If there's one thing we can't stand, it's when our cars suffer from low fuel pressure issues. So much can go wrong when your ride isn't receiving the amount of petrol the cylinders needed to put the competition in your rearview mirror. Not only does this sacrifice power and performance, but the damages that running a lean condition can cause could be detrimental. Enter our 2002 Trans Am WS6. This one-owner ride hales from the frozen tundra of the Midwest, and when the opportunity presented itself for its owner to relocate it to the "year-round summer climate," it was a no-brainer.
We have yet to formally introduce this F-body as a full-blown project car – but in due time, we will. Until then, we'll just have to sort out the issues it's currently suffering from before we can even get any baseline numbers for this thing. This T/A has had a ton of tech thrown at it in the past, least of which is an aftermarket fuel pump.
Unfortunately, this car has led a pretty tough life up to this point, and there were tons of mistakes made along from a previous build in the way of a shoestring budget, miscalculations, and poor judgment. It ran so poorly, that we couldn't even get a baseline to show you what kind of power this thing is putting to the wheels prior to the installation of this fuel system. So we went straight to the source of the problem, and immediately tore into it.
After we dropped the car off to Greg Lovell at AntiVenom Performance, he and Kyle Miller took on the task at hand. Prior to tearing the car apart, however, we discovered that the fuel pressure was a miserably low 36-psi, and since we sent the injectors out for a full cleaning and put in a new fuel filter prior to this installation, we knew that a clogged injector or filter wasn't the culprit. As it turned out, it was actually the previously installed aftermarket fuel pump, and the lack of proper voltage getting to the pump. Follow along as we show you the steps we took to bring our Trans Am's fuel system up to snuff.
1 Here is everything Racetronix sent over; the complete F99 package (PN: RX-F99-FPKG-2) that includes a brand new sending unit, housing, Walbro pump, 30-micron filter sock, a proper length no-kink factory-type flex tube (everything comes fully assembled), the hotwire harness, and even a few stickers and a T-shirt. Since Jack Levinson, owner of Racetronix, heard about our particular situation, he suggested that a completely new sending unit would be the only way to quell our low fuel pressure woes, since someone had cut a huge hole in our old one to make way for the universal pump that we had. We obliged, and followed his suggestion. Remember, the ‘98 LS1 F-bodies used a steel fuel tank, so this isn’t the exact kit you would order for a ‘98 car. This one only applies to the ‘99-02 LS1-equipped Camaros and Firebirds.
2 Of course, in order to replace the fuel pump sending unit, we had to disconnect the exhaust system, unbolt the Panhard bar, and drop the fuel tank. Many F-body owners suggest cutting a hole in the trunk’s floorpan, in order to have an easier access to the pump in the event that it ever fails again, or to install an upgraded pump as mods progress. Since your author isn’t too keen on “cutting up cars,” we chose to forgo that option this time around. Kyle is shown doing the work.
3 With the tank out of the car and on the shop floor, we pulled out the old sending unit, and prepared for the installation of the Racetronix unit. Truth be told, the Racetronix-supplied unit is actually an OEM piece, but with the Walbro pump installed for you. In the bottom photo, you can see that the original sending unit had an additional hole cut into the bottom of it, to make room for the larger, “universal” pump that was previously installed.
4 Kyle prepares the installation by installing the Racetronix-supplied seal for our sending unit. This seals the sending unit to the tank, and keeps unwanted debris and moisture out of our fuel system.
5 Next up was sliding in the pump/sending unit, and connecting all of the fuel lines into the sending unit. The lines are pretty self-explanatory, with the routing set from The General. All you have to do is match them up with the tubes attached to the top of the sending unit, and clip them in place.
6 With the sending unit in place, we turned our attention to the hotwire kit Racetronix sent to us. What’s the point of this? Well there are a ton of benefits to this harness, including the fact that our Walbro fuel pump requires twice as much power as a factory fuel pump. As Jack tells us, the factory wiring is just adequate enough to power the OEM pump, while the Racetronix harness is up to the task at hand for our high-performance pump. It offers better insulation to keep the wiring out of the elements, and a direct feed from the alternation to the pump, to guarantee that your high-performance pump gets the voltage that it needs.
7 Kyle routes harness from rear of Trans Am to front. You connect the “redundant” ground supply upgrade that clips into edge of gas tank, while routing harness over rear axle and along undercarriage.
8 As you can see in this photo, we attached the connector for the hotwire harness to the plastic tab the General Motors was generous enough to supply us with from the factory. Not pictured, is the hotwire harness ground wire that attaches to the alternator, by simply removing the bolt that holds the factory alternator ground in place, and sliding the Racetronix wire in over the bolt attached to the alternator, and retightening the nut.
9 Before we could test drive the car, all we had to do was reinstall the fuel tank, reconnect the Panhard bar, attach our exhaust system, and connect the battery. Needless to say, the new pump kit helped our Trans Am out, and the car is at least drivable again. We checked the fuel pressure after we got it running, and it was right at 58 psi, where it should be. The Trans Am still could use a tune, however, and we’ll be looking at handling that in a future issue of GMHTP.