oil mixed with gasoline, issue during break in

Mxspeed3XX9

Gold Member
2008 MS3 — stock. Engine rebuilt 3 months ago.

I rescued this car from a friend: it came with no engine installed and
everything piled in the trunk and on the seats.

Issue: the PCM is not grounding the low-pressure (in-tank) fuel pump, so
with key on / engine off the pump doesn't prime. If I jump the relay
circuit to ground, the pump primes and the car starts.

Once it fired up, I started the break-in to check for leaks, temperature,
fuel pressure, etc. It ran for about 10 minutes with rpm varying between
1000 and 2000. After those 10 minutes I let off the throttle and the
engine shut down. It cranks but won't restart.

It seems to be running rich — logs attached, both from the shutdown and
from the first restart attempt (crank, no start).

Looking things over, I found the valve cover crankcase ventilation hose
was disconnected (my bad). The oil smelled strongly of gasoline, so since
this was the first start anyway, I changed the oil and the filter.

Spark plugs are all brand new (NGK, 0.8 mm gap) and only cylinder 1 came
out with carbon on it.

I think the oil was heavily fuel-diluted.

My questions:

1. Can the disconnected vent hose make the engine run rich?

2. Where can fuel be getting into the oil? HPFP, leak injector , How to check before start again?

3. On the PCM issue: I traced the circuit from the H1 pin to the relay
and I have continuity. All grounds check out — under the battery tray,
at the HPFP, the two behind the headlight, the two near the clutch
slave cylinder, one under the power steering reservoir, and one near
the passenger-side engine mount. What else should I check before I
condemn the PCM?

thank you.
 

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