fst100

so i let my car sit for 3-4 months and it has a e47 blend fuel. in january i rememberd to pour 2oz of stabil in the tank to help the fuel from breaking down. fast forward to this past saturday i was able to fire the car over and let it idle for about 5 minutes with periodic brake torque to 2k RPMs. today i went and fired it up and it idled as normal and after 5 minutes i noticed the motor started to stumble and it stalled. i turned it over again and now it just barely idles. the fuel pressure on the RPD shows 72. no matter how much throttle i apply on the pedal, nothing happens.

i connected my obd2 dongle and checked for codes on my torque app and no pending codes. again if i apply throttle, the TPS doesnt move at all and stays at 14%. i turned the motor off and key back to accel on but not to ignition and the fuel pressure gradually goes up starting at like 300 then slowly climbs. if i start the motor, the built fuel pressure then drops back to 72. car has 170k miles and i only got the car at 150k. any insight is greatly appreciated.

Oldblue

Stale fuel comes to mind! Condensation in the fuel also!

fst100

thats my first thought. it has half a tank and i just poured only 2 gallons of 93oct (only got 2gal jug). dunno how long i should let the motor idle? it just sounds horrible idling around 300-400 :-(

firemangeorge

You mention the RPD so I'll assume you're talking about a SS.
A lot of your "facts" in your post don't make any sense. You can't have a high pressure reading of 300 unless the engine is running (the high pressure fuel pump is a mechanical, cam driven pump. The engine must be running for that pump to work)
If you are getting a reading of only 72 psi with the car running, that is the electrical tank pump pressure only. The high pressure mechanical pump is evidently not working.

donbrew

E47 sucks water out of the air, StaBil won't help that.

fst100

yes, its a 2010 ss. i'm only stating what i see. can take a video to show that it apparently climbs in pressure on the RPD. so the fuel pressure thats on the RPD is showing pressure in the tank then correct?

firemangeorge

No. The reading on the RPD is either from the high pressure fuel pump or at the fuel rail. That low reading (72) you see is pressure from the in tank pump, pumping through the fuel line to the high pressure pump (HPFP) Remember that the SS has 2 fuel pumps. In tank electrical supply pump and a mechanical cam driven pump on the end of the engine valve cover.
On my 2010 SS, I see about 2200 at cold start idle on the RPD. Drops down to 400-600 range after warm up. The SS engine has direct injection (DI) and must have the high pressures for the DI system to function properly.

fst100

ah ok, didnt know the ss has 2 fuel pumps. with 2 fuel pumps, whats the best way to tell which one is possibly faulty, by process of elimination? i was thinking fuel pressure gauge that would be on the fuel rail but that would see pressure after both fuel pumps?

fst100

so i just went out to capture a short clip and upon starting the car, the fuel pressure now reads above 1k when idling? i'm stumped. after shutting down and turned the key to acces on but not crank, the fuel rpessure held around 1000-1100
here's the link to the video:

Oldblue

Moisture in the fuel.