Fuel Pump Hot Wired; Bye Bye Knock!

[Rom3BreaK]

I just got done hot wiring my stock fuel pump today, and my engine knocking is finally gone! I'm really psyched.

Original Symptoms:

-My logger saw my fuel trims as Low: ~82(idle) ~90(driving), Mid: 110, High: Just under 120.
-Occasional sputtering/hesitation under load
-knock spiking to 20 counts now and again under load

First: I checked for intake leaks despite the fuel trims looking like the opposite of a leak condition. No change.

Second: New fuel pressure regulator:
-Trims were fixed! Low remained the same, mid: ~108, High: 102.
-Knock still remained, hesitation still remained.

Third: I did the hot wire with the help of a friend, drove it around for about a half hour and got nothing more than a rare 1 count of knock. Problem solved! Throttle response seems faster now and the ride is overall smoother with no more hesitation.
Fuel trims are now
low: same as original at 82 but now does not fluctuate higher while driving, Mid: 96, High: 105


I'm now contemplating re-installing the EGR system because I believe I heard this may raise and keep level my low fuel trim.

Man, I can't wait to turn my boost up! I don't even remember what stock boost feels like. The car already seems quick and the boost is only at waste gate pressure.

[Jimvr4]

Good to hear! I've been having a similar problem that I first noticed when logging a dyno session. If you don't mind, check out my logs posted in the Spyder on the Dyno thread and let me know what you think.

[Jimvr4]

I'm now contemplating re-installing the EGR system because I believe I heard this may raise and keep level my low fuel trim.

Found this reference which may shed more light.

http://www.stealth316.com/misc/obdii_fuel_trim.pdf

[mh3kgt]

I plan to hotwire my pump hopefully this weekend if weather prevails, I've got a bunch of rewiring to do since I keep draining batteries somehow and hotwire is on the list. Hopefully it will quell my random knock issue as well.