Saber

iTrader: (2)

I havent really heard anyone talking about fuel pumps and which ones were best suited for our applications other than two things, get a walbro or get a 350TPI one. I prefer to order my parts from summit, as i have a nice little cupon from an order they messed up not too long ago and they dont seem to have walbro pumps? And they say they dont have any pumps that run at 155LPH unless its for a mustang, And he swore up and down that a stock 305 replacement would work well, but after me telling him that i have read from you guys that the factory pump is garbage, they did recomended a BBK high volume pump rated at 255LPH but they said that is a huge step up for my application and highly unnessicary. Heres my question, im looking for a direct replacement for a stock pump, i have never done a fuel pump before and i would have no idea as to what is involved in making one fit thats not a direct replacement, ill be running 65lbs/hr injectors through stock 305 heads and cam, which will eventually be swapped out at the end of the summer for a cam and 350TPI heads. Could i make it by with a 350TPI pump? of should i get the bigger one? Im not too good with fuel delivery unless its carbed so any help would be appreciated as to what fuel pump i should get, a 350TPI one or another aftermarket one that seems a little bit too much.

RBob

iTrader: (1)

If you go too large with the fuel pump you will lose control of the fuel pressure. With a basically stock 350 all that is required is a stock TPI pump. Or the 190lph (?) Walbro pump (I can't recall the exact volumes on all of the pumps).

If you go with a Walbro 255lph and try to run the TBI at 13 psi, it won't happen. There is so much flow that the fuel pressure will increase beyond what the TBI unit and return line can handle.

Recall that any unused fuel needs to be returned back to the tank. This is where the problems arise.

Then note that a TPI pump is rated at 43.5 psi. Lower the pressure to 13 psi and the flow increases.

Now if the engine makes enough HP to require say 18 to 24 psi with the 65 #/hr injectors (making them flow more fuel), then a Walbro 255 lph pump will be OK.

It ain't easy.

Not to mention that the fuel pump wiring will also affect the flow rate of the pump. More voltage to the pump is more flow from the pump.

RBob.

Timothayyy

iTrader: (2)

I went with the walbro 255lph, got braided lines [both fuel lines], and an external regulator, had to lower the pressure too about 11 and its perfect.

I wouldent go with the 255 unless you have the extra time and money to get an external regulator and new lines.

But yeh if you just want a new pump then go with a 190

Saber

iTrader: (2)

Is the 190 a direct replacement? As i said i have never done a fuel pump before so im looking for something fairly straight forward. Or would the TPI pump be the best bet? from what i gather if i use the TPI i will need to use an external regulator? Im going to do the fuel lines that come off the tank at the very least, as i have heard that the fuel lines go over the tranny so if they do i wont tackle that job at this time. but im sure i could install an external regulator somewhere on the fuel line that i put in, ill do a search on a regulator as i have never even seen an external one before. Would i also need a regulator if i used the 190?

Also does anyone know a good site to buy all of this stuff off of besides summit? id be looking at getting a pump, and possibly a regulator and some lines if needed.

Timothayyy

iTrader: (2)

http://www.fullsizechevy.com/forums/...-tbi-pics.html

All the fittings and everything fit just fine. I got the same regulator with a Walbro 255, only difference is I have all new braided lines all the way too and from the pump. I got my Walbro 255 from some import web site [came as an 82-92 Firebird kit] for like 100$ and it came with everything you need as far as the pump goes and I love it. If you plan on doing a lot of upgrades to your car go with the 255 and the Aeromotive regulator with new lines. If you just need a new better then stock pump just grab the 190.

Saber

iTrader: (2)

Thanks ill check out the 255 and 190 and see which one will be best for me. How much did your total install cost you for a 255 with the regulator and braided lines all the way up front, and how hard of a job is doing braided lines? i have heard that the lines go over top the trans? is that true?

Timothayyy

iTrader: (2)

Far as the lines go I had some friends help me and they did that while I was grabbing food, lol. Even if it goes over the trans I dont see why that would be a problem? But the only tricky part is cutting all the lines and getting the fittings on them. I measured everything out and took it to a shop I go to a lot they cut it all and put my fittings on for like 10$. Dont forget to get a new fuel filter also.

But the total cost was about 400$. It was like 100$ just for fittings, lol. Then the line is pretty expensive, plus the regulator and an AC Delco filter.

But the lines you could do yourself long as you can figure out a good way to cut them, overall it wasent that hard. But if you go with the 255 you should really get it tuned, I ran extremely extremely rich, fuel pressure wouldent go any lower then 11 without the pressure going crazy [guage just jumped around]

Overall if you want to keep things cheap and simple just go with the 190.

Saber

iTrader: (2)

Ill probably wind up going with the 190 just to make things easier, im going to get the car tuned sometime soon because it still has a 305 chip and it will run like crap once i put the new pump on and throw 65lb/hr injectors on it. I need to replace my fuel lines however as they are quite rusted, now braided being the most expensive and from what i gather, braided lines are required for a 255 but what about the 190? If i do the lines in regular steel lines and throw a new filter on there would that be sufficent for the 190? Also while im putting new lines on i may as well throw on an AFPR also, or will that not be needed? Does the 190 pump at more psi than i would need for my TBI, which will be running a set of 65/hr injectors? or will the stock regulator be sufficent enough?
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Timothayyy

iTrader: (2)

From what I gather just the 190 and a new fuel filter should work just fine. I only recommend getting the new lines done for the return line so it doesent bump your pressure up too high, and while your doing the return line, might as well do the sending line also, which is what i did.

But just get the 190 and a new fuel filter and the stock regulator should be fine. No need for anything else. But maybe someone with the 190 will chime in.

Why are you going to get new injectors though?

