What's new
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

Tbi Pump and sender in carb mech tank?

ProJunkRacing

ProJunkRacing

1/2 ton status
Joined
Jun 20, 2005
Posts
1,229
Reaction score
0
Location
FrankFort IL
will a tbi pump and sending unit work in a carb chevy blazer tank that was orginally mechanical pump just sender? i need to know if anybody runs this or has thanks . the hole looks similar in size but has anybody done it ?
 
all the ones before 87 ive pulled so far have ben large sender hole size

and ive always wanted to know if all the tanks were same 86 older and/or 87 up,

or 85 v-6 TBI and up

i know a bunch of ppl on here know the answer

so lets hear it

thanks
 
All the holes are the same.

Difference is in the baffles used in the '87-91 tanks for injection, and the depth of the tanks which changed how "tall" the sending unit is.
 
so whats that all mean ?

are screwed if put tbi unit in carb tank or carb unit in tbi tank ?

no way to make it work ? change float arm length or bend/angle ?

no ?

hmm
 
Say you've got an '81 K5 w/31 gallon tank. You want to install TBI sender out of 31 gallon 1991 K5 tank. It will work with no problems.

The "problem" is just that the TBI tanks all came baffled. If you get towards empty and get the truck on an incline, if the fuel pickup doesn't see any fuel, the engine will stall pretty much instantaneously.

Baffled tanks use a well that captures fuel on flat ground, so when you are at an angle, you have the pickup submerged until that well goes dry.

Stock baffled tanks are oftentimes junk by now, it's pretty typical (at least on donor trucks) that the plastic baffles are broken, which means they are at that point no better than a non-baffled tank, plus you have to remove all the pieces or the sender gets beat up. It appears a small impact with a fair amount of gas is typically enough to break the baffles off the mounting studs, and they aren't really repairable.

Aftermarket baffled tanks are right around $130, not bad for a brand new all steel design.
 
so can i make it work with a tbi pump my tank is a carb tank thats all i need to know what to do to make it work?>
 
Yes, as long as tank depth (capacity) is the same, any sending unit will fit in any tank. (within what we are talking about of course)
 
A shallow K5/Suburban tank (9" ~23 gallons) seems to take the same sender or sender/pump as a pickup truck. The deeper K5/Suburban tanks (11" ~34 gallons) take a longer sender/pump. They all have the same size hole for the sender to go in (and is the same on S10s, IFS fullsizes, et cetera... no idea on length) and use the same lock ring but some use an O-ring and others use a gasket.

The tanks changed over the years, mostly in the form of the filler neck vent. Some go all the way to the tank, others go into the side of the filler neck.

In 87, with fuel injection, they got a small cup on the bottom of the tank to use as a sump. In my experience, these little guys do just as good of a job of keeping fuel out as keeping it in. Some vehicles, especially IFS chevys with the 33 gallon tank, seemed to have gotten actual metal baffles in them to prevent fuel slosh. These usually break off and ruin the sender.



My wheeling rig has a carbureted 1979 K5 34 gallon fuel tank in it with an 1987C10 (20 gallon tank) sender in it. The pickup is a solid 2" from the bottom of the tank.
 
You could do it, but you'd be MUCH better off selling a working TBI sending unit to someone that wants it, and getting a carbed sender.

The fuel pump ends up being part of the pickup tube for the fuel, without a pump in place, you'd need to lengthen that line to the bottom of the tank, (steel line in carbed senders) then deal with trying to somehow filter that line.

I really don't know how easy it would be to pull fuel through one of the stock pumps, it certainlt can't help fuel flow, even if it is possible.
 
You must log in or register to reply here.

Latest Posts

Top Bottom