Failed California Smog

[greenchevy]

1989 Jeep Wagoneer Limited 4.0 inline 6

Hc(PPM) readings

Max GP Meas
Idle-580 120 270 355
2500 RPM-2657 180 330 97

CO(%) readings
Idle-580 1.00 2.50 .23
2500 RPM-2657 1.00 2.50 2.89



What would cause me to fail HC(PPM) at idle but pass at higher RPMs?
What would cause me to pass CO(%) at idle but fail at higher RPMs?

I figured if it was the cat i would have failed everything.

[4.3LXJ]

How long since you changed the O2 sensor? Also, when smogging, run a can of SeaFoam in a 1/4 tank of gas. Then refill with premium. That is what the smog boys do here.

[greenchevy]

I've changed the o2 sensor probley 3-4 years a go.

[xj4life2]

Change the o2 sensor and get the idle speed up ,580 is to low thats why you failed HC's at idle,the co was more than likely a bad o2. but to be sure give me rest of the specs and i can diag it here. Joshua tree , your a basic area ?
Mark

[prcjeep]

Hope you can pass next time without too big of a bill! I remember the CA smog tests. My 92 blazer failed it and I didnt get around to fixing it before it was totaled. Less stringent smog tests out here in TX

[AJ99]

or i have a "smog" cat in my garage lol but im in bakersfield..... Whoops did i just say that... :bang: LMAO

[greenchevy]

You don't say where in bakerfield ?

[greenchevy]

The rest of the smog info



RPM %CO2 %02
MEAS MEAS
IDLE- 580 12.06 4.7
2500 RPM- 2657 11.68 3.0

[AJ99]

north of the river lol... aka OILDALE!

[greenchevy]

So far a bad 02 sensor and i need to figure out why my idle is to low. I know that my butterfly when closed still lets air through. Would a leaking throttle body butterfly cause my low idle?

[4.3LXJ]

I would suggest you remove and clean your idle air control. Cheap fix and almost always works

[xj4life2]

Doesn't look like the cat is lighting , Fax me a copy of the VIR at 530-895-8015. I'll let me smog techs have a look see but I would say o2 , clean IAC and cat

[greenchevy]

Sure I'll fax it to you in the morning. The idle air control valve is brand new installed it probably a week ago. Took the throttle body off and cleaned it up. The tps is adjusted to spec.

[Brasscatz]

So far a bad 02 sensor and i need to figure out why my idle is to low. I know that my butterfly when closed still lets air through. Would a leaking throttle body butterfly cause my low idle?

I wouldn't think more air getting through would cause lower idle because the butterfly opens up when you increase throttle, thus making your idle higher. Forgive me but I do not know how the '89 is set up.... but is there a screw or some sort of adjustment on the throttle body/throttle cable that could adjust your idle higher? I don't know if that would help your problem at all or not. These other guys definitely know way more than I do on this subject. Good luck though!

[xj4life2]

I wouldn't think more air getting through would cause lower idle because the butterfly opens up when you increase throttle, thus making your idle higher. Forgive me but I do not know how the '89 is set up.... but is there a screw or some sort of adjustment on the throttle body/throttle cable that could adjust your idle higher? I don't know if that would help your problem at all or not. These other guys definitely know way more than I do on this subject. Good luck though!

If you take the throttle body off there is an air bleed screw than you can adjust however.... the computer will take over and put it back to where it wants it. The IAC controls air and fuel based on the signal from the ECM along with the TPS. Cleaning the carbon build up out of the IAC port in the TB and the pintel on the IAC is the first place to start. You can also manually pull codes (very primitive, but there) to see if the offending sensor has logged a code. To be more specific to answer you question, if the IAC has a carbon build up it may be getting to much air by not allowing it to close all the way.

[xj4life2]

Shift transmission into Park, shut engine off and raise hood.
Throttle Cable Components

Press cable release button.
Throttle Cable Adjustment

Push cable conduit back into cable sheath as far as possible.
Rotate lever on throttle body to wide open throttle position. Cable will ratchet to correct adjustment point as lever is rotated.


