Hey guys, our 1988 IROC-Z convertible failed horrible on the Ontario Etest at idle, the hydrocarbon limit is 57, and we scored a 138... I changed the cat 2 days ago, fixed a fuel tank leak, and repaired the y-pipe leak. When looking for exhaust leaks I noticed no air was coming from that tube that goes into the old cat, could a bad AIR pump cause such a high hydrocarbon rating? Any ideas are helpful.. I also changed the PCV, and redid all the vacuum lines dealing with the EGR, and other vacuum controlled things in that same area..

I went around spraying the vacuum lines with quick start, and there was no leaks, The ignition is also all new, the Ignition module, cap, rotor, plugs, coil, blah blah blah is all new, aswell, replaced with AC Delco products. I've ran 2 tanks of fuel through, and it doesn't smoke or burn oil, any ideas are needed as we only have 10 more days left to pass etest or the car can no longer be driven in Ontario... It's the governments way of getting rid of smog blowing V8's...

 

I would check to see if the timing is at the factory spec and use seafoam on the cylinders.
Did you also read high for nox? Is the car modified? It might not be a bad idea to seek professional help.

 

I was mistaken, it failed the Hydrocarbon at the higher RPM test, 40 MPH I believe.. We seafoamed it before we even got it on the road.. And since the etest I put the timing at 6* Before TDC, Its what I was told the original setting was. I took it for a drive today, and it feels much smoother, I have a good feeling about the next test.

 

How long did you drive the car before you had it tested? The cat may not have been hot enough to reach an efficent operatoring temp.

Over the years I have had several older cars that have had a harder time passing the smog test. Here are my tips that have always worked perfectly.

1. Drive the car for at least 1 hour before the test. A good highway cruise and not a minute less then an hour. You need to get that cat really nice and hot. The hotter it is the more efficent it will function. The longer you drive the car the better!

2. Run a high octane premium fuel before the test. Then tend to have alot more detergents in them and do actually burn cleaner.

3. Change the oil right before the test and run a 10w40 weight oil. Your car even if it does not smoke still has worn valve seals and pistion rings over the years and a little of that wear will show. The clean 10w40 will help with any containments showing up in the test.

4. Add a bottle of Guarntee to Pass or a bottle of "Heet" to the gas tank before the drive.

http://www.autobarn.net/ch05063.html

http://www.goldeagle.com/brands/heet/default.aspx

Try my tips and you will pass. I have done this on so many old cars that were having a hard time passing I have lost count.

 

We drove it in the city for about 30 minutes or so, but we sat in the parking lot waiting for a while to get the car in... I think next time we'll drive it on the expressway for a while.. I still have to braze the Y-pipe joints, they're leaking like hell..