gvnc

I've got an '01 XJ.

Occasional in-cab gas smell is what I want to fix. Seems to happen mostly on long trips, pretty much only when the car is running, mostly with driver's window down a bit. I thought running the ac made it worse, but now I'm not sure. It doesn't happen all of the time, seems like giving the engine a lot of gas (like if I floored it, then came to a quick stop) brings it about, but maybe that's a no-brainer.

First fear was leaky injector-- I can't see/smell any problem there. Did a fuel leakdown test on the rail and it passed. I also had this problem before and after replacing o-rings, but I could've screwed up the job. I noticed a previous owner had upgraded to some ford injectors and they weren't as snug as I would have liked, but seemed ok.

Had recurring evap codes, replaced the gas cap twice. First from autozone, but then getting lots of fumes and when filling up the pump was clicking off-- presumably because the charcoal canister was getting clogged up or something. I was going to replace the charcoal canister before I read somewhere to get a cap from the dealer instead of the piece of junk I got at autozone. Mopar gas cap solved those issues, but not the occasional in-cab smell. Could the charcoal canister still be the issue... I know the vent line is right by the fresh air intake, but whenever I jam my nose over there I can't smell gas.

I've checked my lines best I can, which probably isn't good enough. I've resisted paying for a smoke test so far, also don't have a trusted mechanic here yet and can't afford to leave the car at a shop for days.

My airbox/filter smells like gas. What's the deal with that? I have read conflicting stuff online.

Had an o2 sensor code but cleared it and it hasn't come back. I have 4 o2 sensors on my 01, so don't want to replace those unless they need to be done. Also, my gas mileage seems pretty good... like 19+ highway I'm pretty sure.

Also have this annoying long crank time to start that I've been dealing with, which may or may not be related.

Sorry that's a ton of stuff. If anyone has thoughts on how to troubleshoot this mess, I'm all ears.

Love this forum, lots of good info. Thanks in advance!

InitialForce

With the air box and filter smelling like gas, sounds to me like gas is making it into the crankcase and the oil which in turn the vapors get sucked into your air box by the crank case vent line coming from your valve cover into your air box. Check your oil dip stick and see if it smells like gas. You may be suffering from the nutorious 00-01 cracked head problem

Start with that and rule out the oil getting contaminated because the in cab smell sounds more like a leak in the fuel system somewhere which its possible that its just sucking vapors out of the engine bay into your air filter.

The charcoal canister purge line shouldn't be dumping into the air normally. If i remember right thats an overpressure safety system so check the purge valve for the canister. The PCM will normally open the valve and your intake will suck up all the vapors in the canister and recycle them. There is a metal line that runs the back of the eninge bay. Check all those hoses and the line going from the canister to the intake.

gvnc

Thanks for the reply.

How much gas smell are we talking about on the dipstick? It doesn't smell strongly of gas... but maybe a tiny bit? I forget exactly how many miles since last change... at least 5k, possibly 7k, so it's overdue and it just smells kinda noxious to me.

How do I check the purge valve on the canister? We're talking the charcoal canister underneath the vehicle or the evap canister under the hood?

I'll go spend some time checking lines and report back.

toasterknight

Factory recommendation for oil change for normal duty is 7.5k

gvnc

Thanks toasterknight, that's good because that's probably about how often I do one.

No new finds on hoses/lines, but if I've got a pinhole leak I doubt I'll find it. I've wanted to build a smoke machine design I saw online (paint can, wire, mineral oil, battery power, air compressor with regulator), but not sure where to get all the parts now that radio shack is kaput, and it might just be better to pay a shop.

Researching cracked heads now. I'm not losing coolant as far as I can tell, so that's a good sign. I replaced the valve cover gasket/ccv tubes/grommets a couple months ago (wish I'd inspected the head closely then!) and didn't see any green or anything sludgy. Oil pressure stays steady, not noticing any power loss.

Would a compression test absolutely rule out a cracked head?

I'm thinking next time I smell gas I can pull over, stop, pull the hose that runs from the front ccv tube to airbox and try to smell for gas without passing out.

What are the evap components (aside from lines) that I can/need to check? Purge solenoid does click once it's warmed up. That's all I got.

toasterknight

If it makes you feel any better I run to 10k with delo 400xle 10w-30 and an extended volume filter.

