AMC Eagle Den Forum

The Mighty 258 => Emissions/Vacuum Systems => Topic started by: zboot on November 09, 2015, 07:32:09 PM

Title: 83 Wagon Fails Emissions
Post by: zboot on November 09, 2015, 07:32:09 PM
So, the new 83 wagon failed emissions testing. Gas cap not holding a good seal (easy enough fix) and CO emissions were high (3X the limit).

Given that the NOx and CO2 emissions were within tolerance, my current gut feeling is that the emissions system is mostly ok and I'm just running way too rich. I can get re-tested for free within 10 calendar days so my first task will be to check engine timing and adjust the carb mixture screws. I'll also look to see if there is a relatively inexpensive meter I can buy to at least let me know whether changes I make are moving me in the right direction.

I likely also need to ensure I do everything else to adjust for altitude (car was previously in STL area, now in CO)
Title: Re: 83 Wagon Fails Emissions
Post by: vangremlin on November 09, 2015, 07:41:53 PM
I live in CO also and had a 78 Gremlin that failed emissions.  I took it to a friendly shop that set it up so it was very lean so it would pass emissions, and they said to bring it back after the test and they would re-set it up so it would run better.  Its also a good idea to change the oil before the test, that will help with the emissions.

I had a friend who was having problems with emissions test on an old car, and I think he said he put a lot of ethanol in the tank.  You can also try some of this, which has a lot of good reviews on Amazon and is available locally at OReilly's.

http://www.amazon.com/CRC-05063-Guaranteed-Emissions-Formula/dp/B000CIPUR8/ref=sr_1_1?ie=UTF8&qid=1447123176&sr=8-1&keywords=guaranteed+to+pass+emissions

Where you at in CO?  I live in Centennial.
Title: Re: 83 Wagon Fails Emissions
Post by: eaglefreek on November 09, 2015, 08:02:54 PM
When I lived in CO, my Eagle failed emissions. I had the Carter rebuilt and it still failed. I put in 5 gallons of E85 with an almost empty tank and passed with flying colors. No guarantee this will work for you, though.
Title: Re: 83 Wagon Fails Emissions
Post by: JayRamb on November 09, 2015, 09:38:24 PM
A friend of mine put a lot of SEAFOAM in the engine with the tank about 1/4 full, leaned it out as well.
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 09, 2015, 11:36:46 PM
When I lived in CO, my Eagle failed emissions. I had the Carter rebuilt and it still failed. I put in 5 gallons of E85 with an almost empty tank and passed with flying colors. No guarantee this will work for you, though.

I saw your recommendation earlier in another post. I'll likely do this in combination with advancing the timing and adding the high altitude jumper to the ECM.

I live in CO also and had a 78 Gremlin that failed emissions.  I took it to a friendly shop that set it up so it was very lean so it would pass emissions, and they said to bring it back after the test and they would re-set it up so it would run better.  Its also a good idea to change the oil before the test, that will help with the emissions.

I had a friend who was having problems with emissions test on an old car, and I think he said he put a lot of ethanol in the tank.  You can also try some of this, which has a lot of good reviews on Amazon and is available locally at OReilly's.

http://www.amazon.com/CRC-05063-Guaranteed-Emissions-Formula/dp/B000CIPUR8/ref=sr_1_1?ie=UTF8&qid=1447123176&sr=8-1&keywords=guaranteed+to+pass+emissions

Where you at in CO?  I live in Centennial.

I'm in Arvada. If my first pass doesn't work (I've got a free re-test so why not), I'll try your friendly shop. Heck, it may be good to have their details for other purposes too :)

It feels good to be back in an Eagle!
Title: Re: 83 Wagon Fails Emissions
Post by: vangremlin on November 10, 2015, 01:30:19 PM
Good luck!
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 15, 2015, 11:42:55 AM
Quick question, where do I find the high altitude jumper on my 83 wagon? I pulled the plastic covering over the ECM, and didn't really see anything there. I see a connector taped near the firewall on the wiring harness going to the ECM. It's a two terminal connector, one side has a black wire, the other side has two red wires. I'm hesitant to jumper that just on a guess.

Anyone know offhand what it looks like or have I already hit gold?

EDIT: With the engine running, I read 13.5v across the connector, so it's likely not the high altitude jumper. The search continues. Well, in a few hours, currently building a gate. ..
Title: Re: 83 Wagon Fails Emissions
Post by: mo.eagles on November 15, 2015, 05:11:25 PM
In the Epedia under 15 Diagrams  ,CEC section ,1983 6 cyl ,  bottom right of the page it shows a 2 wire connector with a black wire and 2 pink with  stripe wires . It should be right next to the MCU . In the service manual I have it just says there is a two wire connector next to the MCU but does not give any colors of the wires.
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 15, 2015, 06:46:14 PM
In the Epedia under 15 Diagrams  ,CEC section ,1983 6 cyl ,  bottom right of the page it shows a 2 wire connector with a black wire and 2 pink with  stripe wires . It should be right next to the MCU . In the service manual I have it just says there is a two wire connector next to the MCU but does not give any colors of the wires.

Thanks. Looking at the diagram, one of the two pink wires goes to the diagnostic connector. If it matches up, then I'll take a chance that it's the correct connector.

