Replaced side saddle tanks with rear cell

[HumbleChevyBuddy]

So, this past weekend I replaced my side saddle tanks with a rear mounted fuel cell. Now my truck won't start and I'm trying to figure out why. I moved the fuel pump (pictured below within the passenger side frame rail) closer to the new tank and I also moved the fuel filter back as well. Even with this it's still not starting. Is the fuel pump still too far from the fuel cell? Does anyone have a similar setup or can anyone give me some advice? Please keep in mind that the wiring and the plumbing is still not final...I'm just trying to get it all working first, then I can run everything correctly. I also included a pic from the rear so you all can see how I have the fuel cell line running from the fuel cell itself.

Thanks guys!

[bigblock73]

Generally, elec pumps need to sit below the fuel level, they are gravity fed and push better than pull...and also need to sit close to the fuel source...yours looks like it is too high and too far away.

[HumbleChevyBuddy]

Originally Posted by bigblock73

Generally, elec pumps need to sit below the fuel level, they are gravity fed and push better than pull...and also need to sit close to the fuel source...yours looks like it is too high and too far away.

I'm sure I can move it closer to the fuel source, but I'm not so sure what I can do about it sitting below. If I put it lower than the fuel source, it's gonna be hitting the ground I understand what you mean, though...I just don't know what to do

[Pop's C-10]

I think tha distance may be you problem.

Here's how breeze85cten has his mounted

[HumbleChevyBuddy]

Originally Posted by Pop's C-10

I think tha distance may be you problem.

Here's how breeze85cten has his mounted

I can fix that this weekend. I'm confused on that pic, though. Does that have a fuel filter at the very back, then two fuel pumps?

[HumbleChevyBuddy]

Originally Posted by bigblock73

Generally, elec pumps need to sit below the fuel level, they are gravity fed and push better than pull...and also need to sit close to the fuel source...yours looks like it is too high and too far away.

I actually did my swap after seeing your article. How are you running yours? Or are you running the mechanical pump on the engine?

[russgt]

Did you try to prime the system?

[HumbleChevyBuddy]

Originally Posted by russgt

Did you try to prime the system?

Well, if by priming the system you mean getting fuel to the fuel pump, then yes. I removed the hose leading into the fuel pump, then I siphoned gas until it started coming out, connected it to the fuel pump, and tried to get it going still with no luck. I hope that's what you're talking about, otherwise can you please tell me what I'm suppose to do because I feel like an idiot now.

[silvereagle07]

Originally Posted by HumbleChevyBuddy

I can fix that this weekend. I'm confused on that pic, though. Does that have a fuel filter at the very back, then two fuel pumps?

It looks like he has a filter before and after the pump.

[SS Delux]

Why noy try and put the fuel pump lower just to get the truck started to figure out if that is your problem ? Maybe mount it with some of the perforated strapping for plumbing in your house.

[78maliburat]

gravity will feed youre pump ..is the hose coming out of the tank going to in side of pump ..could be a bad pump ?

[bigblock73]

Originally Posted by HumbleChevyBuddy

I actually did my swap after seeing your article. How are you running yours? Or are you running the mechanical pump on the engine?

I am running a mech pump. Your line from the cell needs to run downhill to the inlet of the pump (doesn't have to be a steep drop, just a slight one). You should move the pump to the back behind the cell for it to work best IMO.

Id run a mech pump if I were you...simpler, quieter, and more discreet.

[bmchevy1979]

I am thinking pump also because I have seen several pumps that will run but don't pump fuel at all even when primed

[russgt]

Originally Posted by HumbleChevyBuddy

Well, if by priming the system you mean getting fuel to the fuel pump, then yes. I removed the hose leading into the fuel pump, then I siphoned gas until it started coming out, connected it to the fuel pump, and tried to get it going still with no luck. I hope that's what you're talking about, otherwise can you please tell me what I'm suppose to do because I feel like an idiot now.

You did exactly what I was thinking, maybe try removing the pump and doing some bench testing to see if it will pump in any position/condition.
Also, this may sound dumb, but how much fuel do you have in the cell? and are you sure the pickup isn't blocked?

[bigblock73]

Guys, it is highly unlikely the pump is bad. Read the directions that came with your pump. On Holley pumps for example, it clearly states the pump has to be lower than the tank and close to the fuel tank to work. You aren't doing either. These things DO NOT like to pull fuel, they are designed to push. Where your pump currently is is dang near at the mid point of the truck...it is almost pulling as far as it is going to try and push the fuel. Mock it up behind and slightly lower than the cell, see what happens..shorten the hose too, don't try and make it run thru 3 feet of line before it even gets to the pump.

[78 Big10 454]

I swapped out my single 16 gallon saddle tank for a larger rear-mount 26 gallon tank. The mechanical pump works perfectly. I'd stick with that.

