Slight smell of petrol fumes

jlo8872 · Postby **jlo8872** » Wed Feb 13, 2013 7:16 pm

Hi everyone,

Not sure if this is the correct place to post this; but here goes.

I have a 1997 NA8; I get a slight smell of petrol fumes when I'm crawling in traffic (top/hardtop up and a/con running) once the old girl gets a chance to strech her legs i.e. go above 60kph no more smell.

I'm wondering if anyone else has come accross this; and any possible solutions?
My gut tells me charcoal cannister; but am not certain.

J.

sailaholic · Postby **sailaholic** » Wed Feb 13, 2013 8:33 pm

The charcoal canister only holds the fuel vapour until a valve (forget the name) opens and allows the engine to suck vacuum through the canister. So it might be some of that gear leaking?

hks_kansei · Postby **hks_kansei** » Thu Feb 14, 2013 9:53 am

^ that

Or also possibly an exhaust leak.

If the gasket between the headers and cat is leaking the smeel will probably come up through the gearstick area (about where the exhaust/cat joins)

If the leak is pre-cat, or the car is cold, it will smell quite strongly of petrol.

bruce · Postby **bruce** » Thu Feb 14, 2013 9:58 am

Pop your bonnet and sniff. If it's in the engine bay it will be noticeable.
Otherwise it will be under your car via the exhaust.

project.r.racing · Postby **project.r.racing** » Thu Feb 14, 2013 1:49 pm

Exhaust leak before cat +1...

bear2230 · Postby **bear2230** » Sat Feb 16, 2013 9:51 pm

I had exactly the same symptoms about 9 months ago. Checked everything I could think of myself. I even gave it to a mechanic to check fuel lines under the car.
Finally after 2 weeks I found the cause……………. forgot to put the fuel cap back on last time I filled up……….

Richard
(Rocket scientist :lol:

)

mazmad · Postby **mazmad** » Sun Feb 17, 2013 6:32 am

Nice one

I get the same problem, but it is because there is often 2 5Gallon cans of petrol on the passenger side. And when there isn't the fumes are still there. It has gotten so I don't notice it now, and associate petrol fumes with fun times

Steampunk · Postby **Steampunk** » Sun Feb 17, 2013 10:01 am

This is getting lost in translation a couple of times, jlo are you talking about petrol fumes or exhaust fumes

manga_blue · Postby **manga_blue** » Sun Feb 17, 2013 12:08 pm

Steampunk wrote:This is getting lost in translation a couple of times, jlo are you talking about petrol fumes or exhaust fumes

No, they're right about a possible exhaust leak. The way the ECU worrks is that it constantly cycles between rich and lean mixture when running in closed loop (cruising) mode. This means that the cat gets a pulse of fuel following by a pulse of air. Burning the fuel off in the cat is what keeps the cat hot enough to do its job. So if there's a leak before the cat it may smell of fuel.

manga_blue · Postby **manga_blue** » Sun Feb 17, 2013 12:12 pm

Have you checked that the filler and vent hoses in the boot haven't been dislodged or damaged? You might have to remove a cover plate in the boot near the filler to see them.

jlo8872 · Postby **jlo8872** » Sun Feb 17, 2013 6:59 pm

People,

It's not the fuel cap; I've looked in the boot and all hoses etc. are connected.

Sorry to mislead anyone but it could be an exhaust leak; I work FIFO so am unable to check until I'm back in VIC.

Steampunk I think it is exhaust because there is a slight smell on my clothes after driving the car.

JLo.

project.r.racing · Postby **project.r.racing** » Sun Feb 17, 2013 8:31 pm

manga_blue wrote:
Steampunk wrote:This is getting lost in translation a couple of times, jlo are you talking about petrol fumes or exhaust fumes
No, they're right about a possible exhaust leak. The way the ECU worrks is that it constantly cycles between rich and lean mixture when running in closed loop (cruising) mode. This means that the cat gets a pulse of fuel following by a pulse of air. Burning the fuel off in the cat is what keeps the cat hot enough to do its job. So if there's a leak before the cat it may smell of fuel.

Bingo. Great explaination for those that dont know.

I'd hazard a guess that it is either a weld in one of the collectors has cracked or a metal gasket attched to the flexi pipe as burnt through.