Ticking time bomb TICK TICK TICK: Spark plugs Alert Alert Alert!
- Thread starter 2001LC
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I just checked under the hood and couldn't smell any gas. All the hoses were dry.
I did smell some gas under the left rear tire yesterday..but I closed the gas cap and haven't smelled any gas near the tank today.
Today I did smell some gas in the cabin while driving... but it's gone away at the moment..
2001LC
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- Thread starter
- #144
While replacing plugs I suppose one could damage a return or vapor hose on DS.
When you smell stop, open the hood and smell and smell around the gas tank. A raw gas leak is very dangerous. In 98-02 more vapor stuff under hood on drive side (DS). 03-07 much of this was moved to rear above spare tire DS. Some have reported hole in gas tank or rather fittings on top of it.
But often we get a raw gas smell during warm up. This come from tail pipe. If you've a seal leak at rear hatch, doors or windows this can get into cabin. Or rust hole in under or lower body. Very dangerous. As other times when CATs heated up you'll not smell anything.
When you smell stop, open the hood and smell and smell around the gas tank. A raw gas leak is very dangerous. In 98-02 more vapor stuff under hood on drive side (DS). 03-07 much of this was moved to rear above spare tire DS. Some have reported hole in gas tank or rather fittings on top of it.
But often we get a raw gas smell during warm up. This come from tail pipe. If you've a seal leak at rear hatch, doors or windows this can get into cabin. Or rust hole in under or lower body. Very dangerous. As other times when CATs heated up you'll not smell anything.
There is a small hose crack on this pipe. I covered the hole with the clamp. Not sure if this is what you are referring to.
What year is your truck? If 98-02 check all small hoses on drivers side around char can and that system. Its not likely the hose you circled but if cracked you are probably due to replace all of those medium size vac lines.
you can smell it in cabin with windows up or down? I had a fuel leak in my 80 right after the tank in the rear and you could smell it strong doing 30mph with the windows down. Thats how strong it would be. It wont leave a wet mark if the truck has been off for several hours. You would have to start it up and immediately watch under the hood with a good flashlight andonly run it for a minute. Did you disconnect any elec or vac hoses? Probably around the rear cylinders or the entire passenger side?
you can smell it in cabin with windows up or down? I had a fuel leak in my 80 right after the tank in the rear and you could smell it strong doing 30mph with the windows down. Thats how strong it would be. It wont leave a wet mark if the truck has been off for several hours. You would have to start it up and immediately watch under the hood with a good flashlight andonly run it for a minute. Did you disconnect any elec or vac hoses? Probably around the rear cylinders or the entire passenger side?
2001LC
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- Thread starter
- #147
No he's talking about little 4" long next to it, your fine.
I don't see throttle cable so you've a 03-05.
That said all you don't want any vacuum leaks, which that hole you cover may be. Also I see what looks like old PCV hose on PS. It's the large hose forward attached also to air box. That hose once removed from engine head cover always are bad at this age, if factory. Also the one of DS head cover.
I don't see throttle cable so you've a 03-05.
That said all you don't want any vacuum leaks, which that hole you cover may be. Also I see what looks like old PCV hose on PS. It's the large hose forward attached also to air box. That hose once removed from engine head cover always are bad at this age, if factory. Also the one of DS head cover.
Edit: it might be that hose. Sorry on the phone. That clamp is no longer clamping anything if its that high up. Does the crack go all the way through?
2001LC
SILVER Star
I noticed in my truck I get fuel smell when removing intake. Not in normal operation.
Is that normal? I was thinking it's coming from inside throttle body (leaking injector?? which I cleaned all) but now it sounds like it might be from vacuum hose I have to disconnect to remove intake?
Is that normal? I was thinking it's coming from inside throttle body (leaking injector?? which I cleaned all) but now it sounds like it might be from vacuum hose I have to disconnect to remove intake?
2001LC
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- #151
Let's be clear. You should never smell fuel from under the hood.
One exception may be (I've not seen/smelt) on the 98-02 which has charcoal canister (CC) under the hood. A very small puff may come from top of that area, once in a while. But still you'd not smell that in cabin unless open hole in fire wall. But issue with 98-02 CC are rare, we see more with 2003 up, from over filling gas tank.
Most time, actually we are smelling gas from tail pipe.