This is how the cable is adjusted properly , Good Luck

[xj4life2]

Ok here's the general concensus from my smog techs, Lean misfire, to much air, bad o2 and bad cat. Lastly idle to low. One thing to check is the PCV system. Check the line from the back of the valve cover to the intake. It MUST be clear. If the oriface in the valve cover is dirty you can use carb leaner on it. Next the nipple on the intake manifold must be open , use a 1/8" drill bit to be sure it is clean.Blow through hose and all to be sure the vac. can flow through. this may solve you idle and air issue all at once if there is a restriction. Use carb cleaner and shoot around the TB and listen for change in rpm, fix if you find one. A cat you can pick up at NAPA fairly cheap. O2 at any parts house , I prefer the factory Jeep one but any one will do for now.

[Brasscatz]

Ok here's the general concensus from my smog techs, Lean misfire, to much air, bad o2 and bad cat. Lastly idle to low. One thing to check is the PCV system. Check the line from the back of the valve cover to the intake. It MUST be clear. If the oriface in the valve cover is dirty you can use carb leaner on it. Next the nipple on the intake manifold must be open , use a 1/8" drill bit to be sure it is clean.Blow through hose and all to be sure the vac. can flow through. this may solve you idle and air issue all at once if there is a restriction. Use carb cleaner and shoot around the TB and listen for change in rpm, fix if you find one. A cat you can pick up at NAPA fairly cheap. O2 at any parts house , I prefer the factory Jeep one but any one will do for now.

You're a good man, Mark. I don't care what anyone says about you :smiley-whacky119:

[xj4life2]

I do what I can , and as for what everyone says about me .... Its only 'cus thier to scared to turn thier eyes inward and see themselves as they really are. Glad to help a brother out anytime !!!

[greenchevy]

Thanks so much for the help. Im going to replace the cat and o2 sensor. I checked the hose in the back of the valve cover and no restriction. I checked the throttle body for leaks didnt find and.

[greenchevy]

Ok so i replaced the catalytic converter and 02 sensor. Replaced wires and plugs, cap and rotor. Had the ignition coil checked and its good.Still has a misfire. Where to look?

[Brasscatz]

Ok so i replaced the catalytic converter and 02 sensor. Replaced wires and plugs, cap and rotor. Had the ignition coil checked and its good.Still has a misfire. Where to look?

Did you gap the plugs to spec? Also making sure all the plug wires are all the way seated. I suppose you could have a clogged injector on one of your cylinders, too. Other than that I can't think of anything else at the moment.

[greenchevy]

plugs are gaped. i tested the injectors and they all read 16 ohms. Injector 2 and 3 gave me problems i had to keep moving the meter probe around till it would get a stable reading. Then i looked at the injector connector plugs and plug 2 and 3 were all corroded like on a battery. So I'm assuming my misfire is from the corroded connectors so I'm going to order 6 new ones.

[4.3LXJ]

Start the engine cold and run for 10 seconds. Then shut down and feel the exhaust runners for heat. The cool one will be the one that misses. Then pull the plug and start the engine to see if it sparks. If so, probably fuel related

[greenchevy]

What do u mean by runner?

[4.3LXJ]

Your exhaust is almost a header. Maybe I should have said header tube.

[greenchevy]

I started the engine and pulled off one connector at a time. When i would pull a connector off each injector the idle would get worse. But on the second injector when i pulled off the connector it didn't change the idle. So im assuming that my misfire is on the number 2 cylinder. Im going to pull the fuel rail, move the injector and see if the misfire moves.

[XJ Wheeler]

I would do what Steve suggested by seeing if there's spark on that one. That's quicker and easier to tell if its spark or fuel delivery than dealing with injectors.

[greenchevy]

Yea i actual checked that and didn't post it but i have spark on that cylinder.

[greenchevy]

fixed misfire, did tune up, replaced catalytic converter and 02 sensor. failed CO% and HC(PPM).

co(%)
Test RPM MAX GP MEAS
IDLE 620 1.00 2.50 6.36

2500 RPM 2370 1.00 2.50 9.54

hc(ppm)
Test RPM MAX GP MEAS
IDLE 620 120 330 203

2500 RPM 2370 180 270 153

I did put 3m fuel tune up kit. it has a can of throttle body cleaner,bottle of engine combustion cleaner, and a bottle of fuel injector cleaner. The combustion cleaner goes in the brake boost vacuum hose, the throttle body cleaner is self explanitary, and the injector cleaner goes in the gas tank. Maybe the cleaner hasnt worked its way through the system?

