88 suburban fuel pump swap for future ls

[Arodsbowtie]

Hello everyone I have an 88 suburban that I'm trying to get running it has the original TBI motor. I want to put a LS in it but it's still drives only needs a fuel pump I was wondering about dropping the tank and putting a wallboro 255 pump in it and prepare it for the LS but still run the TBI for now I know there's pressure differences and I've read that the TBI unit has a built-in regulator so I was wondering if anybody has done that. I only want to drop the tank once to put the LS fuel pump in I just need a driving vehicle for a little bit before I do the ls swap thank you everybody in advance.

 

[Ricko1966]

I have not done a higher pressure pump on Tbi.Hell I haven't even seen a TBI motor in years. But we used to commonly run carbureators on injected cars that came with 35 psi pumps.The way we did it was run a tee in the main line straight side of the tee went to the carb the dog leg side of the tee went to the return line we put a restrictor in the return leg hose and just kept drilling it bigger until we had the pressure we wanted.I don't see why the same thing wouldn't work in your situation.

 

[Frankenchevy]

External return style regulators are available as well. I’d go that route so you don’t overpower the TBI regulator. TBI pumps are only about 12-15 psi max.

While it may work without a regulator, you may also end up with problems. The external regulator will make everything play nice and also won’t prematurely kill your new pump or TBI regulator.

 

[Bextreme04]

The walbro pumps have been getting a really bad name lately. I used to use them almost exclusively in aftermarket boosed fuel injection application but have seen a lot of people using them for swaps and having issues. I would just use a GM factory ep381 pump. It flows just as much or more as the walbro and is far more reliable. Also its a direct fit into the stock TBI sending unit. Runs about the same price or a little cheaper than the walbro too.
https://www.rockauto.com/en/moreinfo.php?pk=90717&cc=1303108&jsn=930

The specific LS motor you get will determine what the fuel system will look like after that. Some will have a return line system with the regulator built into the fuel rail. Others will have a returnless system that needs a regulated feed. Most people use a corvette filter/regulator or adjustable aftermarket regulator for those applications.

 

[Bextreme04]

Also, I would just wait and do it all at once. There isn't really any benefit to doing the pump now as it's only about an hour job to drop the tank, pull the sender, replace the pump, and reinstall everything. You'll have more time spent trying to put in a patch-job return line system and then have to redo it anyways when you get the LS in. Just swap everything at the same time.

 

[Ricko1966]

@Bextreme04 good points. I was assuming his tbi pump was dead and he just wanted to do the pump once, that's why was advising on the temporary cobble up. But if it runs absolutely, do it once do it right when swap your ls.

 

[Arodsbowtie]

Thank you everyone for your replies. I picked up the suburban through a friend for 500 dollars. I am already into a ls swap on a 85 gmc short bed. My buddy told me about it to get the seats front clip and doors. Then use anything else we could for the swb and we were gonna scrap the rest. Well as I got to looking at the suburban after we brought it back to the shop I realized this thing has remained untouched it's all factory fully loaded. It's straight and I'm thinking this thing would be pretty sweet with a 6.0 in it.
The only thing is I could really use another another running vehicle because my wife recently wrecked hers. I haven't seen this thing run but the guy said it only needed a fuel pump and it's just been sitting for a few years.
So I'm thinking if I can put a battery in it pour a little bit of fresh fuel in the throttle body see if it kicks off. If so I thought I'd just put the fuel pump in it and drive while I'm still building the swb.
I don't want to put a bunch of work in to getting the tbi to run. All my funds are tied up in the swb and finding a small reliable vehicle for the wife.
Any ideas on what a guy with too many project and not enough time or money to do them all?

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[Arodsbowtie]

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[Ricko1966]

Smack the bottom of the tank a few times with a big hammer if it doesn't pump.

 

[Camar068]

Run dedicated/new power to the pump...including the ground. Eliminates troubleshooting bad grounds or old wire in the future.

 

[skysurfer]

My tbi system has been running a Walbro pump and Aeromotive 13301 regulator for 10 years with zero issues. The pump, if I remember correctly, is rated at 180 lph. The reason I didn’t install a 255 lph pump was I was concerned the stock tbi return line couldn’t handle the excess fuel. The tbi system builds pressure by restriction, and having too much fuel pumped with inadequate return would cause pressure to rise regardless of what the regulator was doing. I don’t know what the fuel demands of an LS engine are, but installing the biggest pump available without some research could cause problems. The regulator I used came with a couple of different springs to handle higher pressure demands but the lightest spring was more than enough for a stock engine. My Aero regulator is mounted in the return line (on the frame by the fuel filter) downstream from the factory regulator. With the Aero’s higher set point causing more line restriction, the factory regulator senses the increase and goes wide open in an attempt to reduce pressure. As such, there was no need to modify the factory tbi regulator at all.

With regards to Walbro quality, they have had problems with fake Chinese knock-offs for many years. Some guy buys a “Walbro” off eBay for cheap, not stopping to wonder WHY it’s so cheap, and then bitches about early failure on whatever forums he’s on. Buy direct from the manufacturer and save yourself the headache.

 

[Corvette Ed]

Smack the bottom of the tank a few times with a big hammer if it doesn't pump.

This has worked for me a couple of times,just to get me home.