excessive unburned fuel after intake manifold pull
 

Hey all,

Having an issue with fuel in the exhaust (lots) after pulling the intake manifold. Took it off last week to change some of the deteriorating hosing underneath/behind and do a clean wrinkle-red respray.

Reassembled a couple of days ago and have been messing with it over the weekend to try and get it running right - but it's still pumping a heap of fuel straight into the exhaust system somewhere. White smoke out the back (this is indicative of water i know, but it stinks of fuel and for the amount that's going through I'd have thought there would be a drop in the coolant level), and when running there seems to be fuel dripping down from the exhaust manifold gaskets, and fuel is visibly seeping though the gasket on the exhaust flange of the turbo

No oil in water, no water in oil, have tried the following:

- C/O spark plugs in case one wasn't firing and was letting the fuel through, doesn't appear any better
- Checked the leads and pulled one at a time to check that the idle changed (seems to, although #3 when i pull the plug is definitely wet and smells of fuel)
- Disconnected the injector on #3 (the one i thought suspect) and ran to see if it reduced the amount of fuel getting through (appears to still be getting through)
- Disconnected all injectors and turned over to check that there wasn't a leak/damaged o-ring and fuel was by-passing (sounds to me like there is still a combustion every now and again.. maybe fuel [I]is [/I]getting through?)
- Disconnecting AFM, Idles rough as expected when removed and settles back into a steady idle again when reconnected

Car is a '00 GC8 wrx with a later ('03 i think) EJ207 in it and VF34, still with a top mounted coilpack and leads though. Pod filter but otherwise stock, no ecu flash that i'm aware of. Ran fine before the pull and marked everything so shouldn't be anything on backwards/unconnected. What could be causing such a massive over-fuel?

Bit of a project car so no hurry to get it going short term, but any pointers on what i should be targeting if i pull the manifold again? i wouldn't have thought a dodgy injector or seal could pump that much extra fuel through, but appears to me that's the issue so far - reasonably new to wrx's although i've had some other project cars, so not sure if there's any quirks with these engines yet

appreciate any help - cheers

One of the lower orings on one of your injectors is leaking.

Yeah? Ok thanks mate, I'll take a look at them later and replace - see if that fixes the issue


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[Solved]
 

For anyone else that finds this thread with a similar problem - issue was lower o-rings on the RHS injectors. Both had split at some point and drying them out/moving around while removing the mani must have done them in for good

Replaced with new o-rings and isolators and all good now (Kit ID# IRK718 for the yellow side-feeds), thanks for the pointer Rossco. On to the next..

Cheers
Jadyn

This may be my problem also.

Pulled the manifold last weekend to install silicone intake and have had troubles all week.

Rough idle. Sometimes drops to stall at start-up.

Unplugged MAF and it does what's expected-so that's fine.

When I change gear above 4000-4500rpm the car drops acceleration completely for a second an then continues. E.g when accessing freeway.

Can only use 9 of 18 psi

Seems to run fine above idle to 4000rpm tho, so this is where I have been keeping it.

Sound the same ?

If so I'm off to the shop for o-rings today..