EDIT: That was it! Thanks!

Now I just need to get the idle back to normal :)
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 17, 2015, 10:08:57 AM
So, the fast idle was set fine, though my electric choke isn't actually working so I'll have to investigate that soon. I set the curb idle with the car in drive. I couldn't set it to 550 like it says on the sticker or between 650-700 like I've read in other places - just stalls out as soon as I add some extra load (like power steering). So instead I set it to the minimum where I could steer to near full lock without stalling - ended up being about 850. This then results in the idle (in park) after the engine warms up of about 1400.

We'll see how things go today with emissions (running half/half E85 to 85). If it fails, I think I'll skip straight head to the Howell TBI kit. It's been on my future upgrade list and it seems slightly wasteful to invest too much money trying to get this to pass emissions on the carter when I could install the TBI kit and likely have a much easier time. I've got a bit over 50 days left on my temp tags so that should be sufficient :)

EDIT: And life get's better! I found my TSM. Apparently, I'd stored it away at work. Must have come here one weekend to work on an SX/4.
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 18, 2015, 12:31:26 PM
So failed emissions again. This time it was because:

1. CO was high, though 40GPM (limit is 30) down from 110 on my first test.
2. O2 sensor "not present". I'll be able to check things this evening. I didn't force them to give me a definite answer on this since I'd failed anyway, but I'll double check that I didn't disconnect wires or something in the process of doing other work.
3. NOx was high, just barely passed the limit. This was way below the limit last time, so it may be related to the O2 sensor (if they are correct in that there was something wrong and not that whomever did the visual inspection this time didn't know what they were doing).

In any case, I think I can get the CO numbers lower. I've got a couple ideas in mind including limiting the accelerator linkage. I'm pretty sure anything past 75% throttle is just leading to more unburned fuel.
Title: Re: 83 Wagon Fails Emissions
Post by: mo.eagles on November 18, 2015, 03:52:19 PM
Back when I had to test my ride ( now pre '95 is exempt ) and it was that close , I would fill the tank with the highest octane I could find . Drive it for 1/2 tank then retest . Worked every time . Do they probe the exhaust or run it on a dyno?
Title: Re: 83 Wagon Fails Emissions
Post by: AMC of Houston on November 18, 2015, 06:30:42 PM
Just for grins, look down the carb while at warm idle and see if you see any drips of fuel from the venturis (venturae??).   Slightly clogged idle bleed tubes can cause a rich mixture condition, and keep you from getting the curb idle speed down where it should be.
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 19, 2015, 12:47:24 AM
Yeah, I think running w/ half a tank of E85 helped me get the CO number down to where it is.

I got a chance to take a closer look this evening and yes, the O2 sensor is "not present".  There are pieces of an incredibly rusted out sensor there - most of the metal body (where you'd stick a 7/8" or 22mm socket on) is gone. I'll need to pull the EGR valve and most of the tubing there out of the way so I can soak it in PB blaster then get my torch in. If I'm lucky, the little bit of metal left will be enough to get a vise grip onto and twist out. Otherwise, I'm going to have to pull the exhaust manifold.

Given the O2 sensor's role in closed loop control, that may explain why my curb idle problems.
Title: Re: 83 Wagon Fails Emissions
Post by: carnuck on November 28, 2015, 09:59:30 PM
CO too high usually means the motor isn't warm enough to switch to closed circuit, which also means the O2 isn't online. The high altitude thing may shut off the O2 sensor info as well. Not sure. A voltmeter will tell you if the O2 is working or not. I used to use a sweep meter and it would flip back and forth pretty fast. (like an on/off switch)
   I cross wire the dist to make it backfire and that cleans out the idle tubes. Dirty motor oil raises the CO as well. I temporarily plugged the PCV on mine and rerouted it to the ground for the test.
Title: Re: 83 Wagon Fails Emissions
Post by: zboot on November 30, 2015, 02:57:08 PM
CO too high usually means the motor isn't warm enough to switch to closed circuit, which also means the O2 isn't online. The high altitude thing may shut off the O2 sensor info as well. Not sure. A voltmeter will tell you if the O2 is working or not. I used to use a sweep meter and it would flip back and forth pretty fast. (like an on/off switch)
   I cross wire the dist to make it backfire and that cleans out the idle tubes. Dirty motor oil raises the CO as well. I temporarily plugged the PCV on mine and rerouted it to the ground for the test.

Yeah, the O2 sensor issue was that the entire sensor was rusted out. Essentially all I had was a small amount of sensor housing left. There's too little metal left to grip onto so my option now is to use a bolt extractor and/or left hand drill bit to get it out. I've got time to try and remove what's left (I've got a low profile angle head drill on the way) and put in a working sensor. I also need to do an oil change so that should help. Given the improvement between my first and second test with the CO numbers, I'm pretty confident that I can get it to pass - either by actually fixing the problem or with a combination of the workarounds you and others have suggested.
Title: Re: 83 Wagon Fails Emissions
Post by: mo.eagles on December 02, 2015, 09:47:06 PM
 zboot , just ran across a TSB in the shop manual  that says when you add the high altitude jumper (with auto trans) to change ignition timing to 16* BTDC . Just thought you would like to know.