Emissions problems .... Options

[jsteele22]

A few of my new friends in law enforcement convinced me to get my '76 2.0L registered, which means an emissions test. The PO had problems (back in '98) and the car hasn't been clean since then; that's one reason I had been putting this off.

I've already replaced points, rotor, cap, wires, and plugs. Adjusted dwell (which I feel pretty sure about) and timing (which I'm less sure about). For the timing, I used the handy template from Pelican Parts website, and put a visible mark on the impeller. But its so hard to work through that viewport that I might be off by a little either way.

Also, I ran 3 tanks of gas w/ injector cleaner (and *did* see some improvement during that time). I found that my decel valve did not work, and removed it. I had problems w/ the AAR wire shorting to ground, blowing a fuse, so I removed it. All of my vacuum hoses are new. And although my idle is still high (1146), I haven't been able to track down any leaks... The screw in the TB is all the way shut, and the knob on the FI box is all the way (oh jeez, which way was it ? - I think it was CW).

I adjusted the valves before the RRC (about 1000) mi of driving. That (simultaneously w/ timing) made a major improvement, as two exhaust valves were too tight. Towards the end of the RRC I did a little spirited driving (awesome) and on the trip home pushed kinda hard up a pass. Since then the engine has a slight roughness, so maybe valves need re-adjusting.

Anyway, the car idles at 1146 RPM, and the numbers there are : HC 1156 PPM (limit 600) and CO % 3.73 (limit 3.50). Of course, like an idiot, I didn't get the car fully warmed up before (it takes like 15 minutes of serious driving).





Anyway, my main goal right now is to get the thing to pass, fast and cheap. Failing that, if I put $75 into diagnosing the problem (at a legit business) I can get a waiver.
I won't need to do this again, as my county is cancelling its emissions program in Dec. '06

My other goal is to know what's wrong. I just got the car, and I know its burning a little oil (rings and/or valve guides) so I'm deciding how to proceed : I'm toying w/ a mild Subaru swap if I can do it cheap enough...


Any hints appreciated....

[dmenche914]

Build date and year model in many states are different, and year model is what most states use in determining smog rules. This is true in Calif.

Your idle is too fast for starters, so make sure your throttle valve is correctly shutting down, if it is, you might have a vacuum leak someplace, or running a bit rich.

Is your car catalyst equiped?

Some basic things you should do are check the compression, make sure it is good, else all bets are off on a cheap repair, so go for the $75 waiver, and save for a rebuild later.

What about the four plugs, how is the color, black and dry or black and oiley? or a nice dry tan color? I suspect black, cause running rich, hopefully dry which means it is not worn piston rings if they are black and wet, that means probably oil in the combustion chamber (compression test will determine cause) If all four plugs are black, they are all rich, which would mean a systemic problem (injectors firing too much, fuel pressure too high, or could start injector leaking) if only one plug is bad, then maybe it is cylinder specific like a leaky injector on that cylinder only.
You can test the injectors for leaks and drips by removing them from the manifold, keeping them connected to the hoses, and then prime the fuel pump by turning the key several times, let teh fuel pump run, and have a helper check for drips. As long as you do not crank the enigne, no fuel should drip out of them. (also test the cold start injecotr for drips this same way. just be away of fire, do this outside, have a helper to watch for leaks. have a fire extingusher handy.



You have a lot of unburned gas in the exhaust (high HC) and the high CO indicates that you have used up the Oxygen pretty much, cause if you had low CO (and higher CO2) that means you have enough oxygen.

Sounds like rich running rather than an ignition issue. If you had high HC and low CO that would indicate failure to ignite the mixture, as since the fuel did not burn, no CO would form, and HC would be high. (ie mixture could be correct, but spark failed to burn it)

However when HC is high, AND CO is high, that indicates too much fuel is being dumped into the system, it is burning, but not all of it, cuase there is not enough Oxygen to burn all the fuel, so unburnt (HC) and partially burnt(CO) gasses are produced.

Now with airpumps, if so equiped, a failed air pump can lead to higher CO and not effect the HC so much. If you run a catalyst, a failed cat will cause increases in HC, CO and if a three way cat NOx (NOx is also reduced by an EGR valve, although some cars get away with only a threeway cat no egr)

do you have the data on the other gasses measured (ie O2, CO2, NOx even if they passed)?

give us some more details if you have them on the test results,(and limits) and if you have a catalyst / air pump etc...





good luck

PS $75 is a deal to waive the smog. In my area Test Only cars (many older sports cars fall under this catagory) must get a special smog test and it costs nearly $75, if you fail, you got to spend like $100 trying to repair it, else they waive it for two years, then you have to deal with it in two years, only one waiver. also all 76 and later year model cars are required to meet these requirements forever, no future cut off age in sight. (and the same nazi's that came up with this (thanks arnold shwartznigger) want to add older cars to this program, we have to constantly fight them).

You is lucky in Colorado to have resonable (all relative here) smog laws.


good luck.