A little history and add this story has a happy ending, about a year, start to finish. (pictures below) I went to a cruise one summer Sunday about 60 miles from home. It was a good day so the show was packed and there was no getting out early. I decided to get something to eat while things cleared. About 8:00 pm I'm humming along the 4-lane about 20 miles from home when I notice I'm sucking fumes. I get off for gas but didn't make it and finished up about a mile from a station that was open. Not to happy but call home for gas can and fuel delivery. First attempt to start, it spins but won't fire. Get more gas, (I`m thinking maybe vapour locked, and the small can is not enough to prime it)... tried 3 more times! No go and it's getting dark so we drag it to a nearby grocery store parking lot and check things under the lights. Find not one, but two fuses associated with the fuel system blown. Go get fuses, replace them, nothing doing. Now it's getting late and as much as I hate to, had to leave the car there until the next morning which was a holiday as it turns out and the weather is about to change - for the worse.

Can't sleep, we're there by 6:00 am with more tools and voltmeter. Basically no fuel pressure and nothing is making it go. So, as it's early on a holiday, we hook up tow strap and sneak it home 15 miles, the back way. Before we get there, major thunder storm unleashes and the back road mud is unbelievable. Now, this car has never seen mud, not as long as I've had it, and rain only once. Took four hours to clean it up before anything else was even considered.

Once I've decided the fuel pump has to come out, the job wasn't that bad. Off with the fuel door and the rubber tray, couple of connections and hoses, a dozen bolts and out the assembly comes. The pump looked OK but it was fried. Hot wired on the bench, it wouldn't even hum. Doing a resistance check was fruitless. A little distressing that the fuses hadn`t done their job. (For future reference, myth about running the tank low should be respected). There was no thought of stock system going back in as a fuel system upgrade was already part of the hot rod power plan. I wasn't as peeved about the losing the pump, as the trouble surrounding it and having to do the work at a time not of my choosing.

Summit sent Aeromotive EFI fuel pump, assorted Aeromotive AN fittings, #8 & #10 hose and 5 blocks of fuel cell foam. After syphoning the tank as much as possible, scooped and mopped the tank dry, then left it alone to air out for awhile. By time I started, you couldn`t even smell gas. Turns out, these tanks have an internal bladder and nylon tray where the stock pump sits. Other than that, nothing stops fuel sloshing side to side, which in this case, is quite a bit more than typical tanks being almost the whole width of the car.

I started by building bars into the tank to restrain the foam, leaving an area open for the stock fuel level sender on the OEM assembly plus a bracket for the pickup fitting. It took awhile and lots of frustration because you have to do all the work with one hand. There just isn't room to get two arms through the hole. It`s just big enough to see what you're doing with one arm down inside. I would have preferred a sump style pick-up at the bottom but,in the end, I decided I didn't want to deal with holes in the bladder below the flood line so I elected to route the pickup out through the top. (In fact the pump primed itself easily and normally stays primed so it works just fine). Still took time to get the nerve to drill a big hole in the tank for the bulkhead fitting at the top - the point of no return. Then, bend a riser tube from the pickup to the new outlet next to the tank access plate, now independent of the original assembly. For record, the one thing I learned from watching OCC (until I had enough) is the value of a step drill (being only bit they own!). It's by far the best way to drill sheet anything including plastic. I bought a gasket for the stock assembly and wasn't pleased with the price. I've since found some from a Vette warehouse at more reasonable prices. The cover plate is pretty thin and I'm going to do a back-up ring one of these days to keep it from bending and get rid of any barely detectable gas fume leaks.

The battery had already been relocated and the stock relief valve (at the back of the fuel rail) had already been replaced with an adjustable Aeromotive in the stock position. By the way, it doesn't hold back pressure like OEM and that isn't explained in the documentation anywhere. When I called Aeromotive they said that was normal for their unit and maybe they should mention it in their literature. Ya think? It works great but you need to run the fuel pump for a little longer than the ECU does (which is just a bump for couple of seconds) to build pressure, then the engine to fires right away. Fuel pressure gauge is also required to set the pressure. By all accounts, the fuel pressure spec on a 96 is to be kept in a pretty narrow range and I'd say that's true up to and including most bolt on mods.

