Fuel smell and check engine questions

You'll want to pull your computer codes for your 5-8 ECU for your starting point.

A 5-8 Slow Down light, rather than a Check Engine light, when combined with a smell of fuel would lead one to think that you are sending unburned fuel to the driver-side cat (e.g. bad spark plug wire, coil, bad spark plug, etc.).

The smell of fuel is not to be ignored. It indicates a potentially life-threatening problem.

After checking your computer codes, rub one finger all around the screw-on connectors for your 2 fuel filters, top and bottom on each, plus around your connections on your fuel pressure regulators and fuel rails front and back of engine, both sides.

If you can smell fuel on your finger after doing the above, then you've identified one or more fuel leaks.

Inspect your black fuel vapor cannister next.

After you've performed the above inspections and retrieved your computer codes, you may have enough information to post here to get some help on what to do next.

In the meantime, don't drive your 348 while you smell fuel (i.e. until you've done something positive to fix this problem).

 

Also, check here: http://webpages.charter.net/aircover/348/1994Ferrari348Spider.html#FuelSmell

 

Funny thing that fuel smell, my 348 gets the same only when I fill her to the brim,you didn't fill yours the same did you. I smell petrol in the cabin when I used to fill her to the top but as soon as the petrol gauge droped from the full mark the smell would go away and wouldn't return until I filled her up fully again. Checked over for leaks like "No Doubt", actually lost count of how many times my brother and I checked over the system for petrol leaks but still couldn't find the problem so good luck with yours

 

Hey Pap, you're the man!

...but I'd still check to see if your fuel overflow tube was clogged!

 

Hey now your making me blush

Yeah I will do and let you know, thanks

 

4114 is your Top Dead Center recognition. Well, if your spark plugs aren't firing at the correct time due to lack of correct TDC recognition, then it's pretty easy to imagine that you'd be pumping large amounts of unburned fuel into your cats.

...BUT... you'll always get the 4114 error code if you checked your codes with your engine off rather than when the engine is running. So was your engine on (i.e. is the code real) or is the code simply confirming that you checked ecu codes with the engine off?

1211 and 1212 codes are your Motronic ECUs' way of saying that they can't lean or enrichen your air fuel mixture enough to bring your exhaust anywhere near desired tolerances, and from a real 4114 code above, you could see why!

If 4114 is not a real code, then I'd look at your lambda components (O2 sensors, MAF electrical connections, MAF resistance - should be 383 ohms on both MAFs) as well as your spark plug wires, spark plugs, and coils.

On the other hand, if 4114 is a real code (i.e. appeared when checking codes with engine running), then I'd take your car to a dealer (gasp!).

Likewise, you still need to check for fuel leaks.

 

(in a meek, very unsure voice)

A little bird told me the car idles rough, runs up to 1200, drops to 900, back up, etc. when cold. Has trouble starting. Also, the little bird told me this car might have experienced some DX side non impact trauma prior to the current owner.

So, at the risk of being proven completely wrong and a total dumbass, I'll say meekly...



'phase sensor'




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Phase sensor or wiring going to/from phase sensor (or crank position sensors) seems like an educated place to start checking to me too, Daniel.

However, the engine codes are just one aspect. They may or may not be causing his fuel smell. That's a serious enough issue that he needs to manually inspect for fuel leaks...one finger at a time (on each fuel connection).

 

One thought on this thread as I read it I had the same issue on my TR and could find no visible leak anywhere it turned out to be a fuel hose the one from the filler neck to the tank that had deterioated over time and was allowing fumes to seep through the wall of the hose enough to smell but not to show liquid but as previously stated its a dangerous situation so I pulled forward my major service which was due next year and had all the fuel hoses replaced as part of the process.

 

That's probably the right call for the TR. However, on the 348 you can replace that filler neck without pulling the engine. It does go to a location in front of the engine, but it's off to one side enough to reach.

In fact, all but 2 fuel connections are in front of the engine. If you can smell fuel in the rear of the engine instead, then I'd look at the two fuel rail connections on the back (for full-on leaks), or at the cats/exhaust (i.e. unburned fuel being dumped).

It's not out of the question that you could smell fuel from your cats, for instance, if you've got a failed O2 sensor. You'd smell that at the back of the car rather than in front of the engine (don't use the finger-fuel-smelling trick on the cats!). In that case you might not even have an actual fuel leak, just excess fuel being dumped through the exhaust (which could potentially catch a cat on fire).

 

for anyone that keeps his gas tank topped off most of the time and the car has some reasonable miles on it the charcol cannister will go and you will get a strong smell of gas. easy replacement and not expensive