When I pull intake, fuel rails, fuel injectors, etc. I always replace any and all gasket removed with OEM. This includes washer on fuel rails, which are gaskets. I always replace any cracking hoses. But have yet to see a bad fuel delivery hose.
I've had engine that just really produced so much gas smell, I can't stay in garage even with doors open. Did everything to tune them, all 8 FI's sent out to be rebuilt, all new seals & gasket, hoses, spark plugs, MAF oil & air filters. You name it, it was done. Improve smell from exhaust but did not eliminate. Then add a new set of Denso coils to the mix, and no more fuel smell.
I've one now have one all was done, except FI (fuel injectors). It is exhaust is still smelly. This may be FI's, weekend compression or may be tires old CATs. I plan on doing FI next.
Bottom line; fuel smell from exhaust can be mix or one just issue. They are very common and not a big deal.
But a raw gas smell anywhere getting into cabin can be very bad and very big deal. It needs correct ASAP.
One exception may be (I've not seen/smelt) on the 98-02 which has charcoal canister (CC) under the hood. A very small puff may come from top of that area, once in a while. But still you'd not smell that in cabin unless open hole in fire wall. But issue with 98-02 CC are rare, we see more with 2003 up, from over filling gas tank.
Most time, actually we are smelling gas from tail pipe.
When I pull intake, fuel rails, fuel injectors, etc. I always replace any and all gasket removed with OEM. This includes washer on fuel rails, which are gaskets. I always replace any cracking hoses. But have yet to see a bad fuel delivery hose.
I've had engine that just really produced so much gas smell, I can't stay in garage even with doors open. Did everything to tune them, all 8 FI's sent out to be rebuilt, all new seals & gasket, hoses, spark plugs, MAF oil & air filters. You name it, it was done. Improve smell from exhaust but did not eliminate. Then add a new set of Denso coils to the mix, and no more fuel smell.
I've one now have one all was done, except FI (fuel injectors). It is exhaust is still smelly. This may be FI's, weekend compression or may be tires old CATs. I plan on doing FI next.
Bottom line; fuel smell from exhaust can be mix or one just issue. They are very common and not a big deal.
But a raw gas smell anywhere getting into cabin can be very bad and very big deal. It needs correct ASAP.
Not in cabin. Not from exhaust, but feels like from open TB. I can smell it when I turn engine by hand, for example rotating crank to verify alignment marks produces puff of smell. Nothing that didn't go away but I didn't smell it on other engines
@2001LC
I waited for engine to get cold and restarted it. Immediately smell some strong gas around the gas cap area. When I opened cap, there was release of vapor pressure.
It's very windy today but I didn't notice any strong gas smell from under hood.
Cold Exhaust... maybe a gas smell? I can't tell today.
Haven't smelled inside cabin since this morning..
I waited for engine to get cold and restarted it. Immediately smell some strong gas around the gas cap area. When I opened cap, there was release of vapor pressure.
It's very windy today but I didn't notice any strong gas smell from under hood.
Cold Exhaust... maybe a gas smell? I can't tell today.
Haven't smelled inside cabin since this morning..
So bad coil can cause fuel smell from exhaust, but not from engine bay?
2 of my coil was in bad shape with carbon dust. Some of the rubber rings seemed a little stiff but no cracks
How is your engine running after the work you recently did?
The coils having carbon on them is really not going to dictate if the coil is in bad shape or is failing. I have an original coil in my LC with 182k on it that was badly dried out by having a loose plug. With a new NGK plug boot/gasket on it to replace the cracking ones, it is still performing flawlessly.
Cold starting an older vehicle will produce a gas smell from the exhaust on very cold days. Motor runs rich because the block is cold, and the exhaust isn't warm either so there is going to be a certain level of unburnt fuel until the ECU can lean out and the cats warm up.
The gas cap pressure is interesting as the evap system should allow the tank's pressure to equalize. This could be the source of your smell but I'll wait for others to chime in as I have no direct experience with that outside of pulling my gas cap when I'm at altitude to let it balance.
2001LC
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- Thread starter
- #157
Normal. Just intake valve open at a cylinder that had unspent fuel.