Saber

iTrader: (2)

I did a 305 to 350 swap and im running stock 305 injectors, and from what i hear the stock 305 injectors suck, so i sourced a pair of used cop car injectors. I figure ill throw on a new Fuel pump and the sending and return line and than put the injectors on it and get it tuned. Also down the road ill be putting on a set of TPI heads probably and a mild cam. So mainly the reason behind injectors is to complete the swap, unless of course the stock 305 injectors are not holding me back as of yet, but im pretty sure there 55lb/hr for a 305, 61lb/hr for a stock 350 and 65lb/hr for a cop car and since the car needs to be tuned, i may as well tune it with new injectors.

Timothayyy

iTrader: (2)

The stock 305 injectors should be fine if u get a external regulator, just raise the fuel pressure.

Saber

iTrader: (2)

Hmmmm when i read the sticky it said you should get bigger injectors, or at least 350 TBI injectors. Would putting on 65lb/hr injectors give me any gains in performance over putting in an external regulator and keeping the stock injectors while turning up the pressure? Would this cause the stock injectors to push out more fuel? Im looking to build a quality car that can be driven daily and still make decent power for maybe some trips to the track so i was asuming the best way to go would be bigger injectors and such.

Timothayyy

iTrader: (2)

Yes if you get an external regulator and remove your stock one it will increase the flow of the stock injectors because there is more pressure pushing the fuel out.

Im not extremely experienced, im just telling you what i understand and what ive learned from working on my car.

Saber

iTrader: (2)

Hmm thanks, ill have to look into that more and which alternative will be the best fit for my car, but i didnt know that before so now i can spend the rest of the day at work researching that lol. Thanks for your help on the Fuel pump though, i will be going with a 190 and steel lines, i just have to find a 190 offline somewhere now.

Timothayyy

iTrader: (2)

Yeah Walbro makes real good pumps, and im totally happy with my set up. I have the exact regulator I linked too above and I really like it.

Let us know how it all goes and take some pictures!

BronYrAur

iTrader: (1)

Go here: http://www.autoperformanceengineering.com/

Click on "Applications" on the left pane, under GM the Walbro 190 is $83. That's what I have, it installed perfectly, all parts included. Make sure you use the high pressure short line for inside the tank that's included because I believe if you reused the stock one it would blow apart.

Just make your stock regulator adjustable, it's simple and outlined in teh Ultimate TBI tech article how to do it.

As for injectors, the flow you get out of an injector is: Original Inj Size * sqrt(new pressure/orig. pressure) = New Inj Size.

EG. I'm running stock injectors at 21psi. So this is equivalent to 72.75# injectors. 55*sqrt(21/12)=72.75

DM91RS

Oh Jim you and your square root............

What BronYrAur said.....

My question and sorry if I missed it somewhere is how do you know how much fuel you are needing? Have you datalogged or are you going by what you read?


DM

BronYrAur

iTrader: (1)

haha

good question DM

Aaron91RS

iTrader: (2)

just get an L05 pump and be happy you saved money and effort.

Saber

iTrader: (2)

If your asking me that question, i dont know how much fuel i need actually, ive been going as closely by the 350TBI swap thread as i can, now datalogging is something i have recently read about after i started and im going to go through tbichips.com for my chip, and ill probably data log right before that. Since im new to TBI im pretty much going by what i read and learning the hard way, But now from what you guys have told me, i can keep my stock injectors from the 305, and with a regulator and some datalogging, ill be able to get them to exactly where i would need the injectors to be at for my current build, and when i perform upgrades i could simply just datalog and turn the pressure up if need be, which would increase my injectors lb/hr?

I had just assumed from the sticky, that when doing the swap, and doing all the stuff posted and burning the chip i would be all set, but this seems like a much less expensive alternative, almost as if by gettign the 65lb/hr injectors i would be wasting my money.

BronYrAur

iTrader: (1)

I totally disagree with that, why go to the trouble of dropping the tank and installing a new pump just to put an inferior GM pump in that can barely support the volume needs of an L05. For $83 you get a 190 Walbro, not expensive at all. Either way you have to drop the tank and install, so I don't know where the saved effort comes in to play.

Saber, tbichips sucks. You'll be wasting your money and getting a half-arsed chip that will kind of run your engine. You'll never get the full potential out of that 350 without doing the chip burning yourself. It isn't hard once you dive in. All you need is a cheap laptop, $80 Burn1 from moates.net, ALDL cable to datalog and all the software is free.

DM91RS

How much does he charge for those chips?

Wonder if I could get a high performance chip for my EBL?

Aaron91RS

iTrader: (2)

And here it ran my 383TBI with 85pph injectors, trickflow G2 heads, etc etc.
Glad my engine didn't know it wasn't supposed to work.

BronYrAur

iTrader: (1)

Yeah, I bet it ran it just fine. But what was your AFR at WOT and about 5500RPM or wherever you happened to shift? You ever put a Wideband on it? Don't be a smartas just because I said a Walbro pump was better than a stock TBI pump.

Aaron91RS

iTrader: (2)

It wasn't lean if that's what your implying.

BronYrAur

iTrader: (1)

Not so much implying it as suggesting it as a possibility. I think it's possible it supported that motor, maybe, but it wouldn't hold up for long at that volume/pressure requirement, that's for sure. Unless you were able to monitor your fuel pressure at full load, you don't konw for sure if it was dropping.

Basically, the point is, buy a good pump and do it once so you never have to drop the tank again.

Darkshot

iTrader: (4)

I walked into a local parts store and bought a ACDelco TPI 350 pump and put it in place of my blown stock TBI pump. Pressure went from 11 to 13 on the stock regulator, but thats it. I adjusted for the small pressure change in the bin and it runs fine.