Gasoline smell after engine shutoff, 91 testarossa

I have smelled some gasoline coming out from the inside of air intake chamber after switching off the engine. There was no visible sign of gas leak anywhere. Any idea on where I should look? Thank you! Image Unavailable, Please Login

 

was the engine cold, warm or hot?

 

Can smell it both hot and warm

 

Leaking injectors would be my 1st uneducated guess. I would probably as an inexpensive and easiest 1st thing run a very strong carb /injector cleaner thru the system. Maybe the Lucas concentrate At a higher rate of cleaner. In the recent old days Bardahl use to make a cleaner that had some oil or lubricant in it and I swear it was the best stuff out there. That would be my 1st step. Thanks Mark

 

Swanson, I sent you an email and attached the supplement for section D of the WSM which gives a very good explanation of the fuel delivery in our cars. For anyone trying to find a leak it is not easy unless you have a good understanding of how the system operates and what components make up the system. The WSM and its supplements are great sources of information along with the people here. Good luck and please let us know what you find.

 

Could you possibly upload the supplement to your Dropbox account (or something similar) and post a link to it?

 

https://www.dropbox.com/s/xu895z81yqiwoou/Workshop%20Manual%20Testarossa%20Supplement%20Catalytic%20Converter.pdf?dl=0

 

mille grazie!

Something that I never noticed before is that the schematic on page D106 is for a physical configuration of "an F113B engine + cats with O2 sensors" which I think might be the very late euro TR "CAT" version mentioned in the TR SPC (although they mangled the English translation of it) - and not the US version schematic.

 

Fuel smell could be coming back out through the air intake box - which as Giallo Uno says is likely a leaky injector. It could also be coming from underneath the air intake system, lots of places to check there. First - check all fuel lines, filters, and accumulators running along each side of the engine bay. Then remove the air filter box and start looking under there. If nothing shows up, jack the car up, and from underneath...look up at the area in front of the engine, there are 2 cloth-braided fuel return lines that go the fuel tanks - check those. If nothing, remove the fuel tank protection plates and check the hoses at the fuel pumps, and the cross-connector hose between the fuel tanks. Hard lines don't leak very often, but over long periods of time the flexible hoses tend to rot from the inside out. If you smell gas when it's warm AND cold - you'd better find it before driving the car any distance.

 

Maybe the Cold Start Injector or Injectors are dribbling a bit??? You would smell them probably. If it was more than 1 injector leaking a bit and that particular intake valve was open........

 

Thank you all for the inputs. Will go back and check it again this weekend.
I can smell the gas only after switching off a hot or warm engine for a short period of time, but no a cold engine. The smell is from inside of the air intake box, not underneath it.
The injectors are all new, but will check them again. Also the lines near fuel tanks. Is checking the residual pressure a good way to tell if the injectors are leaking?
Any chance that a bad charcoal canister leaks gas vapor? Think there is a return line from the canisters to the air intake box.

 

the charcoal canister is plastic? may be broken. the non catalytic versions in germany have no charcoal canister so I don´t know if plastic or metal. but I don´t think that the smell coming from there

 

Did you take the air intake completely off and run the car? Remove the heat shield, the air filter box and the rubber boots other air metering unit and then run the car till it gets warm. Highly unlikely the lines from the charcoal canister are involved those lines are very small. Is your car running properly now? Does it idle properly from cold to warm up? If there are no signs of a leak in any of the connections, Unburnt fuel? 1-6 running rich? You need to provide some more info. Good luck.

 

The car is running properly. Idle also good, both cold and warm.
Will try to remove the air intake to see if possible to identify the leak.
For unburnt fuel, should be able to smell it even with the engine is running, right? I can only smell the gas after engine shut off.

Thanks.

 

Any luck?

 

Found something interesting...
The first picture showing a diagram of the connection from the charcoal canister that I found on the internet. The pipes from the canisters connect directly to the intake manifolds.

The second picture is the under side of the air intake box of my car. Pipe 1 & 2 are from the canisters, they connected together with a T joint and go into the air intake box before the air filter. Pipe 3 is connecting the two manifold ports (which according to the diagram should be connecting the pipes from canisters) together.

I'm not sure if it's different variations of Testarossa or the previous owner modified it. If the canisters connect to the air intake box like this, maybe it's possible for the gas vapor from the canister just escape to the air?

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could be. remove the airfilter cover and the air filter both sides and try to smell where it comes from. I would try this

 

That "CATALYST" diagram is for a US version TR (engine family F113A040) -- what is your engine family marking (the engine family marking is on the small raised plaque on the engine block just below the "1" and "2" labels in your photo)? Was your TR ever imported to a different market where it needed emission modifications?

 

It's a Japanese version, engine family also F113A040.
I saw some pictures of other Japanese Testarossas, the pipes are connected as the US diagram. Just no idea why mine is different, or the benefit of modification like this.

 

Do you have a brass nipple on each intake that’s open?

 

My car did the exact same thing years ago...

It was one of the tiny braided vent hoses running along the firewall... it was a complete bear to get to. When the tank is full, there is some gas that works its way up the vent hose. A small crack causes it to leak and evaporate, but not drip... It did eventually drip, and that's how I found it...

Get the car on a lift and look at the firewall...

 

Agree that it is then strange to not be plumbed the same as a US version, and would have the same sort of questions as Mr. Chairman:

On (page) Tav. 16 of the TR SPC there are the two fittings 24 and 25 (the picture shows them as being different shapes, but the text indicates that the same 125782 fitting is used in both positions on a US version). Are these fittings present, but blocked off? Or are the threaded holes for these fitting not even present (that could be the case if the upper manifolds are from a different version TR as I believe the same casting is used on all versions and then just some small machining details are different for different versions)? I'm assuming that the photo in post #1 is not your actual TR as that has the US fittings present. If it is your TR, where do those vacuum lines go if not to the charcoal canister?

With regard to your original symptom, having the charcoal canister lines connected into the airbox would provide a very direct route for fuel vapors to waft out the airbox snout (whereas, in the stock US location you've got the throttle plate in between and a much longer path) so not sure that you have a "problem" for the way it is plumbed.

 

No, the first picture was not car. Just got a picture from the internet to indicate the location. Since I don't have a picture of mine when writing that post. Sorry for the confusion.

Yes, fitting 24 and 25 were there, they were connected together by pipe #3.

 

Seems like someone was trying to "improve" things without knowing what they were doing . You could try just putting hoses #1 and #2 back where they belong to see if that reduces the fuel smell coming out of the airbox snout at engine shutoff.