In tank fuel pumps and gas fillers questions.

[Yellow Cheyenne]

I am planning to put a gas tank from a 87-91 suburban in my pickup. I may also sometime in the future install a TBI or TPI and would like to prepare now when it is easier. If I install the in-tank fuel pump, does it need any computer stuff to run it? I notice on newer vehicles that have FI, the fuel pump will run for a few seconds and then stop when the ignition switch is turned to the on position. Is this few seconds of run time determined by a computer or does the pump build up pressure and then shut itself down when the pressure gets to a certain level?

Also, the point that I am planning to install the fuel filler neck is only about 2-3" above the top of the tank and the fuel filler tube will be about 18" long. Is that enough of a drop to allow efficient fuel filling or will I be at the pump for 20 minutes trying to refill the tank?

Thanks in advance for any assistance.

[Hooter]

Just hook the fuel pump up to a power source only on when the key is on

[O'l Buck]

I don't know alot about the pumps, but I do know that they require oil pressure to keep running, and a relay runs the pump for a little while before the engine starts, and if it blows an ecm fuse, the pump won't run (I learned this working on my 87 chevy pickup) I don't know anyone who has tried to run these pumps without an ecm, but I would assume there is a way to bypass all the ecm crap and run it off the keyswitch, you may have to hook up more than one hotwire and or ground ( I'd find a good schematic), since the pump is triggered from more than one source.

[Huck]

BE CAREFUL!! In tank fuel pumps are made for electronic fuel injected vehicles. They are in the tank because pumps are more effective pushing fluid then pulling it. Example---some BMW's had two--one in the tank and one midstream.
BUTTTTTTTTTT, before you go and attempt to install a tank with an in-tank fuel pump, (If you are running a carb) got to make sure it is a low pressure (carb) fuel pump as a fuel injection pump will overpower your needle and float in any carb!!!! It will NOT work! Carbs require a max of about 6-8lbs of pressure while fuel injection will be 30-60lbs of pressure, Special fuel lines----fuel line connections to handle the pressure, etc. Don't want to see anyone have too hot a truck!! Huck

[Yellow Cheyenne]

I guess I should have given a little more detail on my plans. I am planning to run the larger lines that would be required to supply a FI setup. I figure that since I already have to run lines to the new tank position, I just as well use the larger lines now. If I do the TPI or TBI conversion, I would then aleady have the lines there. I had also planned to install a fuel pressure regulator and set it to 5-6 Lbs. I am presently running a Edelbrock 1406 carb. I liked the idea of an intank pump due to less chance of vapor lock, although I can't really say that I've experienced any problems with vapor lock. Again, if I install the pump now, it would be there if I updated to FI.

[slam33]

You don't want to run an FI supply system on a carb, even with a regulator. those pumps will fail if you pressure them down. The pump is on a computer relay also. It would be better to wait, get all the parts to do the injection system, then install it all at the same time.

[Yellow Cheyenne]

Ok, I guess I've been talked out of using the in tank FI unit. Should I run an electric pump that would be mounted near the tank or just use the stock mechanical one that I am presently using?

Thanks to all who have responded so far.

[Longhorn Man]

Myself, I'd run the mechanical one. The'll last forever, the electric ones won't.

[mikep]

Ive run an in tank FI pump before with a carburetor. Primary fuel presssure was 32 lbs . I had a 2 stage system with a 3 port Barry Grant regulator just before the carb and a 2 port holley regulator just before the nitrous solenoid and a return line to send all the unused gas back to the tank. Actual pressure at the carb and at the nitrous solenoid was 6 lbs. I ran that setup for two years and never had a problem with it. All the lines were 3/8" steel with braided steel hoses.