[4.3LXJ]

The cleaner may affect emissions until it is done going through. Run it down to empty and fill again.

[xj4life2]

Cleaner shouldn't run the co's up that high , its way to rich and not burning it. With a new cat I would have never expected those numbers. I also noticed that the RPM are very low at Idle. I'll do some checking and see what I can come up with

[4.3LXJ]

Mark, if I remember he bought a used cat. Might be the problem.

[xj4life2]

could be but its not in fuel control or the fuel pressure reg is blown and is pushing strait fuel down its neck, with the CO at 6% he would tear up at cat. i would check the fuel reg and see if its good if it is he may have a bad comp. Need a data stream to confirm but fuel control is the issue . Pull the vac line on the regulator you should not see,smell fuel and be sure you have vac at it. Other than that your back to not going into fuel control.

PS . SHHHHHH its illegal to install a used cat on a vehicle in CA.

[greenchevy]

Bought a new cat and installed it. not used.

[4.3LXJ]

Sorry

[greenchevy]

Pulled vacuum on the pressure regulator and it holds with vacuum pump. Not sure how much pressure I'm supposed to pull from it but at 5psi it holds with no drop. I then hooked up a fuel pressure gauge and the needle (shakes) around 32-34psi. When i accelerate the fuel pressure will go up 2 or 4 psi then it will go down (bellow idle psi). When i let go of the accelerator it will go back up to 32-34psi. When i turn off the engine the fuel pressure will rise to 40psi.When i pull off the vacuum from the fuel regulator the psi goes to 40psi.

[greenchevy]

I've lost 26 psi with the engine off in 30 minutes.

[4.3LXJ]

Are you running premium or regular gas when testing?

[greenchevy]

Regular

[4.3LXJ]

Our gas contains ethanol. The greenies think this is supposed to lessen our dependence on foreign oil and lower our carbon footprint. However ethanol makes gasoline molecules sticky and they don't evaporate as well and so don't atomize as well. So in effect we take a milage hit because some of our gasoline ends up being burned in our catalytic converters instead of inside the cylinders. One trick the smog guys have for marginal vehicles is to burn premium instead of regular. I do on all my vehicles when I smog. So use up your gas and then refill with premium.

[greenchevy]

Could a faulty coolant temp sensor or manifold intake sensor cause my high CO%? What symptoms do these sensor cause when faulty?

[4.3LXJ]

Faulty coolant temp sensor will make it run rich

[greenchevy]

How can I test it and where is it? Is it in the engine block?

[4.3LXJ]

The CTS is in the thermostat housing

[greenchevy]

My hell is over. Jeep passed smog with flying colors. everything was super low. i ended up changing the temp sensor, tps, iac, intake/exhuast gasket( 1cyclinder had a leak), changed the donat on the end of the intake/exhuast manifold, my throttle body butterfly adjustment screw was messed up so i replace the trottle body,changed 02 sensor, new cat and muffler, changed a leaky freeze plug there is probly more just can't remember. thanks everyone for the help. Old jeeps never die they just get rebuilt.

[nickyg]

The easiest way would be to move to North Carolina, They'll pass it here even if it's running on coal.

[89Laredo]

Our gas contains ethanol. The greenies think this is supposed to lessen our dependence on foreign oil and lower our carbon footprint. However ethanol makes gasoline molecules sticky and they don't evaporate as well and so don't atomize as well. So in effect we take a milage hit because some of our gasoline ends up being burned in our catalytic converters instead of inside the cylinders. One trick the smog guys have for marginal vehicles is to burn premium instead of regular. I do on all my vehicles when I smog. So use up your gas and then refill with premium.

One of our gas stations had a sign up a while ago for "rec gas", 90 octane no ethanol. If its not too much more expensive I'm going to try a tank full and see what kind of a mpg change it makes.