of premium fuel and (I LIKE & WORKS QUITE WELL) Liquid Gumout for fuel injection.
Get the car to run like a champ.
Go for smog test.
NEVER SMOG TEST A COLD CAR.
And if ya need wait, shut off the car, all the time.
When ya start it, give it a solid gas pedal woosh!

THIS WILL HELP.

Yet if the compressison reads like above, go to Plan "B"!

Best thoughts as I go to smog my Firebird in a short time from now. I do not expect a problem at all. For smog testing, I change back to the original air cleaner set up which I saved for this smog test purpose

 

Thanks to all that posted the good advice - will let you know what happens.

A.