[HumbleChevyBuddy]

Originally Posted by bigblock73

Guys, it is highly unlikely the pump is bad. Read the directions that came with your pump. On Holley pumps for example, it clearly states the pump has to be lower than the tank and close to the fuel tank to work. You aren't doing either. These things DO NOT like to pull fuel, they are designed to push. Where your pump currently is is dang near at the mid point of the truck...it is almost pulling as far as it is going to try and push the fuel. Mock it up behind and slightly lower than the cell, see what happens..shorten the hose too, don't try and make it run thru 3 feet of line before it even gets to the pump.

I completely understand what you're talking about, just wishful thinking that I didn't have to rerun my lines again.

Originally Posted by 78 Big10 454

I swapped out my single 16 gallon saddle tank for a larger rear-mount 26 gallon tank. The mechanical pump works perfectly. I'd stick with that.

I think as you and bigblock73 point out, I'm going to be installing a mechanical pump this weekend. I think the main thing to understand is that mechanical pumps are "pullers" while electric pumps are "pushers". That right there says it all, for the position and location of this particular fuel cell.

Thanks for all your help, guys. I greatly appreciate it!

[HumbleChevyBuddy]

Ok, so I just wanted to give a final update on this post. I replaced the rubber fuel lines with metal ones, added a new fuel filter, and I also replaced the electric fuel pump with a mechanical one (hard as hell to get to). Changing it to a mechanical fuel pump did the trick! I kept the in-line fuel gauge before the carb and I could see it fluctuate while the motor turned over. Then, finally after a few more key turns she fired right up and was showing around 6 psi.

Next I'm going to put some new shocks up front that I just got in from Summit, need to get my frame realigned, front-end alignment, and finally the inspection to be able to FINALLY get it on the road!

Thanks so much for all your help, as usual, guys!

[joe231]

[bigblock73]

Awesome, congrats!

[muddnutz]

awesome i was wanting to get rid of saddle tank also maybe one day

[DREAMER1]

Post some more info on your rear tank. Cost? Why did you pick that particular one? How about extras you had to purchase to make everything fit?

[HumbleChevyBuddy]

Originally Posted by DREAMER1

Post some more info on your rear tank. Cost? Why did you pick that particular one? How about extras you had to purchase to make everything fit?

This article gave the me idea of how to do it (I believe bigblock73 wrote it up, but not 100% sure):

http://www.73-87.com/7387garage/chas...ellinstall.htm

It helped me determine which fuel cell to purchase and what I needed. I still plan on getting a similar type filler neck, but I'll do that just before I decide on the bed floor I plan on putting in. I plan on leaving it like this until all my other items are complete on my to-do list, since I don't really carry anything back there right now anyway.

The following is what I purchased:

-Fuel Cell, Summit, SUM-290108 ($169.95)
-Fuel Cell Straps, Summit, SUM-290154 ($31.95)
-3/8" aluminum fuel lines and bent them to shape, Autozone
-3/8" rubber fuel line, Autozone
-5 packs of 4 O-type fuel clamps, Autozone
-mechanical fuel pump, Autozone
-5/16" barb to 5/16" NPT fitting (for mechanical fuel pump), Autozone
-clear glass fuel filter, Autozone
-8AN Flare cap from Jegs (Item # 555-110313)
-8AN Female to -6AN Male Reducer from Jegs (Item # 555-110222)
-6AN 90° Push-Loc Hose End from Jegs (Item # 555-110071)
-Miscellaneous grade 8 bolts, lock washers, washers, and nuts from Lowes

My Dad works at a machine shop so he made me 2 - 1" tall spacers which are 1/2" in diameter with 1/4" holes drilled down the center for the front of the fuel cell. I also had him make me 2 - 1/2" spacers with the same measurements for the rear of the fuel cell. I did this because my truck has a rake and this helped level the tank out.

In the article, they use some c-channel pieces of metal, but I actually just used the spare tire bracket and modified it a bit. Here are more pics of how I made it all fit:

I had to move the spare tire bracket from the lower part of the frame to the top part of the frame and moved it forward to make it all work right. I bought some grade 8 bolts, lock washers, and nuts to hold it all in place.



Here are the spacers my Dad made for me:
FRONT


REAR


I mounted my tank above the brackets. This was mainly due to the fact that I was worried about it being too low and it would hit something on the road or going up steep driveways. The other thing I did differently was moved some of the bed cross sills a bit to make things fit just right. This can obviously only be done on a stepside bed. Once I get closer to putting a bed floor in, I'll figure out if I'm going to need to fab up some more cross sills, but I doubt it. I may go with just a sheet of diamond plate and just rhino liner the whole bed, but still not sure about that one. If I decide to go with the wood bed kit, I will have to custom make it since the holes in the cross sills and frame will no longer line up. Still deciding on that. Finally, I did not have to do anything with the rear brake line bracket. After installing everything, I still have around 3/4" between the bracket/line and the fuel cell.

I hope this helps!