Quick rundown:
Vehicle was having issues taking off, i.e. acceleration problems. Receivd codes: P0171 and P0174. Replaced DISA valve, rubber boot, MAF sensor, still had issues. No vacuum leaks detected. Rented a fuel pressure tester, fuel pressure was zero. During the unscrewing of fuel pressure tester gauge, schrader valve broke. Decided to replace fuel rail once fixed. Replaced fuel pump with dismantler used pump, vehicle turned on great, no problems whatsoever. 2 weeks later, and about 2-300 miles, I replaced the fuel rail with a used one from ebay, as well as a MANN fuel filter. Vehicle ran great.
About 500 miles later, vehicle suddenly had issues with acceleration after coming to a stop at stop sign. Upallnight suggested that it probably wasn't a fuel related issue as the "cog" light lit up on dash, suggesting a tranny problem. Every time I turned the vehicle off and on again, the cog light would be off, wouldn't come back on unless I was having the acceleration issues which was every day. P0171 and P0174 came back. Replaced fuel pump with another used one, still had the issues. Was kept being told it is the fuel pump, even though I had replaced it yet again because pressure at schrader valve was sometimes 0 sometimes 20ish, 30ish at best. I purchased a cable and ran INPA and BMW Scanner 1.4 Nothing too bad, (except that fucking thermostat that I still haven't fixed because I'm waiting on fixing this fucking other dilema first), 31 errors from the LCM, possible issue, removed the glovebox and checked fuses, also under carpet where LCM was, no moisture or rust. Decided to replace the relays while I was at it.
Today I ran fuel pressure tests. First I connected the gauge to the fuel pump directly.
Pressure at fuel pump - YouTube
On this video the fuel pump is running fine, 50ish PSI, even when my brother steps on the gas and you can hear it struggling, the pressure doesn't fluctate.
On this video, the fuel gauge is on the fuel rail.
At fuel rail - YouTube
Fuel pressure is slowly going up, unfortunately the car then died (battery). But pressure never built up like at the fuel pump.
After the car charged for a bit, I pulled the bottom protective shield and connected the gauge to the fuel filter. Video 3:
Pressure at fuel filter - YouTube
Even with the car sputtering and not revving high, the pressure is maintained at +/- 50 psi. no fluctuation. Following bcredliner's advice, I tested to see the fuel pressure regulator function:
Quote:
To test fuel regulator verses the fuel pump--- attach the pressure test gauge,use above method to activate fuel pump with engine engine off. The residual fuel pressure should be 50.76 +- 2.9 PSI.
If pressure is low repeat test gradually pinching the return line. If pressure rises rapidly the fuel pump regulator is likely at fault. If the fuel pressure does not rise, fuel pump is most like at fault.
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I wasn't going to jump the vehicle but I did have the vehicle running when I pinched the line. Pressure was still the same on the fuel filter, but the vehicle actually ran fine (redlined and everything) with the line pinched. Without it pinched, the vehicle sputtered and felt like it was going to die. I had already ordered a Beck/Arnley fuel filter from Amazon that came damaged, and am awaiting a replacement by Wednesday (1 day shipping, fml).
UpAllnight still says it is the fuel pump, as he has been adamant that a used fuel pump is shit, and maybe he is right, but 3 fuel pumps in a row is far fetched, but not impossible.
FUCK IT. I'm ordering the 100 dollar ebay pump once and for all to just see if it will fucking work.
I'm sooooo agitated and tired of this issue, I just want my car fixed! FML.
