06-01-2008, 06:00 PM
Join Date: Jun 2008
Hi Everyone, I am new to this forum (Sorry for the long post)
I am in the process of buying an 87 Samurai. It runs great but doesn't pass CA smog (I am in San Diego). The owner suspects that it only has 40k miles on the engine. I tend to agree with him by the way it runs and looks under the hood.
It gets almost all the way through a smog test just to fail on 25 mph HC (163ppm) and CO (1.91%). Max values for each respectively are 126ppm and 1.45%. The 15 mph test past well within the Max limits.
The present owner installed Catalytic Converter a month ago trying to get it to pass so he could sell it. But got frustrated and gave up (he said it was costing too much).
I took it to a friend that has a test only station and he had me run a tank of gas mixed with a bottle of "Guaranteed to pass". I ran it down to fumes and then filled up with fresh gas. I ran it hard for an hour then had him run a "dianostics test" and we got the above numbers. He suggested that the first thing to change was the O2 sensor, the second thing was to install a 195* Thermostat, I did both.
He also suggested that I check the Float Level which is a little high. I'm not comfortable tearing apart a Carburator apart at this stage.
Can a high float level cause high HC and CO levels?
I put it into test mode by flipping the Cancle Swith. The manual says the "Sensor" light should blink off and on as the ECM cycles the O2 sensor off and on. It doesn't blink. I have driven it for a few hours now without the light going off even for a second.
I spent most of yesterday going through a DL'ed shop manual and testing what I was comfortable testing. The manual listed 7 things that had be working to cycle the light off and on.
1-O2 Sensor (I put the old one back in without change)
2-Defective Thermal Switch (I verified that it changed state going from cold to hot water)
3-Idle and Wide Open Throttle switches operating correcty (They seemed Okay when testing them with an ohm meter under the glove box).
4-Check all electrical connections to emission control systems (as far as I can see everything seems connected properly)
What I haven't tested/adjusted because I am not sure if have the technical ability is the following.
5-Mixture Control Solenoid Valve
6-Defective Carb and/or Idle Mixture adjustment
Should I keep working on it myself? Or take it to a local Carb shop? Or should I give it back to the owner?
PS... PetroWorks said they will work on it but they can't get me in for a month or so but they won't guarantee it to pass :-(
Thanks for the great forum!