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Frame mounted Fuel pump vs in tank

K30Blazer

K30Blazer

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I believe my in tank fuel pump just crapped the bed. Kinda strange as both pump and sending unit are new as of a year ago. Walbro high pressure pump to keep up with the new LQ9.

Pump is not priming when turned on and I can hear the relays clicking over. Truck will turn over but not fire. Problem was intermittent at first leading me to believe it was wiring. I checked all the wiring, fuses, relays, swapped them around and problem went away. I never found anything that looked suspicious so I was kinda concerned it was going to come back. Well it did today.

Truck is stuck on side of the road waiting on my buddy to tow me home.

I checked with a multimeter and I have 12v running to and through pump all the way to the ground, so I am beginning to think this isn't electrical.

Pump won't prime or turn on at all.

I want to go to a frame mounted pump that I can put a tank pressure and evap sensor on anyway, any suggestions as what to start with?
 
You have to pull the pump out of the tank to install a frame mounted unit anyways. I'd just go with a new in-tank pump. They are quieter and tend to last longer than frame mounted pumps. They are also more efficient in their operation as pumps love to push fuel but don't do well drawing fuel up from tanks in external tank configurations. You also don't have to change your fuel system plumbing or wiring by going with a replacement in kind pump.
 
I guess I am just kinda skeptical as this one lasted only a year and was a walbro unit.
 
It appears that the 2000 Camaro sending unit might work. This would give me evap and gas tank pressure sensor hookup too.

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Stock TBI

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I read an article from wall to about Chinese knockoff pumps that are made to look the same but aren't. Might check around on how to tell if it's a genuine pump or not.

Could also be that the pump connector hose fell off inside the tank and the pump may still be ok.
 
It is not priming at all. I did run out of gas recently so I have heard that can destroy the pumps pretty quick.
 
Keep it in tank. Mine is external and is loud and gets hot.
I recently saw a redundant dual fuel pump setup you can switch back and forth with, both go in tank. Might be good peace of mind for you.
Also I'd take the time to cut a big door in your sheet metal so getting to the in tank pump is as easy as peeling back the carpet in the future.
 
ya, I am gonna cut the floor. Dropping the tank with the gauntlet bumper on would be a PITA. I just need to figure of the issue of the sending unit. If I could just drop in the camaro sending unit that would solve a lot of issues. I would love to have redundancy, but having access is the main issue. Cutting the floor just makes so much easier.
 
why not drop the tank and modify it for the correct fuel pump that has all the EVAP crap you need for smog?
 
like what? I have an LQ9 in it. I don't know of a pump that gives me the evap sensors on it that is designed for a K5 blazer tank. I think the Camaro is the closest
 
Just to be certain...you checked that the tank is grounded to the frame?

That would be great if that 2000 unit would work in place, I believe it was over at gearhead-efi I had seen someone adapt a later sending unit to an earlier tank, but it involved modifying the tank, which looked like a lot of work comparatively.

I assume the reason for EVAP/tank pressure is a later LS-series swap? Oops...took to long to respond, now I see LQ9. :)
 
hmm, a lot cheaper than the camaro pump. Is it deep enough to catch the bottom of the tank? Can't get a view on it
 
My local parts store has a stock sending unit and a Tahoe pump in stock. Gonna go down and compare them.
 
If you go this route make sure you buy a quality pump. I figured you would but I had a bad experience with an autozone pump, maybe got 15k miles out of it before it died. Went with an AC Delco the second time and it's been fine.
 
So I measured the Tahoe pump at Oreillys and it is 9.75 tall and 4 inches wide. Like like it would be a perfect fit. Gonna measure my tank depth tomorrow but that sounds about right.
 
Just measured my tank and it is 12 inches. Looks like I am going to need to pull my pump and sending unit and head over to the parts store to see what they have close
 
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