Emissions: Passed in CA, Failed in TX, 89 Wagoneer

[navegare]

Just looking to get some sage advice on where/what I should start looking at. I bought this Wagoneer a couple weeks ago in the San Francisco area, it came with the emissions certificate below, showing it passed. Today it failed here in TX due to high CO readings at idle. Different tests, different requirements. I need a passing certificate to get the title transferred...

Waggy has a difficult time starting, cranks for a while and then gets going. I figured out that holding the pedal midway makes it start right up. A buddy says the accelerator pump might be leaking into intake manifold, pooling up gas there that makes it need more air on starting. It also has a hesitation off idle, kind of annoying while trying to back up a hill slowly and with precision-like with my enclosed (6x12) trailer attached or getting going uphill.

I filled up with Wally World gas (ethanol) out of convenience yesterday, I was already there. The Wagoneer is all stock, has catalytic converter, etc. Much stuff under the hood looks brand new: Air pump, hoses, filter, fuel filter, I replaced fuel pump myself.

Anyway, what do you guys suggest? Here's large scans of both tests, too complicated for my number-challenged head to make sense out of... I'm scheduled to take it this week to a shop where they said they'll tweak it and take it themselves to the inspection place until it passes. But I thought I'd ask here to at least have an idea of what to try myself to avoid getting skewered.

All input welcome, and thanks in advance...

This is the inspection report from June 6 in the San Francisco, CA area:
http://img833.imageshack.us/img833/5923/1989jeepgrandwagoneerem.jpg

This is the TX inspection report from today in Austin, TX:
http://img843.imageshack.us/img843/4927/1989jeepgrandwagoneerin.jpg

[billyrb]

WHAT EACH SECTION IS
HC: Unburned Gasoline
CO: Partially Burned Gasoline
CO2: Completely Burned Gasoline
O2: Oxygen, the Good Stuff
NOx: Oxides of Nitrogen (This is only seen by a 5-gas smog machine)

WHAT THIS MEANS ON YOUR RIG
HC: misfire or bad burn
CO: too rich
CO2: engine efficiency
O2: too lean or just air
NOx: too hot or too lean

Based on that, your truck is running too rich and not burning enough of the fuel. That means timing & carb. Set timing to around 10 degrees with the vac advance hose disconnected and plugged. Then, reconnect the vac advance hose. Next, take the carb and adjust the mixture screw in until the motor starts stumble, then back it out 1/4-1/2 of a turn. That should get you in the right ballpark, even with the other junk disconnected / etc. Also, drive it for about 30-40 minutes on the highway at / or above 45-50 mph solid before going back in for a retest. Next, when you get there (appointments help, as then the engine stays warm), you can ask them to run the emissions test in the "Test Mode" so you can see if it will pass or not before having the official test redone. That should save some time & $$.

Worst case scenario, set the timing to around zero degrees, and it should pass (it'll run like crap, but it should still pass) :)

[navegare]

Wow, thank you for taking the time for such a good explanation!

I'll go get a timing light (about time I got one and learned to use it) and do everything as suggested. It's only $1 each time I take it back to see if it passes, and I have 14 or so days to try stuff. So I get to learn and play with the Waggy and probably save a few $ in the process, what's not to like? What a great place this is.

I don't think I'll be taking it to the shop after all. Must... learn... myself...
I'll report back here with what happens over the next couple of days. :drivin:

[navegare]

Finally got the time today to go get the GW retested for emissions, and it Passed!

What did I change/do:

-Changed air filter. I should have never assumed it had been changed along with all the other new-looking bits under the hood. Lots of stuff was done by PO to have it pass CA emissions. I shouldn't have believed the report from the oil change place that it was OK either.
-Changed oil and filter (did it myself this time) mostly because it was due but I read somewhere on the board that it could help.
-Adjusted timing to 3-4* advance, vacuum advance hose disconnected, adjusted the mix screw as suggested by billyrb above (Thanks again!), and drove it for a good 30 minutes before I showed up at the testing place.

It was dying at stoplights while the A/C was on tuned like this, but it passed:

http://img840.imageshack.us/img840/5923/1989jeepgrandwagoneerem.jpg

I then came back and gave it a proper-like tune as per the VECI under the hood. It now seems to pull stronger than I remember, hesitation off idle is gone, and seems to start easier. I was getting consistent 14 1/4 MPG Hwy, so time will tell what this did to the economy.

Thanks again

[Edit:] 7/24/10 Drove 600 or so highway miles today. Got 15.2 mpg at 65-75 mph! But it dropped to 10 mpg while towing an empty u-haul car transporter for 100 miles, down to 8 mpg with a J20 on it for another 100 miles. I don't even want to think about city mpg. Whatever, I'm satisfied.