Failed Smog - Need solution or sale

[88trailcrawler]

My XJ is an extra car, used by my Highschool kid. (We love it, but don't really need it.)

Failed Smog today:
CO % measured at
- 0.94 @ 15mph
- 1.26 @ 25mph
Max is 0.75/0.95

NO (ppm)
- 1094 @ 15mph
- 1107 @ 25mph
Max is 714/616

Notes from technician:
- Emmissions
- Overheating
- Canister and vacuum lines
- Idle RPM at 1100

I need to figure out a solution but can't justify putting much into this jeep at this point. Part of me wants to just sell it and be done.

So I turn to Naxja for solutions, how do I keep my XJ on the road?

 

[sidewaysstarion]

Looks to me like you have a dead catalytic converter.

I'd also check the bolts on the intake manifold, you might just have a simple vac leak leading to your high idle.

 

[GrimmJeeper]

^ he's on the right track. your high idle is likely due to a vacuum leak, the notes about the evap canister and lines could have something to do with it... it could be something as simple as a cracked, broken, or disconnected vacuum line. high numbers across the board is usually a bad catalytic converter as well.

 

[88trailcrawler]

Hydrocarbon measurements:
- 63 @ 15mph
- 94 @ 25 mph
Max is 124/104 (pushing it at 25mph)

I can't find any rattling or indication of loose stuff in the Cat, it is 5 years old.

I don't hear any Vac line leaks.

Damn thing just ran up to Tahoe, wheeled for a week and ran home (500+ miles each way) no problems.

I can't afford to just start thowing parts.

Best option would be to find a reasonable and fair mechanic or shop that knows how to test and diagnose before just starting to swap things out.

 

[GrimmJeeper]

Best option would be to find a reasonable and fair mechanic or shop that knows how to test and diagnose before just starting to swap things out.

Someone will probably post his contact info after I mention this but the best guy near you to call is mike finch. Good work at a fair price and he knows xjs just abaout as good as anyone I've ever met.

 

[88trailcrawler]

Thanks Grimm.

I already texted Mike (he's done work on my XJ in the past)

Still gotta figure out where to start.

 

[GrimmJeeper]

I personally would start by trying to track down your high idle. follow every vacuum line you can see and every 4-5" give it a little pssh pssh from a can of starting fluid. do the same for any place a vac line connects to the motor or another line. if the idle jumps up you found a leak.

it's cheap and it's a good place to start. on my MJ I had leak problems at the vacuum manifold on the front of the intake manifold where all the vac lines come together. it's a two piece unit and mine was leaking in between them.

 

[my2monkeys]

Did it fail the EVAP Test? This is the test that pressurizes the fuel tank to see if it holds for a certain amount of time.

My 89 failed the EVAP Test and it was the grommets on the roll over vents on top of the tank. Sealed them with RTV and passed the retest.

Maybe post in the OEM Tech for more answers on Emissions fixes.

Good luck

 

[IslanderOffRoad]

I'm betting cat, especially if overheating is involved.

I had no rattling in my 94s cat but it was pretty close to clogged shut... I'd get overheating on inclines at higway speed. Feel the seat bolts for the passenger seat while the vehicle is hot. If they feel hot you probably need a cat

 

[88trailcrawler]

Thanks guys! Super helpful.

The XJ is sidelined for now. Going to do the following first:
- change out coolant tank (cracked) and refill coolant so I can run it.
- starter fluid vac line chase down
- check cat temp.
Won't get to it untill next weekend, I'll report back.

Just looked closer at visual inspection report:
FAIL: fuel cap functional ????
FAIL: fuel evap. Controls
Disconnected: Vac lines to sensors (I think he is wrong)
FAIL: other emissions related components

 

[IslanderOffRoad]

Fuel cap functional means your cap is leaking/not sealing. New cap should fix it

 

[SanDiegoOverland]

Threadjack: My rig's using a bit of oil either via the valve guides or the rings. Ya'll think thats going to effect my smog test? I know that the oil in the exhaust can clog up the cat, but otherwise would it show up on one or more of the tests?

 

[Carol.92124]

Well, FWIW, my 1998 Mitsu Mirage, at 208,000 hard-earned miles, leaks oil about as fast as she burns it (she's leaked for the last 70K+ miles, and burned some for the last 30K or so--not clouds, just oil residue across the back bumper & such). She <squeaked> thru smog this last May; we got it good & warm first.

 

[SciGuy]

Well, FWIW, my 1998 Mitsu Mirage, at 208,000 hard-earned miles, leaks oil about as fast as she burns it (she's leaked for the last 70K+ miles, and burned some for the last 30K or so--not clouds, just oil residue across the back bumper & such). She <squeaked> thru smog this last May; we got it good & warm first.

That makes a big difference.

Catalytic converters are more efficient when they're piping hot... One of my buddies had an Astro van he was trying to smog back in highschool. He called the smog shop and told them to be ready for him to pull up on the dyno as soon as he got there. He lived about 6 miles away, and drove to the smog shop in first gear. Passed just fine after failing a week prior.

I can't say I remember how bad he was failing before he did this trick but it did work. Not the right way to fix the problem but it was a proper bandaid...