ZenkiDK

Hello Everyone,

Decided to post after trying to diagnose this problem for the last month. Car was running fine and one day this started to happen.

Mods:
Walbro 255
P2M 720cc injectors
2871r
Z32 MAF
RS Enthalpy Tune
all supporting mods

The Issue/Symptoms:
1. Car floods overnight. In order for me to get it started, I have to remove the fuel pump fuse, crank it to clear fuel, get it started, then put the fuse back in. At this point it runs fine. If I don't do this, the car just cranks and cranks. This is dependent on ambient temperature, not engine temperature.
2. Oil smells like gasoline and is beyond the 'H' mark.
3. Car breaks up at WOT, heavy fuel consumption, and strong fuel odor.

What I have checked/replaced:
Spark - Good + new spark plugs
Injectors - No leaks, O-rings look good
FPR - I originally thought this was the problem, replaced it with an OEM one, but problem still persists.
Return line - Not clogged
Fuel Filter - Replaced
Fuel Pressure - When car is on, 37psi and 43psi with vacuum disconnected.

Fuel Pressure Readings:
Last night, I primed the car and got the following readings:
1st attempt with key on: 20psi; stays at 20psi when pump stops
2nd attempt with key on: 43psi; drops to 30psi when pump stops
Today:
1st attempt with key on: 43psi; drops to 30psi when pump stops
2nd attempt with key on: 43psi; drops to 33psi when pump stops


Appreciate the help.

Thank You

6/1/2021 -

After further diagnosing, I've realized that the cold start issue is actually related to the ambient temperature and not the actual engine temperature. If the car sits overnight and its 40 degrees, it will not start. If it sits and its around 70 degrees, it will start.

Also, I am having misfires at WOT, a heavy fuel consumption, and a strong fuel odor.

No Check engine lights

I've replaced the Coolant Temp Sensor and have checked the main harness.

The Orange (signal start) wire on my ecu is showing aound 9v when cranking.

5/10/2020 -

Today I noticed that when I primed the car, it was able to maintain 37psi after I turned it off. Yesterday it would immediately drop down to 30psi.

Also, after managing to get the car started, it eventually maintains its AFR in the high 14s at idle. However, since my AFR gauge is connected to my headlight switch, I was watching it when I turned the car off and it creeped down to 10.5. Seems like something is happening during this time which is flooding the car?