Fuel in the intake manifold

Is it for sure fuel, aka gasoline. Might be due to PCV (Positive Crankcase Ventilation) vapours introduced to the intake manifold, depositing a mix of oil/water, with just enough gas to give it a sharp smell?

 

So on your vehicle you don't have the bladder in the tank and the changeable electric fuel pump and so on is this correct It's the same as the UK edition If so that's a bonus for you you can play around with the fuel pump and pressures and just about anything you want to because you can actually get to the fuel pump to the bottom of the back seat here in the United States and federal vehicles you can access that there's a bladder in the tank like what's in a bladder type water tank for a well pump system It's really kind of silly.

 

Take the intake manifold off and clean, say with brake cleaner, rags and brushes?

If it's gas, how would it get into the intake manifold? Not a rhetorical question, but it is a puzzle. The injectors are in the intake ports, aimed at the valve openings; could that spray be back splashing somehow?

Taking off the intake manifold will also allow you to clean off the injector tips, and the intake ports, might shed some light.

Gen 3 PCV is very prone to dump gunk, due to it's position on the sidewall. I keep forgetting Gen 2's PCV valve is on the valve cover. Still, PCV is a common culprit.

Also, with the intake manifold off, see if you can collect some of the stuff, get it into a narrow jar and let it settle, see if it separates into layers.

 

^ Attachment says "non-reusable" on the intake manifold gaskets. Your call, if they're in good shape you can get away with reusing, still, gen 2, and never been off, safer to replace. They don't cost much. If you do replace them, then have it off soon after, just to recheck, I'd have no qualms about continuing to use the new ones.

 

Doesn't the Atkinson cycle ICE release some of the fuel/air compression cycle back into the intake manifold? I recall the floor of my GEN II intake manifold had a fairly regular fuel/oil mixture about an eighth of an inch deep.

 

I would get a scantool and look at data from the ECM. Specifically Short Term and Long Term Fuel Trim. These are corrections that the ECM makes to fuel injection amounts based on the Air Fuel sensor in the exhaust manifold.

If everything is "like it left the factory", Fuel Trims stay near 0%. If the A/F sensor reports a "lean" mixture, STFT makes a positive (+)% correction. If STFT stays away from 0 long enough, LTFT will make a correction and STFT should return to 0. (ST and LT trims are added together for "total" fuel trim). STFT is a temporary reaction to the A/F sensor. LTFT is a learned response to STFT. There are different LTFT "cells" for different combinations of RPM and load. So fuel trims at idle can be different vs. acceleration vs. highway cruise.

The same is true "in reverse" - if A/F reports a "rich" mixture, FT make a negative (-)% correction.

I mention this because one of the only ways to have "excess" gasoline in the intake manifold would be for the fuel injectors to be leaking (dripping) or otherwise faulty. That would affect combustion while the ICE is running, and would show up as negative fuel trim values.

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