I remember hearing for years that running an EFI tank LOW was the killer of fuel pumps. The rationale was that fuel cooled the pump, and that running the tank low caused the pump to run hot, which shortened it's life. I don't see how filling the tank would shorten the life of a pump.
I don't either, but I figured I'd ask since it's the only thing I did differently right before it died on me.
Correct- FI pumps are typically internally cooled by the fuel flowing through them. For example if your pickup is somewhat blocked (and therefore your fuel flow), you might cause the pump to overheat. Make sure your pickup is clean and that it is not too close to the bottom of the tank. Should be no problem to "overfill" your tank, there are no EVAP systems on these cars However, as pointed out by others if your tank is not vented somehow then it might be "collapsing" the tank (i.e. pulling the bottom of the tank up just enough to restrict the fuel inlet). -Bob C. p.s. Back in the day I drilled a super-tiny hole in my stock gas cap, maybe 1/64" or something. At the time I could not find a vented cap. Theoretically I might have been spilling a drop of gas at WOT but if I was I never noticed. FI options were a lot more limited in 1991
Press and hold the accelerator pedal to the floor before key ON/RUN. This prevents the throttle body injector prime shot. (the pump will still prime the line pressure) Do this as a habit anytime you turn the key on and are not going to start the car. Think of it as you pressing the accelerator on a carbureted car and squirting fuel every time you turn the key to ON/RUN. If you were to turn the key on and off ten times while playing with the FiTech controller, you would be putting a large amount of fuel in the crankcase. Key ON/RUN but do not crank( engine OFF) Initial Setup Engine Setup Toggle to bottom PWM The default is 74.5 Press button to get to the settings. Change the value and then "exit" and make sure you press "Send to ECU" and back out to the "Dashboard" and select Dashboard, so you can see the numbers, then turn the key off and wait to the numbers clear, so you know it has written to the ECU. (I always do it, even if I select "Send to ECU", then I key on and go back and check that the value is written) 100 disables PWM 0 Shuts off fuel pump. If you go to "Go EFI Pro Tuning" (option 12) You have several PWM options that you can adjust. Before you do anything, just make sure the initial setting is 74.5 and see it the unit will manage the pump correctly. If you are having issues, post back.
Got off the phone with the shop that has the car now. Old fuel pump is TI Automotive (Walbro?) p/n F90000288. I've been on the phone with FiTech and Aeromotive today. FiTech tells me the pressure regulator in the throttle body should be fine with a 90 psi/340 lph pump. I called Aeromotive and asked them for the equivalent of the above Walbro number, they pointed me to 11542. I overnighted the shop one from Summit. Stay tuned for more
That F90000288 pump is PWM capable. TI obtained produced the Walbro pumps, and then replaced the Walbro name with TI on the pumps. Pumps are made in Michigan and Tennessee. (for anyone with a TI EFI tank and wondering)
In my case, I thought the one I had might not be PWM compatible because of what I saw halfway down the Tanks Inc page for the GPA pumps that fit my tank: https://www.tanksinc.com/index.cfm/...ct_id=227/category_id=-1/mode=prod/prd227.htm However, above a certain horsepower threshold, the GPA pumps DO support PWM: https://www.tanksinc.com/index.cfm/...ct_id=605/category_id=61/mode=prod/prd605.htm The FiTech guy said that Walbro pumps are wonderful, and that they don't like running with PWM. I don't know if that means ALL of them. I wasn't impressed with mine crapping out so quickly (PWM or not) and I've heard good things about Aeromotive longevity so I gave it a try.
The DCSS (what you have) is PWM capable, the "Gerator" pumps are not supposed to be run with PWM. Yes. The Aeromotive Stealth pumps are good units.
New fuel pump is in, got the car home. Guy at the shop said there was a bunch of rubber junk floating in the tank, presumable from the wrap or whatever that covered the old pump motor. That sounded weird to me since it should have been made with a material that withstands gasoline, but whatever, I didn't see it myself so I took his word for it. I checked the PWM feature, it is set to the default 74.5
Are there any rubber fuel lines within the tank? Most rubber fuel lines are NOT submersible. (You can get it but it's darned expensive) -Bob C.
Not sure. This is what was in there: https://www.tanksinc.com/index.cfm/...ct_id=605/category_id=61/mode=prod/prd605.htm And the pump motor was replaced with this: https://www.summitracing.com/parts/aei-11542 Ultimately, I didn't see exactly what was used to put it back together.
Okay - if all that came with the unit from Summit / Aeromotive, hopefully they know about the submersibility of their items. -Bob C.
The Walbro unit in that tank and the Aeromotive Stealth are E-0 thru E-85 rated, so neither should have been affected by submersion. Hard to say what or how the rubber ended up in the tank. But a sock should have prevented any of that from causing a pump failure. Parts have been failing on cars as long as the manufactures have put parts on cars, and aftermarket parts, after you put them on. (that's why they call them "replacement parts"...)
Everything seems to be working normally so far, knock on wood. The new pump is a lot quieter than the old one.
The hose originally included with my Aeromotive pump and subsequently the Tanks, Inc. pickup unit are a hard plastic (teflon?) not rubber.
Have had a Spectra tank and fuel injection system of some sort in my car for about 10 years. 1 year on a walbro 255 that was not enough pump. About 3 years with a Denso pump for a turbo Supra that suddenly puked and stranded me. The last 6 years on an Aeromotive 340, hopefully many more... I have always run a full return system with a regulator. Run the tank under 1/4 full on a hot day and it will run badly, assume hot and aerated fuel. The only problem with overfilling is it will usually drip/leak.
the topping off thing only affects new cars with there emissions bs. had the issue on my 07 silverado. if you push more fuel after the pumps kicks on them it can push fuel dirt ect threw the vent solenoid. you dont have that bs on a old buick.