The costs were adding up so for a fuel filter, I went economy (cheap) and put an Earls on the fuel pump inlet. Within a couple of miles, the fuel pump was howling like crazy. It was noiser than stock when I first put power to it but now it sounded like a jet under the back of the car. Called Aeromotive who quickly decerned the Earl filter was the likely culprit, (he'd heard it before!) Take it apart and you`ll find a screen the size of a dime and in no way related to the size of the housing. The good news maybe is that it clogged so fast that I didn't get very far and/or damage the pump in the process. Got the proper Aeromotive SS mesh inlet and paper outlet ones which are much longer and have some terrific flow and holding capacity, problem solved. As far as AN type fittings go, I much prefer Aeromotive, they go together nicer than Russel or Earls and I prefer them whenever possible.

Getting the console apart to put the over-ride switch where I wanted it is another story. But that done, I engage it before an engine start (for the extra pump run time) and anytime I want to get "on it". The switch powered a 40 amp relay wired in parallel with the original fuel pump power supply, to the positive side of the pump. On a 96, the OEM circuit is also powered as long as there is oil pressure to give you a limp home feature (according to the service manual) and in fact the pump does run a bit after the motor stops. What I also found is that, while the fuses don't blow with power from the OEM fuel pump supply, you can audibly hear the fuel pump pitch increase when the over-ride relay is pulled in. I could have wired the OEM to the relay as well but I wanted a back-up in case the relay had issues.Doesn't change the fuel pressure because the bypass on the fuel rail is controlling the back pressure. Top end could be quite a different matter if the pump then under-delivers because of a voltage drop.

I ran it that way a few months while I shifted my attention to other matters. However, in the mean time, Im thinking a reed type relay is subject to vibration and g-forces so I really wanted a solid state version. To that end, I had my eye on Aeromotive fuel pump controller. Long enough that it changed from the original red housing to the current black. It's not inexpensive and I wasn't expecting much of a performance increase so was in no hurray. This past summer I finally got it in the budget and had one shipped.

Where to mount it? After some debate I elected to keep it inside even though the car almost never sees the wet. I settled on the back corner of the luggage compartment where I can glance at the LEDs in the rear view and where it's easily adjusted. There`s sound mat under the carpet and the VATS antenna is back there so I jury rigged some standoffs which worked nicely. Be advised that the fiberglass construction in the trunk area is pretty thin. I think if I were doing it again, or if I have any problems over time, I`ll switch to hallow wall anchors that spread out behind drywall like spider legs.

Other than being all solid state, what wasn't apparent from the documentation is that the Aeromotive controller is a PWM (pulse width modulated) and you can essentially control the fuel pump speed to match engine requirements. Why would you want to? Big fuel pumps tend to generate more noise and add a lot of engine heat to the fuel system. Having it slow down at idle almost completely kills the noise and reduces heat into the gas tank. No more whine, even better than the stock. You can adjust the idle speed so that the bypass is just opening at engine idle while providing the required rail pressure. It then uses a tach input to ramp up fuel pressure speed until it's full speed at 3000 RPM (setpoint adjustable). Interestingly it doesn't have a power light but there is a tach signal LED and a full speed indicating LED and and over-ride LED. When you jump on the throttle from an idle, there doesn't appear to be any lag and the full speed light pops right up with the audible increase in pump speed.

The wiring in general is staight forward, a power, ground, ECU power (original fuel pump power) and a fuel pump over-ride (to ground). MSD provides the required tach signal but running the wire descretely and safely to the controller took time. From the driver`s seat, I wanted an indicating light next to the over-ride switch. The controller documentation provides no specs on the over-ride ground characteristics and none are available anywhere that I could find so, call Aeromotive. This time no satisfaction, the tech really didn't know anything other than it gets grounded. As this is a solid state controller I had correctly guess that the over-ride contact voltage to ground measures 5 volts. There is next to no current through the transistor base when you ground it so forget trying to run even an LED directly. I've eventually resolved the issue with a double pole, double throw switch to isolate the grounding operation from the indicating light. However, not before I tried using a diode to isolate an indicating LED. In the course of a few minutes, it would leak enough voltage to screw up the controller and cause it to stop altogther (ie voltage over 5 volts). Was a little disconcerting when it let me down by the side of the road, thinking the controller was fried. When it grounded and reset I got home and revised the grounding circuit so that problem seems to be resolved with the new switch. Trouble is cruising is done for another year but hopefully, so is this particular fix.

|UPDATED|12/20/2011 4:35:30 PM (AZT)|/UPDATED|

That's some serious fuelin there! Hard core stuff, for sure. Excellent write-up and info!!! Thanks for sharing that with C4VR.
Oh...and it ain't no myth about runnin these cars low on fuel...it WILL overheat the factory pumps, and they WILL fail. It ain't a matter of IF...it's a matter of WHEN....