Low fuel pressure - 2015 1.4 - P2635 code

[Shawnigan]

Hello,

Car died 1900 km from home (ugh - I live in BC but am visiting Saskatchewan). I don't have a fuel pressure gauge but pressing the schrader valve pin resulted in a dribble, not a spray.

Is there anything besides the fuel pump that could affect (lower) the fuel pressure? There is no smell of fuel i.e. a leak in the system.

Also, when the pump primes and then shuts off (and I don't start the car), is the pump shut off triggered by the fuel pressure sensor sensing sufficient pressure or is the prime duration simply a timed event?

The car has 180,000 km on it. In June 2019, at 121k I replaced the OE fuel pump with a RockAuto "GM GENUINE MU2108" (cheap) one. In June of this year at 170k the replacement pump went. As the previous one was just two weeks past the warranty I spent more money and bought a RockAuto "DELPHI FG1741".

I thoroughly wiped the tank prior to pump installation but for all intents and purposes, there was no residue.

The two previous times the pump died, if I waited for 3-5 minutes, the pump would prime/run and get me a little closer to home. I only drove it home (less than 60km each time) and replaced it. This time, once the car died, it never did start again even though I could hear the pump prime. I only have a cheap OBD2 reader but the code is the P2635 and from Google: "... is a generic powertrain code related to computer output circuit issues. It means that the fuel pump 'A' is registering a low flow, or one not within the preset parameters."

Apologies for my wordiness - thank you in advance for any answers/suggestions.
Michael

 

[Simplyjesse]

This site is mostly dead bud. If you haven't found any answers try the cruzetalks forum. I'm no expert but I am pretty sure the fuel prime is a timed event. 2 pump replacements in that short amount of time sounds fishy, but it could have just been a bad pump the second time. After 2012 they had no fuel filter so I think the only other thing it could be is wiring, air lock, fuel line blockage, or ecu commanding it not to pump. Good luck, hope this helps.

 

[Shawnigan]

Thank you for your reply and I should have updated mine.

So the problem was me (okay a little of the pump). When I first installed the 2nd replacement, the gauge read zero fuel. I was sure the float had swung freely but... not 100%. I pulled it all apart again and gingerly reinstalled the unit making sure there was movement until I couldn't get my fingers in there any more. Filled it, turned the key. It hesitated a few seconds and then the gauge read fuel in the tank.

I've been told and have read, to try to never let your tank get below 1/4 as the pump can overheat when cornering hard and sloshing fuel to the side and away from the pump. I was diligent in not letting it get too far below a 1/2 tank between fills. When the car died, the gauge read 3/8 and when I did the math in my head (travel since last fill) it sounded about right - I forgot a couple of local trips. I pulled the tank after writing my first message, and it was almost bone dry. The minimal sloshing when I dropped the tank should have been a major clue but my head was elsewhere.

The float is now stuck on empty again so I'm going to have to do it all again but at least I'm home.

Thanks again.

 

[Simplyjesse]

Oh gotcha. Yah that will do it. Cool, glad you got it fixed. Cheers!