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50 miles into a 200 mile trip, my 2011 Panamera Turbo engine (133K miles) started to behave as though the plugs and coils were fouling. I got a yellow engine light on the rpm gauge and a red "reduced engine power" diagram on the display. The car was semi-OK under 2000 rpm's, so I was able to limp home. The codes thrown were P1021, P1023 & P12A1; all related to Fuel Pressure. While searching for a quick solution I heard what sounded like a fuel pressure release, about 20 minutes after the engine had been shut down. I believe it came from behind the bank 1 (USA drivers side) near the fire wall and when I stuck my hand back there I did get some reside fuel and also some oil.
This first picture is for reference. This picture is for reference. I heard a pressure release and smelled fuel. I placed my fingers in and around the hole and found gas/fuel. There was oil down the side of the silver device where it flattens out. You can see there is just a little bit still there, a day later.
I could see fuel (not oil) inside the hole for a few minutes. I have no idea where the oil came from. It definitely looked like engine oil to me. I searched as best I could without tearing into things, ...nothing.
All codes have something to do with Fuel Pressure. After several Forum searches, I convinced myself that maybe the plugs and coils decided to misbehaved (causing the fuel codes to pop), so I replaced them all since I had been putting "plug-maintenance" off for several months now (laziness). Replacement did not help at all; in fact, it caused another code to pop up, P1026, also related to Fuel Pressure. I guess I have a fuel pressure issue, ha, better yet, rats!
Does anyone know a simple way to diagnose/fix? I do smell fuel vapor when I start the engine, it runs really rough right now, after the plug & coil change. And it's hard to start, so I now believe it's a fuel issue. Nothing drips onto the garage floor. I was under the impression fuel pumps just die, not perform in low pressure.
The car has always run very well. Any suggestions?
I think it's a HP fuel pump problem. It's not normal that have fuel here.
You second picture i think is fuel regulator, i see spring. But there is membrane and it's possible that this membrane is hs.
Last edited by Marcus13190; 11-14-2023 at 12:09 PM.
I think it's a HP fuel pump problem. It's not normal that have fuel here.
You second picture i think is fuel regulator, i see spring. But there is membrane and it's possible that this membrane is hs.
I believe you are correct, car is in the shop getting the HP pump replaced.
Ask them to run diagnostics on both the high pressure pump and the low pressure (stepper) pump. Both can cause problems over time (long cranking upon start-up, sluggish running, and the "low power" error lights). Usually the error messages reset upon restart then come back later when the car is restarted after it sits for a period. Had exactly those symptoms and both pumps failed diagnostics. Replaced both pumps and the car has been fine ever since.
Ask them to run diagnostics on both the high pressure pump and the low pressure (stepper) pump. Both can cause problems over time (long cranking upon start-up, sluggish running, and the "low power" error lights). Usually the error messages reset upon restart then come back later when the car is restarted after it sits for a period. Had exactly those symptoms and both pumps failed diagnostics. Replaced both pumps and the car has been fine ever since.
I believe they have run the diagnosis you've mentioned; this what the repair quote stated: "Fuel supply from electric pumps to engine ok. Step-up pressure for direct injection too low, and related codes return shortly after clearing & running. Will require high pressure fuel pump replacement at least, then clear faults, run and monitor for any further issues with direct injection."
11-12-2023, 09:21 PM
Gen 1 970 Turbo Engine issue, expert help pls
