Emissions Problem - Help!

[AZ914]

Hello all,

Down here in sunny Arizona, we are subject to the torture that is emmisions testing. Well, my 914 had been in storage for a number of years. I've got her running again and put maybe 10 miles on it but ran into a problem during emissions testing.

I passed the CARBON MONOXIDE test with flying colors. However, the car is also tested for HYDROCARBONS (HC) in PPM. The state allows a PRECOND STANDARD of 120, I pass that just fine. However, my INITIAL IDLE and FINAL IDLE readings topped out at a whopping 645 and 710 respectively, the state allows a 250 PPM IDLE STANDARD. So, no problem when the car is running on the rollers at 25-30, only at idle time. I thought that maybe there was a problem with the catalytic converter but that fails to explain why I only failed at idle. Also, I have the mixture leaned out to where my idle is bouncing between maybe 300-800 RPM when warm.

Anyone run into this problem before? Any thoughts would be greatly appreciated! FYI..I'm running a 75 2.0 with CAT, etc.

[azkiwi]

I'm running a 1.7 with d-jet and am also subjected to this annual sniff test here in Mesa AZ. Last year I ran into the same problem of high HCs only at idle. I failed the first time and spoke to one of the techs on duty. He told me that if the idle is too low that could contribute to the HC and that to also check for vacuum leaks etc (it sounded rehearsed, like he'd said it 20 times already that day). I spent the next week searching this BBS and the Brad Anders D-jet site for ideas and tinkering on the car. I checked the idle, replaced some vacuum hoses that were suspect, checked the plug gaps, valve clearance, timing and dwell, and ran the car on a one hour drive before going straight to the testing facility...it failed again with the same results. The knob on the ECU was set exactly as it was the year before so I decided to lean it out three more clicks and reset the idle speed at the throttle body. Took it back and it passed...third times a charm. Even though it may be hunting as you describe (mine was on the first two tests) you may still need to run it a little leaner.
After passing, I pulled into the parking lot and turned the ECU knob back up and readjusted the idle (after kicking myself for missing the obvious).

Hope this helps and good luck

[pbanders]

Lean it out as much as you can, make sure it's totally warmed up when you get there. As a last resort, try increasing the valve clearance from the stock 0.006/0.008 settings to 0.010/0.012 - especially true if you have a WebCam 73 in the motor.

Pretty sure the cat's on 75-76 cars are two-way at best, and may be one-way (CO only).

[pbanders]

BTW, AZKIWI, what you described is exactly how I passed the test two years ago.

[AZ914]

AZKIWI and Brad, thanks for the info.

AZKIWI:
You indicated that your idle was hunting on the first two 'failing' tests. Once you leaned it out by 3 clicks, did you have to adjust the idle UP to keep it running? (just enough to keep it from hunting?)

Thanks again..

[azkiwi]

Hi Jason,

Yes I did have to adjust the idle up once I leaned it out again...it was adjusted as far as it could (almost).

take care

Alex

[azkiwi]

Since moving to Arizona from So Cal in 1999...the only thing I miss from the move is that I would have the option of putting in one of Jake Raby's 2270 engines since the car was exempt from the smog test back there. I love the car but wish I could beat my wife off the line in her Honda Odyssey...maybe one day she'll come out and find her 3.5 V6 engine in the 914 then I could put all those "cool" powered by Honda graphics on my car...

[SteveStromberg]

Yeah I would of put a cam I your motor when I built but we didnt have that optionIf it was to pass smog check.Steve

[azkiwi]

Hey Steve,
Motor is running great...the situation I mentioned above was with the tired engine...no problems with the fresh one you built.

I don't know if I told you this but after you and I loaded it into the back of the minivan and left...my wife asked me if I felt as though I had paid enough for the engine...almost with a "do you really feel good about yourself" look. I guess it was her way of telling me that she approved of the purchase...always a tough thing to get the SAF (spouse approval factor) on big purchases. I reserved my own judgement until the engine was fired up for the first time and that didn't happen for another 8 months and after a quick trip to NZ. I tell you...I was wishing I had the teener on that trip...then I probably would have hit a cow or something while travelling down to Raglan.

Take care and happy holidays

Alex