Club 80-90 Forums

I have a constant smell of fuel in the engine bay. When the engine's stopped the smell emanates from the side vents.

I sniffed all around the engine bay and have isolated it to the area around the front of the carb. This could include the carb, fuel pump or re breather tower. I checked the fuel pipes around that area but nothing is wet. I'm stumped now. Is there any trade tricks to find the leak? A cigarette lighter could be used but I fear it'll end in a Hollywood style explosion!

Have you tried checking for leaks with engine running? I once had a fuel line with a pinhole in it that only showed when pump was going.

Bubble Meister wrote:isolated it to the area around the front of the carb. This could include the carb, fuel pump or re breather tower.

Just point out that the breather tower is to the rear of the carb, not the front. However, I am not just being "picky", it could come from the tower. Check the condition of the air filter (which the tower breathes onto). If it looks at all wet and smells of petrol, then check this = whilst the engine is cold, start it up, then run it for no more than 5 minutes. Then pull the dipstick and rub the oil on it onto your fingers and sniff it. If that smells of petrol you may have a leaky fuel pump diaphragm which is allowing petrol into the sump, and then evaporating out, via that breather. Not overly common, but worth checking (as petrol in your oil is not good).

CK - sorry, I forgot to mention that. Yes I've ran the engine and checked all the obvious places and pipes.

Ghost - agreed that technically the tower and fuel pump are rear of the carb with ref to the van. Interesting you say about fuel in the oil. Last week I moved my van to do an oil change - the engine was running for about 2 mins cold. Once the oil was drained it distinctly smelt of petrol. I put this down to the quick run (normally I run the engine hot before dropping the oil)
If I remove the pump will the petrol be obvious, running down the shaft?

Umm, sounds like that might be it, but remote diagnosis is not an exact science.

Bubble Meister wrote: If I remove the pump will the petrol be obvious, running down the shaft?

Sadly no, that won't be obvious. Now, I have never tried this, but I wonder if blowing down one of the petrol pipes on the pump might reveal a leaky diaphragm. I don't think it's a very reliable test, but it might show up summat. A new pump would of course take away any concerns on that score.

Just had to move the van to get another car off the drive - lifted the dipstick and the oil has a light fragrance of fuel. I've just noticed there is oil on the engine block, the obvious source is the base of the breather tower.
I have a spare pump so I'll fit that and re-seat the breather tower. I'll inspect the air filter too.

So the breather has been cleaned and reseated (snapped the plastic ring at the base n had to super glue it)
I fitted my other fuel pump (sadly not pierburg like the original). I replaced two fuel hoses (this pump's ports face a different direction and I suspect the pump outlet hose of chafing on the carb support bracket). I inspected the air filter which was clean. Took for a drive and the fuel smell has gone away!
Realistically I think it was failure of the pump that was causing fuel to get into the oil and then the smell oozed out of the fill up point. If I get chance I'll try and prove the pump dealing failed.

and change the oil at first opportunity

Thread resurrection!!
It's smells of fuel again. I fitted a Brickwerks budget fuel pump last year but it started smelling again. I changed the oil last week before a week long holiday covering 1100 miles. But almost immediately (after only a few miles) the smell was back.

I can only think of two possible oil contamination interfaces: the fuel pump and carb. I'm tending towards the carb now: at idle the exhaust gas is stinking despite the plugs being healthy and achieving 24mph on holiday. I wonder if the idle is shot or, whether fuel is entering the induction system overnight and getting across the piston rings.

Has anyone got any advice? Can the carb leak fuel that can ultimately get into the oil system?