Mechanical fuel pump to feed electric pump?

[Mr.Jimmy]

Hey geys, I'm tossing a few ideas around about a tbi swap. Want to know what you guys think about putting my electric fuel pump after my mech. pump to sorta "prime it", that way I could mount the electric pump high in the engine compartment. I read about this in a thread a while back, did a few searches, but no luck. Do you guys think mech. pump would restrict flow to elec. pump? Any thoughts?

 

[Thunder]

I dont think it will work. Mechanical pumps dont have enough volume to keep a TBI pump fed. If there is any restriction whatsoever the electric TBI pump will fail. They are not designed to pull. They just push. Thats why they are usually mounted in the frame rail or in a location lower or at the bottom of the tank.
Seems like needless complication to me. Just more thing to break or have problems with.

 

[dyeager535]

It wouldn't work. Mechanical pumps are driven by a lever, which means they pump in surges. You can't surge an EFI system, so you'd need to add another tank for the EFI pump to draw from.

Agreed, needless complication. Run a surge tank, run an in-tank electric, or mount it on the framerail. I don't believe even submerging the pump in water for short periods of time would hurt anything. (anyone else watch Mythbusters?)

 

[Mr.Jimmy]

I was hoping you guys would say something like "great idea" but I guess I need to hit the local junk yards for a gas tank out a tbi truck. I dont want the pump on the frame rail, so in-tank it is. Was trying to keep costs down cuz im bettin its gonna cost an extra 100 bucks for the dang tank. Well doing it right the first time will be cheaper than F***ing up 10 times!

 

[dyeager535]

Be careful with the stock tanks. If you find one, pull the sender out before purchase to make sure the baffle isn't broken inside.

I *believe* you can use the 31 gallon tank/sender from a 'burb, but for some reason they have different part numbers. I'd want to find out why by physically comparing one to a K5 setup before buying.

The stock tanks aren't that good (because the baffles don't last) so personally I wouldn't pay more than $50 for a bare tank, but the sender IS worth more. I don't think you can buy those aftermarket for less than $100.

 

[Mr.Jimmy]

That sucks, I got my tbi setup from an 88 burb. I didn't think the tank would fit so I left it. If the stock tanks arent that great, what tanks are guys runnin? I wonna keep the tank under the truck, what are some tanks that fit? Your replies are appreciated.

 

[dyeager535]

There are aftermarket tanks made that replace the stock ones. Welded in steel baffles.

There is a post in the garage not more than two weeks old where we were talking about this, and someone had found diesel tanks (IIRC) for $25. I posted where I had purchased my tank.

 

[Mr.Jimmy]

thanks bud. youre a great help! Ill do the homework from here.