Emissions test

[lxndr]

So, I've been trying to get my '86 CRX SI to pass emissions and it failed twice. I finally got it to pass on the third time around and I just wanted to share my findings in case someone else has the same problem and needs some help, or just wants to know what all that stuff on your emissions report means.

HC (Hydro Carbons) are unburned fuel.
CO (Carbon Monoxide) is partially burned fuel
CO2 (Carbon Dioxide) is a by-product of combustion
O2 (Oxygen)


1st time through with '87 Integra ECU and idle set at 1050 RPM (1100 limit):

HC cruise limit 220ppm, idle limit 220ppm.
I got 207ppm at criusing speed and 392ppm at idle. Failed

CO Cruise limit 1.6%, idle limit 1.2%
I got .73% and .71%. Passed

CO2
I got 14.93% and 14.51% N/A in Washington state

O2
I got .91% and 1.58% N/A



Second time through with '85 SI ECU and idle set at 840 RPM:

HC
219 and 308. Failed

CO
.76 and .61. Passed

CO2
14.86 and 14.61 N/A

O2
.98 and 1.35 N/A


After the first test I thought that the Integra ECU was allowing too much fuel to pass through the injectors, So I swapped it for a good '85 SI ECU. After the second time through, I realized that it must be a mechanical problem that is causing the high HC's. I checked my injectors and they seemed fine, so I checked the fuel pressure and it was perfect. After some head scratching I decided to swap out the CRX SI injectors for the only extra injectors I had that were for a D16A1 motor, then drove the car be tested again and it passed!

Idle 910 RPM.

HC
174 and 215. Passed

CO
.66 and .37. Passed

CO2
11.66 and 11.77. N/A

O2
6.02 and 5.55. N/A


I guess that even though the injectors checked out OK, one (or more) of them was dumping too much fuel into the cylinder.

Anyway , here are some possible causes for excessive emission levels:

HC: Mechanical/electrical failures, vacuum leaks, a very lean air/fuel mixture, timing, poor spark, and improper carburetor adjustments.

CO: Rich air/fuel mixture, poor emission control system, bad ECU.

CO2: Bad catalytic converter or exhaust leaks, poor air induction system.


I'm no emissions expert, I just wanted to share my findings on order to help others.

[cvcc_wagon]

good to know, i'm in the middle of getting the new little wagon to pass. everything was fine but the HC, limit was 260 or something in that neighborhood and the readings were 2000! (well probably more, i think the machine maxed out) before you sh!t your pants let me tell you why. my buddy was the one who took it through and he called me afterward telling me that it failed and it drove like crap on the way home starting just as he was leaving AirCare, when i got to his place after work i started it up and tried to drive around the lot (the farm in the pic above) and could hardly get it moving w/o stalling. (i should also mention at this point that one issue with the engine since we got it is that it shutters a little between idle and running rpm's, so basically as you take off it shakes a little and then evens out when you get up to speed, and if you sat there with the hood open and revved the engine would shake quite a bit till it hit maybe 3k or something. i thought maybe we had the timing belt off a notch after changing the head gasket so i played around with the distributor a little to see if it helped any [in the past i have been a notch off and either fully advancing or retarding the dissy tells you whether you are ahead or behind a notch] and it didn't. so yesterday i got some more oil thickener in there 'cause it was still smoking a bit at startup and a new set of spark plug wires and one new spark plug to replace the brand new one one i broke last week (d'oh) the engine revs nicely now with no shaking) anyhow back to the original story, i could barely drive it without it stalling and i have no idea how he drove it the 5 or 10 miles back home running like this. turns out the no. 2 spark plug wire came loose on the dissy cap so no.2 wasn't firing at all. i figured that's what must have failed it, nothing but raw unburnt fuel coming out...
so on saturday i will be running it through again, hopped up on 2 or 3 bottles of methyl hydrate... perhaps i'll disconnect and remove a few things as well

FYI, couple things that help pass emissions, higher idle=good, that's why there is a limit tho, up here there used to be a limit and they would actually take a rev reading before they would test you but now it's much more lax, i've taken my civic through at ~1300rpm for a couple years now. at low idle there is more chance of misfiring and generally things just don't burn as well. second is to retard the timing slightly but don't overdo it b/c the HC will go up.

i have posted on emissions in the past and did a wite up on how to clean out carbon build up with water thru a vacuum line (for us carb guys) it's a little out there but it has worked for me and the engine survived the ordeal. until i put the EK1 with sidrdraft webers my car never once failed AirCare (every year from 91 to 2004) here is the post

[lxndr]

Dude, stop sniffing gas fumes! Was that all one sentence?

[lxndr]

Do you think a little sodium bicarbonate would help with the water method?

[cvcc_wagon]

Originally Posted by lxndr

Dude, stop sniffing gas fumes! Was that all one sentence?

what can i say, i used brackets. you sound like the grammar police type users on on some other forums... at least i spell checked it.

Originally Posted by lxndr

Do you think a little sodium bicarbonate would help with the water method?

never thought of it. the explanation i was given for water is that it removes carbon buildup well and doesn't burn before it does the job.

[lxndr]

Originally Posted by cvcc_wagon

what can i say, i used brackets. you sound like the grammar police type users on on some other forums... at least i spell checked it.

never thought of it. the explanation i was given for water is that it removes carbon buildup well and doesn't burn before it does the job.

_eye gess thats troo# aye litlle bakingsoda en tha waiter mite bern en tha cylindar end kause mor deposets aind posseblie sum scratchis^ sorrie aboute thu grammer commant)

[cvcc_wagon]

not you're just picking on me...

[lxndr]

Originally Posted by cvcc_wagon

not you're just picking on me...

Don't you mean "NOW you're just picking on me"?

[lxndr]

You know this is all in jest right?
You're still my buddy.

[cvcc_wagon]

the 78 passed AirCare yesterday!