A slight release of pressure from gap cap is normal. To much may indicate a return pressure issue. Make sure you are not smelling fuel form exhaust or it's tail pipe and thinking gas tank area. Wait until engine warmed up. Best is after a HWY drive. This heats CAT to operating temp. Then smell near exhaust pipe while engine idling. If exhaust does not have fuel smell, but you smell around gas cap/tank. You need to find out why. Not likely a leak, or you'd not get any pressure release. So may have and over pressure issue.
Yes coil can cause fuel smell form exhaust. They would not cause any fuel smell under the hood. But a loose spark plug could. Neither would cause near gas cap.
Coils don't have to be bad, to the point of failure. IMHO they get weak with time and some may not fire as well. If I know everything else is in great condition. That is to say; a very well tuned engine. I smell fuel at exhaust after warm up. I do a little driving test. I jump on it hard getting on the HWY. Floor it up to 60, 70, 80, 90 even 100 MPH from ~30 MPH. If as I accelerate getting near 50, 60 ,70, 80 MPH, I feel a string of almost inappreciable hesitations as I accelerator. That is almost always weak coils. I slap in a new set of Denso coils and fuel smell from exhaust gone as is any hesitation.
But as I said I've one now with new coils in, but Fuel Injectors (FI) not rebuilt yet. No hesitation but, fuel smell form exhaust is higher than I like. Next I'll do FI and see if improves. If not, next will be fuel pressure regulator. Not then either, them I've only two things left. Neither will I do anything about. CAT are just getting less efficient or compression to low for a real good combustion or both.
For you, with high pressure at gas cap and if fuel smell is indeed around gas cap or fuel tank area. Makes me wonder if PO or you've over-filled the gas tank. Since 2003 when charcoal canister was moved to the rear in 100 series. Toyota came out with a warning, which is in your OM. It states "stop pumping gas into gas tank, at first auto-shut off of gas pump handle". This is a big deal. If tank over-filled it can dump raw fuel in charcoal canister, they than may need replacing
@boobird what year is your truck?
you might just need a new OEM filler cap. if you are in NY, today was the first real cold day and that is gonna have some effect on the tank pressure. and i see some cracks at the end of some of your other hoses, so it would be good to start replacing those. they deal with the fuel vapor and pcv system.
you might just need a new OEM filler cap. if you are in NY, today was the first real cold day and that is gonna have some effect on the tank pressure. and i see some cracks at the end of some of your other hoses, so it would be good to start replacing those. they deal with the fuel vapor and pcv system.
When I replaced the spark plugs as 120K in the 01LX the plugs were tight, appeared normal and only slightly worn. The miles were predominantly interstate travel. I installed the Denso SK20R11 plugs purchased at Toyota using the snug 1/4 turn approach. I did not notice any improved performance with the new plugs, I was impressed, the originals could have gone much longer. Similarly replaced the plugs at 230K with none loose and plugs appearing normal. I have been highly impressed with the Denso long life Ir plugs. Additionally, there has been only 1 failed coil so far. I used only a slight touch of anti-seize. Previously, on other vehicles I had used the Denso platinum plugs since the 90s. Now my 07LX is ready for plugs and I got the new Denso TT plugs from Lexus, they are made in USA. Based on this thread, I will pay attention to the looseness of the plugs when I install them.
The Denso Platinum plugs had a 60k mile service while the Denso long life iridium plugs have the 120k mile service (Toyota and Lexus). Denso also marketed another iridium plug with 0.4 mm tip that was rated for 60K miles, while the long life 0.7 mm tip was the one for 120k miles. This explains the conflicting service life regarding iridium plugs. The new TT plugs with 0.4 mm and a split tip appear to land in between the other two Denso Ir plugs, so I plan to use 90k miles as a target.
The Denso Platinum plugs had a 60k mile service while the Denso long life iridium plugs have the 120k mile service (Toyota and Lexus). Denso also marketed another iridium plug with 0.4 mm tip that was rated for 60K miles, while the long life 0.7 mm tip was the one for 120k miles. This explains the conflicting service life regarding iridium plugs. The new TT plugs with 0.4 mm and a split tip appear to land in between the other two Denso Ir plugs, so I plan to use 90k miles as a target.
Do you know if this boot kit (671-8184) good for a 2006 LX? I've searched on denso products, and this part number only fits 2007 cruiser and LX. I'm not sure what to believe..
