when i ran my maverick through i just got it really hot and put in a few bottles of HEET gas antifreez. people told me to use the lowest grade gas since it would burn off quicker, which i did (before E10 started) My emissions levels were way below the standard. funny thing was the previous owner removed the pollution pump and i didnt know it even had one in the first place, either way it passed without it. took the comet through last month with none of the necessary precautions, it was probably cold as well and it failed the first time. brought it back later that day HOT with some HEET in the tank and it passed. the comet still had a functional pump too. those things probably do more harm than good anyway. I hate the dmv emission tests. some how i got to figure out how to get some tags for my ch3vy stroker powered '85 olds lol. cant go antique/historic because it needs to be in stock un-modified condition, maybe i can pass it off as a 305 lol
Hey folks, hope it's alright that I'm reviving this old thread... I'm hoping to get my '77 Maverick 250 i6 auto through emissions here in Oregon. There are some additional obvious things that I can do (replace distributor cap and rotor, mess with the carb, oil change), but I wanted to get your ideas on this case before I go to town... mainly because something unexpected happened and I'm a little baffled. So the limits in OR are as follows: 220 HC (guessing that's in PPM) CO less than or equal to 1% of exhaust CO+CO2 6 (no idea what that means). On my first test, here's how I scored: First Idle: 184 HC (pass), 3.7% CO (fail), 12.5% CO2 Second Idle: 237 HC (fail), 3.6% CO (fail), 12.6% CO2 Smoke test: pass. I replaced the air filter (which was pretty dirty) and threw in a can of seafoam, checked the tire pressure (a little over-inflated) and made sure the gas cap was on tight. The oil still has amber in it - not black enough to warrant an oil change I don't think. Five days later (today), I took the car on the freeway for around 30 miles or so and then pulled into the DEQ testing station. My results were: First Idle: 263 HC (fail), 5.1% CO (fail), 11.3% CO2 Second Idle: 257 HC (fail), 4.1% CO (fail), 12.1% CO2 Smoke test: pass. How did I score worse on this second test? Is it possible that the seafoam is cleaning some engine filth, causing it to exit out of the exhaust, leading to higher HC and CO readings? It's hotter than it was five days ago (I think), but it isn't that much hotter. Wondering if that could be having an effect? Is there anything in particular I should take a look at first? I know that the carb likely needs to be adjusted - it's a new one though and I'm reluctant to touch it given that it was tuned by the person who installed it, an older guy who got his start in the 70s and seems to know what he's doing. Maybe there's something obvious I'm missing. Curious to know what you think. Thanks!
I've seen Seafoam help with emissions issues but overall, not a fan of miracles in a can. If plugs are older, should be replaced. Carb idle mixture is generally one of first adjustments that needs to be checked.
It used to be easy. Not now, to many coming into the US. You know you can beat a ticket if you live in the US. Take it to trial.
Hi folks, thanks for your responses. Over the weekend, I replaced the spark plugs (they looked okay tbh), the distributor cap and rotor (one of the few standard tuneup parts I haven't replaced since buying the car 4 years ago), sprayed some carb cleaner into the carb and adjusted the idle mixture screw just past the point where the engine starts sounding rough. Results from my third test were as follows: First Idle: 475 HC (fail), 1.4% CO (fail), 12.7% CO2 Second Idle: 824 HC (fail), 1.4% CO (fail), 12.0% CO2 Smoke test: pass. CO emissions went down quite a bit but are still not below acceptable levels. Hydrocarbon emissions went up by a lot. I bet tuning the carb correctly will fix some of the trouble (looks like a lean fuel mixture was the culprit behind the huge HC increase), but not all of it, so I'm wondering what else I might be able to do to get my Mav to pass.
Use a vacuum gauge, adj mixture for highest & smoothest idle. Rough idle mostly caused by misfires. Lots of good info... https://www.motortrend.com/how-to/45638/