InitialForce

Everything I've read, if it's a cracked head or you have major blow by causing gas to go into the oil it will be a strong smell on the dip stick and oil. If you aren't loosing any coolent and the oil and coolant don't look contaminated I would pursue a leak somewhere first. Does it smell like straight gas when you smell it or could it be that you are smelling an exhaust leak and unburned fuel from the exhaust maybe? The exhaust does a turn to the passanger side under the motor

The valve can be tested by applying ground and positive and blowing on one side to make sure it opens and closes like it's supposed to.

gvnc

I think I've ruled out cracked head for good. I did a compression test and it looks great. All between 140 and 160, no two adjacent cylinders have a difference of more than 10 or 15 psi I think. (3 and 4 were 140 and 150.)

Exhaust leak is possible. I don't think that's what I'm smelling but won't rule it out yet.

I think a smoke test is necessary. I'll go to home depot tomorrow and see if I can concoct something based on other people's designs.

Also, putting things back together after the compression test, I realized the wiring harness (plastic connector thing) that plugs to the ignition coil pack is making a crappy connection due to broken plastic-- big chunk missing from the first time I replaced the spark plugs. I'm wondering if it's a problem. But if I was losing spark I'd probably be misfiring?

I think this weekend I'll try to build a smoke machine. Hopefully it'll cost less than paying someone else to do the test.

Also randomly got a p0194 code (which shouldn't happen on a this vehicle) and a p0140 which is another o2-related code. These occurred when I was cranking and the coil pack wasn't plugged all the way in, so I'm going to delete and ignore for now.

kdexter89

I had a very similar experience in my 01. Had gas smell but could not find the leak for a long time. It never dripped on the ground and evaporated fast enough not to leave a wet spot. there was a small (really small) hairline crack in the stainless steel line that goes form the injection rail down along side the intake and connects to the rubber line on the frame. The crack was caused by prolonged engine vibration. Mine cracked where it attached to the intake with the clip. I hope this helps.

gvnc

Thanks for the idea. How'd you find it in the end? Dye test?

I put an oz of uv dye for gas in the tank with about 4-5 gallons left, drove it for a few miles, can't find any leaks. Might not have driven it long enough, but crawled around tracing the lines from the tank and can't see anything. I'll try again tomorrow after driving it more.

But if that ain't it I'm left with evap stuff and exhaust leak. Still need to smoke it... would that turn up an exhaust leak? I don't understand how much of the system can be filled with smoke from the lines running in/out of the solenoid.

JandDGreens

One day I noticed a gas smell in my cab also. I only drive it occasionally. It seemed to run OK, in fact it ran very good so I did not worry to much 'cause it wasn't that bad.

Then one day it developed a miss and I decided a compete tune-up was in order. So I purchased a complete Accel tune up kit and also a Accel ignition coil also. I had my son-in-law do the tune up since he good at it and I was to busy. When he pulled the distributer there was two contacts that were completely burnt away, so two cylinders were not burning any gas. The exhaust had enough gas fumes in it so make the smell. After the tune-up the smell went away.

JandDGreens

I did not see until I checked your profile that you have a 2001 and no dist. But that is what I found was my issue and could still be a possibility that the problem is with your coil pack were one is not firing and un-burned gas is going into the exhaust system???

kdexter89

I had my wife cycle the key on and off to engage the fuel pump while I checked everything over. I had the air filter box and air horn off the intake so I could open the TB and smell in there for leaky injectors. After cycling the key about 30 or so times I happened to look at that line and saw a drip of fuel on the bottom of the clamp. I took the line off and made a new one using the old one as a pattern.

gvnc

I'm not getting any misfire codes, though. Also the spark plugs all look the way they should and very similar. If a cylinder wasn't firing because of the coil pack, then it wouldn't be sparking, and the plug would look different... right? Maybe I'll pull the coil pack today and test it/inspect. Any idea if the boots just pull straight off?

gvnc

Pulled the coil pack, pulled the boots, contacts all look the same, a little dirty. Gonna leave those alone. Pulled the boots, got the voltmeter out. Admittedly I have no idea what I'm doing, but set the dial to 20k in the Omega section (that's for ohms, right? Is that resistance?) and got ~16.4 readings for 1 and 6, 2 and 5, 3 and 4, and nothing in different combinations. So I think that means the pack is ok.

Once it's dark out I'm gonna have another go with the uv light.

Still thinking evap or exhaust at this point.

It's hot out and crank time to start is getting longer, which I don't like but have no idea if it's related. Poor man's prime has no effect.