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....

[jsteele22]

Wow,

A lot to catch up with !

Yes, the car has an air pump. One of the air injectors is missing and
that port sealed off.

Ben Said :

> Your car is burning quite a bit of oil. Like I mentioned in Moab,
> mostly on decel. But after following you for a few (hundred) miles, I
> notice that you burn oil most heavily on hard acceleration (up Vail
> pass for example) and on deceleration, but there is still noticeable
> smoke (sometimes) when we were just cruising. I have a feeling this
> may be your biggest hurdle to passing the test.


So the car is burning oil. (Time to switch back to dino ..) I can't
see any smoke when I drive, and the car passed the "viusal" test fine,
but Ben and others at RRC mentioned it. It makes sense to me that that
could cause excess HC.

Ben again :

> When you check your timing, look for the marks at the back of the
> impeller, closest to the engine. You really have to crane your neck
> around to see them, but you should have a white one for TDC (or a 0)
> and a red one for 27' BTDC on the 2.0.

As for the timing, I originally looked pretty closely for the marks and didn't see
them. I was looking on the "outer" surface of the impeller, that
faces up as you look in the hole. This is where it would line up with
the little notch in the stationary part of the housing. Are you saying
that they are on the narrow vertical surface facing the rear of the
car ? I'll have a closer look-see.

As for adjusting the timing, does it make any sense to go "by ear" :
i.e., adjust slightly BTDC/ATDC to tweak the idle ? Again, I don't
*think* I have any exhaust leaks, but I'll sure check again.... The
car idles at around 800 when totally cold, but it goes up after that.
And yes, when I did the timing, the car was totally warmed up and
distributor vac line (to retard) was pulled and plugged.


Catalytic converter is there, that's about all I know. The EGR valve
is hooked up, but the plumbing stops at the firewall; i.e., no exhaust
gas actually gets fed in. This shouldn't be the cause of the high
idle, as it feeds in pre-throttle. If anything, my uninformed guess is
that this would cause engine to run lean, since O2 is not being
displaced by exhaust gasses. (But I never understood the idea of EGR)

No info on exhaust O2, NOx. Exhaust CO2 is 3.8% at idle, no limit
indicated.

Cap'n : The AAR port is blocked off. Also you mentioned setting valves
to .016" . That's way looser than the Haynes value (.006/.008",
IIRC). Is this suggestion for emissions testing only, or for general
operation ? Having larger values here means the intake/exhaust valves
open less and for shorter duration, right ? Wouldn't that effectively
make the engine run *more* rich ? (less air, same fuel).


Here are my conclusions/hunches so far :

* High HC is probably due to buring oil, due to bad rings/valve guides.
* Idle setting on FI box is too lean, causing misfiring, causing high
CO and high HC.
* Valves need adjusting again.
* I need to spend $75 and get the waiver ! (Too bad I replaced all the ignition stuff already...)