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Gas in the lower intake

buck531

buck531

New member
So I'm tearing down the motor in the blue car that has a massive knock above 2k. Oil is silverish and nasty looking. When I pulled the blower off I got a huge wiff of gas. There is actual gas in the LIM valley (under the s/c). I can wipe my finger on it and it definitely is gas.

I'm guessing a leaky injector or possibly the FPR? But if it was either one of them wouldn't the cylinders get washed down and not the LIM? That and the injectors go into the head not the LIM. They're stock injectors, stock fuel rail.

Pic for reference as to what I'm talking about. The inside was actually super wet with gas.

1462401878941_zpsxiunrx1s.jpg
 


The EVAP system is designed to capture fuel fumes from the tank and route them into the intake. Overfilling the tank can saturate the charcoal filter and allow gas into the intake. There is an EVAP control valve that is opened by the PCM at specific times to allow fumes into the intake, it's one of those doodads that sits on top of the engine with both wires and vacuum lines going to it. I would bet that's where the fuel is coming from. The only way for it to get from the rail/injectors into the intake like that is back through the intake valves in the cylinders. If an intake valve is not closing and allowing fuel back into the LIM, then that would mean there is no compression in that cylinder either.
 
yeah I know what the evap does but it doesn't exist on the car. I took it off when I put everything back. That and every other emissions piece on it is gone. I'm just wondering if the gas got into the oil and thinned it out too much or was it the KR that killed it.

I know the compression is ok.. or at least it was before I tanked it. I'm going to pull the heads and pan off tonight to see what the damage is.
 
That's all I got.....how else would gas get in the LIM? Bad injector dumps gas in the oil and it comes back thru the PCV?

I just had my LIM off and it was coated with oil inside, like the PO never changed the PCV....ever.
 
I just put this motor back together less than 1000 miles and less than a year ago. Spun a bearing at the track on Friday. Yeah I'm not sure how else gas would get in there other than a leaky injector. I now when I pulled the vac lines off on the FPR it was bone dry. Generally when a FPR goes bad it starts leaking gas in the lines.

Just trying to figure out what spun the bearing.
 
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