fuel entering air ceaner

Howie44 · 08-27-2008, 10:14 AM

Have a 97 Sierra and after running for a few mins can smell fuel.
When I remove the air hose from the top of the cylinder head cover that runs to the air cleaner (With a T split to the PCV), I can see a mist of fuel vapour coming out.
Any idea's why this is happnning an how to fix?
-Is it fuel pump membrane broken and fuel entering through the camshaft?
-Or is it coming froma faulty PCV?
-Have I stuffed up a hose on the carby and mixed a fuel hose with an air hose?
-Or something else?

thanks in advance.

chelerizr · 08-27-2008, 05:27 PM

faulty pcv for sure

Howie44 · 08-28-2008, 09:58 AM

replaced pcv -problem still there.
runs well for 5mins+ then starts running badly and fuel mist entering air cleaner.
next step?

fishjoe · 08-30-2008, 08:51 AM

Is there any other problems other than the smell???? Is the engine running smooth and nicely? Can you feel any power loss? Is there any smoke come out from exaust pipe?? Finally, are you sure the smell is from the air intake not any where else on the engine??

I would guess, the smell is from somewhere else and the oil mist should not smell like strong fuel smell. I am not quite sure about this paticular motor but generally a little oil/fuel vapour coming out from PCV is usual, but surely not as bad as you can smell!!!!

I might be wrong since I know more on deisel engine than petrol. Excessive vapouration usually indicates the damage on the engine. You need to be aware. Take the pcv off, run the engine and see if the fuel is pouring, spreaying out? or just a bit smoke or few drops occasionally which is normal.

If you checked every thing and they are all fine, fit a catch can might solve the vapour problem.

Howie44 · 08-30-2008, 09:09 AM

Have literally just walked back in the door after a test drive.
-Took the carby and manifold off of the block and replaced the gasket between the block and manifold with gasket goo.
Gave the carby a good clean out & then put the carby back on and re connected all of the hoses -pretty sure they were right the first time, but fairly sure they are now anyway.
Now the problem has gone away.
I need to rasie the idle speed slightly, but other than that it runs ok now.
It's my sisters car and I've only driven it a few times, so i'm not real sure about it but it does seem a little sluggish and could do with a bit more grunt.
-possibly could do with a good tuning and the timing adjusted.
Anyway the fuel vapour is no longer there so I put it down to a bad gasket seal or hose connection -pretty sure the hoses were right though so suspecting gasket.