why everyone should rewire their fuel pump
For anybody that has not done this, what the hell are you thinking, just do it, it is a very simple fix and you get the peace of mind that you will not damage something at wot.
Joined: Mar 2001
Posts: 30,804
Likes: 646
From: FL-->NJ/NYC again!
Definitely be careful with the grommets going through the pump carrier, I've seen an instance of fuel wicking up the wiring into the back hatch area......
Joined: Sep 2004
Posts: 3,258
Likes: 9
From: South Florida
You can run an extra relay or jump the wires in the front fuse box like Dale Clark wrote about. Only problem with the later is if you have a problem in the harness somewhere up front, it will still persist in back.
I just de-pinned and re-attached my own wiring to the factory bulkhead.
It should also be noted that your fuel maps will be running richer in all areas now. My cruise map went a full point richer, I don't recall what the boost areas were because I just retuned everything.
Joined: Sep 2004
Posts: 3,258
Likes: 9
From: South Florida
my idle fuel pressure went up about one psi so i assume that the pump is now getting the required voltage thought the powerband and not just at idle

hey Rich, do you know if you can purchase replacement electrical plugs for the connections on top of the fuel pump cover, or do you need to buy the whole harness?
Joined: Sep 2004
Posts: 3,258
Likes: 9
From: South Florida
problem with the resistor bypass is that you are still using the long and dry car wires. You only gain that you are full voltage all the time but at WOT or where the higher fuel consumption is necessary, you won't gain anything from this since the stock relay is already triggered.
So it is a pretty useless mod. You better rewire it completly with a new relay and a new wire directly from the battery.
So it is a pretty useless mod. You better rewire it completly with a new relay and a new wire directly from the battery.
You mean he bypassed the stock relay in the box in the very front of the car? Just leave it like that, you can still install a new relay in the trunk with a new wire to get the better voltage.
Do this mod now!
I re-wired my fuel pump and my car ran so incredibly rich I had to pull TONS of fuel out on the dyno. The car stumbled and fouled the plugs just by rewiring the fuel pump on STOCK injectors and STOCK fuel map on PFS PMC.
I ended up being able to run 16psi on the dyno making 330RWHP up to 7500rpm with a 10afr out of rewiring the pump. I would never run this on the street of course at 100% duty cycle but the point is, DON"T mod anything on your car until this is done.
Hell, this is a mistake, pumps should be directly wired from the factory. Think of all the possibilites and hassles of having inconsistent fuel pump voltage....this is probably a hidden cause of many engine failures...people thought their base map was enough fuel, but the pump wasn't getting enough volts.
I ended up being able to run 16psi on the dyno making 330RWHP up to 7500rpm with a 10afr out of rewiring the pump. I would never run this on the street of course at 100% duty cycle but the point is, DON"T mod anything on your car until this is done.
Hell, this is a mistake, pumps should be directly wired from the factory. Think of all the possibilites and hassles of having inconsistent fuel pump voltage....this is probably a hidden cause of many engine failures...people thought their base map was enough fuel, but the pump wasn't getting enough volts.
problem with the resistor bypass is that you are still using the long and dry car wires. You only gain that you are full voltage all the time but at WOT or where the higher fuel consumption is necessary, you won't gain anything from this since the stock relay is already triggered.
So it is a pretty useless mod. You better rewire it completly with a new relay and a new wire directly from the battery.
So it is a pretty useless mod. You better rewire it completly with a new relay and a new wire directly from the battery.
The resistor bypass alone won't help much. I like to get rid of it mainly to simplify the system and eliminate a possible failure point. I got a full extra volt at the fuel pump by running a direct fused 12v wire from the battery to trigger the fp relay.






