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A smoggin' I will go...

ParadiseXJ

ParadiseXJ

NAXJA Forum User
Location
Paradise, CA 95969
I'm heading to the smog station today with the MJ. 88, 4.0, 5 spd. This baby hasn't been smogged or registered since 2007.

I have done:

O2 sensor
Coolant Temp Sensor
All engine vac lines, CCV etc.
All HVAC vac lines
All T/C vac lines
Cleaned out the valve cover & baffles
New gas cap
Charcoal cannister lines
Checked EGR and EGR solenoid function

Plugs, wires, rotor, fuel filter, changed oil. Radiator, hoses, pump etc.

What have I missed. Any red flags??

Engine runs great, doesn't overheat, this is CA so there's no "inspection" other than under the hood and the gas cap. The rest of the truck is a work in progress.
 
Drive it on the freeway a bit before you bring it to the station, throw a can of that GTP stuff in it, maybe clean the throttle body?
 
Well, the MJ was about to pass with flying colors. All the engine test came out clean as a whistle. The last test, CA emissions Evap. Pressure Test. FAIL.

The problem is that there are 2 vents in the top of the tank, each has a hose to it, they tee off and go into the vapor return line to the charcoal cannister. In the test they pressurize the tank and pinch off the return line at the cannister. If the tank holds the pressure for ~2 minutes, you pass, if not FAIL. That is you fail the whole thing, no smog, no registration.

So I dropped the tank. There are 2 grommet dealio's that have a nipple on them for each of the vent hoses. One of them is gone, one is broken. Does anyone know what these are called, where to get them or ???.
 
I think they are rollover valves but I'm not sure. If joe peters doesn't have the info (I know he found it at one point) I'll try and remember to look it up in my parts catalog at work tomorrow.
 
what would stop you from plugging one and allowing the other to run to the charcoal canister? As long as it's vented and still sealed when the hose is pinched, no one would know if there were one or two vents.
 
Shorty said:
what would stop you from plugging one and allowing the other to run to the charcoal canister? As long as it's vented and still sealed when the hose is pinched, no one would know if there were one or two vents.
Click to expand...

I am leaning towards the plug idea. I think just one vent would do. Both for the test and functionality. Maybe some RTV??
 
pull the vent and replace it with an "expanding freeze plug"-- one of those that you tighten a nut to expand-- best chance that it'll seal. Stick the tank back up and "play stupid" if something still fails.

I'd change the gas cap as well, since it is responsible for sealing/venting the filler neck on the tank.
 
You need two of each:

J536 0058 VALVE
J536 0059 SEAL
 
joe_peters said:
You need two of each:

J536 0058 VALVE
J536 0059 SEAL
Click to expand...

Aaaaand Joe wins! Those are the numbers.

Per the OP, fuel filler cap already replaced. Feel lucky, I had to replace my filler neck as well due to a rust hole, not because of smog restrictions but because the MJ smelled like it was gonna explode!
 
joe_peters said:
You need two of each:

J536 0058 VALVE
J536 0059 SEAL
Click to expand...

...are those dealership numbers or ??

NAPA had no idea...well they had an idea...but they've "never carried them". Is it possible to do a "hardware store" fix on these? At this point I'll do whatever it takes, even a new tank since this one is 22+ yrs old. I just wish the PO hadn't futzed with it.
 
Those are MOPAR numbers - you can google for them (take out the space) and any number of sellers will appear. Morris 4x4 appears to have the valves for $11 and the seal (which has been superceded by 5201 8823) is the same.

Looks like the seal can be swiped out of 93-96 ZJs as well, and my SWAG is that 84-96 XJ ones will work too. The valves are listed as being the same as 84-96 XJs, so the junkyard may be a good place to head for.
 
I'm glad my 88 eliminator is registered historic, so I can avoid inspections all together, although it'd pass before my 96 and m3 would.
 
ParadiseXJ said:
Well, the MJ was about to pass with flying colors. All the engine test came out clean as a whistle. The last test, CA emissions Evap. Pressure Test. FAIL.
Click to expand...

CA started using the Low Pressure Fuel Evaporative Test (LPFET) in 2008 to test the integrity of the evap system. This test is done only on vehicles older than 1995. After that, OBD-II tests the readiness of the evap and they take it's "word" for it.

You mentioned you changed the canister lines. I did on mine as well before smogging last month. I noticed one of the lines had a small restrictor in it. It went into the nipple on the canister, but it pulled off with the hose. Luckily I saw it and put it back in. Not sure what effect it has but it listed in the parts guide as a metering plug.
 
ParadiseXJ said:
...are those dealership numbers or ??

NAPA had no idea...well they had an idea...but they've "never carried them". Is it possible to do a "hardware store" fix on these? At this point I'll do whatever it takes, even a new tank since this one is 22+ yrs old. I just wish the PO hadn't futzed with it.
Click to expand...

Yep, dealership. I see Kastein has posted up some good additional info for you.
 
That's great...all the info on this...I called the dealership with great reserve, but, here tomorrow ~50+ for both sets...grumble grumble, smile, smile.

The silver lining here is that I KNEW beforehand that I needed at least one of the vents and I was waiting to do it before I put my brand new (JY) steel tank skid under there. I just didn't even think about that particular piece flunking my smog test. So now I have another %^!@#$ project...yay!!

Thanks guys!!
 
Saudade said:
You mentioned you changed the canister lines. I did on mine as well before smogging last month. I noticed one of the lines had a small restrictor in it. It went into the nipple on the canister, but it pulled off with the hose. Luckily I saw it and put it back in. Not sure what effect it has but it listed in the parts guide as a metering plug.
Click to expand...

It's an 0.050 metered orifice BUT in the Hayne's manual (I know, I know) the .050 orifice is in the small hose. I found mine in the larger hose. I'm befuddled as to it's REAL location. I don't even know if it makes a difference which side it's on. I think it's purpose is to only allow just enough vacuum to clear the tank of fumes or just enough the charcoal cannister can take, even in a "low vacuum" situation as it's not hooked up to the vacuum reservoir and relies only on intake vacuum.

Anyway I replaced the vent/rollover valves, hooked it all up, ready to try smogging again. I only had to drop the tank about 1/2 way to reach the valves.

My original numbers were great, the only snag was the tank pressure:
At idle - CO2=14.4 02=0.3 HC = 32 CO = 0.16
At 2500 RPM - CO2 = 14.5 02 = 0.1 HC = 29 CO = 0.17
 
Last edited:
According to the emissions label the orifice should have the line the runs to the fuel tank, not the line to the intake.

And good luck on the test--don't stay up all night cramming for it, old fart!
 
This old fart passed smog today. Everything was tight. Now I can sleep (except for the numerous spontaneous naps I take throughout the day which my employer doesn't even know about).
 
This old fart passed gas today, but I blamed it on the dog. :D
 
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