I might need a fuel pump. Which to get?

[SpeeednV6]

It seems I have another issue. My fuel line is rusted out by the fuel filter and needs to be replaced. Easy way to fix this?

 

[Ttype6]

It seems I have another issue. My fuel line is rusted out by the fuel filter and needs to be replaced. Easy way to fix this?

There's not going to be an easy way because of the tight bends and limited space. You can buy sections of line that have the Saginaw fittings on one end of the line. When you see one of these,you'll get a good look at the restriction that the Saginaw fitting creates. You can bend the line and flare the other end. You'll need to go to a section of your original line that's still in good shape to cut and flare it. Then you can use a female to female flare junction.

 

[SpeeednV6]

I'm pretty fortunate that I don't have those fittings at the filter. They were cut out long ago to put a larger filter with male, unthreaded ends. I did not do this. The first mechanic to ever touch my car did this. The filter ends are 1/4 on both sides. I have to find a filter with larger ends. I might try to cut out the bad section and replace with rubber hose. Ttype6: I did read many of your posts concerning those restrictive fittings. It makes sense to enlarge them, especially back in the day, guys were going 10 sec. without touching the line. At which ends were these located?

 

[Pronto]

All except at the sender and begining of the out and in lines, rubber there.

 

[SpeeednV6]

What rubber lines did you use? What size? How long?

 

[Ttype6]

I'm pretty fortunate that I don't have those fittings at the filter. They were cut out long ago to put a larger filter with male, unthreaded ends. I did not do this. The first mechanic to ever touch my car did this. The filter ends are 1/4 on both sides. I have to find a filter with larger ends. I might try to cut out the bad section and replace with rubber hose. Ttype6: I did read many of your posts concerning those restrictive fittings. It makes sense to enlarge them, especially back in the day, guys were going 10 sec. without touching the line. At which ends were these located?

Since you're Saginaw fittings before and after the fuel filter have been eliminated,the only two left are where the supply line exits the frame rail by the power steering box and where it attaches to the fuel rail. You don't,necessarily,have to drill these. Your fuel pressure gauge will tell you if it is necessary. If it bounces at full throttle pressure,drill them . If it doesn't,don't. I like to avoid this if possible because you are introducing shrapnel into the fuel lines,so you need to be very thorough when flushing them.

 

[DeatschWerks]

I'm a little late to the party on this response, but I felt it warranted a response.

We performed our own in-house testing regarding the DW300 and heat build up. We tested multiple samples of both the Walbro 255HP and the DW300 at high ambient temperatures (>90°F, have you seen how hot it's been in OK? 110°+!) and in low volumes of fuel (1 gallon) to simulate conditions which may lead to excessive heat. We tested all pumps under the same conditions (pressure, voltage, and ambient temp) for 90 minutes each and recorded the fuel temps every 15 minutes. Our results showed only slight increase in heat build up (~7F) with the DW300 pump. Plus the DW300 exhibited no significant decrease in flow at higher temperatures when compared to the walbro 255. Our conclusion was that the slight increase in temperature was due to the increased current draw of the DW300 which is a byproduct of increased flow.

 

[Nick Micale]

...............This is an unwise thing to do and another unfortunate thing that happens in the world. Does it change the fact that the installation of a DW pump might necessitate the modification of the fuel return line?

If someone installs a double pumper,made with two Walbros,the fuel return line will never have to be modified. The second pump doesn't come on until the motor is using a good amount of volume produced by the first pump. If the second pump was allowed to turn on at an idle,you would,of course,overwhelm the return line. This never happens when the pump is turned on,only,when the motor needs it and,again,has nothing to do with the fact that installing a DW pump might require the modification of the fuel return line.

We have already established that the installation of a DW pump can require the modification of the fuel return line and WILL heat the fuel more. Why are we still talking? These are the only two points that I wanted to add to the list of aspects of running aDW pump so a person looking to by one will be able to make a more informed choice. .

I figure you are actually a good guy and well meaning, but please do NOT make statements as facts which you cannot verify.

Many owners have posted that installing a DW pump did NOT require them to modify the fuel return line, so you are way off base there.

When you made the statement that a DW pump "WILL heat the fuel more", I did not believe it, but decided to get a REAL expert to provide some data which is now shown as actual test results that it does NOT heat the fuel more, but the Walbro does?

So again, please do not erode the credibility of our board by stating your opinions as facts!

 

[RmvBfrFlght]

Oh, I'm going to regret this post, but, was this test done with fuel rails at engine temperature? This is where the fuel tank gets the majority of heat from, not the pump itself.

The fuel is being circulated though lines along with the rails which are hot due to heat from the engine. This heated fuel is then returned to the tank. The fuel tank heats up.

This is the major reason the more recent cars, typically starting with the LS1 series of engines (GM stuff here) have return-less fuel systems. And they typically run at 58 psi to prevent boiling of the fuel in the rails.

The return-less system is for vapor emissions. Hot fuel in the tank puts out more vapors which then need to be captured by the charcoal canister system. And burned off though the engine at the proper time. A number of years ago, I toured a major auto manufacturing facility. The drive was to control evaporative emissions.

Charcoal canisters were becoming quite large and could retain pounds of fuel from vapor.

Of course, the question really is, which still needs to be answered, does a slower flow of fuel (255 LPH) through the rails pick up more or less heat then a faster flow of fuel (340 LPH) though the rails? And which flow heats the tank fuel more or less?

RemoveBeforeFlight

P.S. I know this post is going to haunt me... BUT IT SHOULDN'T!

 

[Ttype6]

I figure you are actually a good guy.

I figure we're,pretty much,all good guys till a girl moves in with us.

Many owners have posted that installing a DW pump did NOT require them to modify the fuel return line, so you are way off base there.

Yes they did.
You reported that Richard Clark found that fuel pressure was a potential problem.
You explained the details of a test that you were a part of in witch the fuel return line was Modified.
Three people in this thread,including Eric Marshal,noted the same problem.
That's a total of five people in this thread,including you,who acknowledge this problem.
Six,including me.I assume we are all off base.

When you made the statement that a DW pump "WILL heat the fuel more", I did not believe it, but decided to get a REAL expert to provide some data which is now shown as actual test results that it does NOT heat the fuel more, but the Walbro does?

So,you're saying that a fuel pump that flows more fuel to a hot motor (and therefor returns more fuel back to the tank) doesn't heat the fuel in the tank more than a pump that moves less fuel to a hot environment (and therefor returns less fuel to the tank)
You're,also saying that a fuel pump that requires more amperage,to do more work,doesn't heat the fuel more.
And,also your saying that the pump that flows less and draws less amperage,actually heats the fuel more than the higher flowing,higher power drawing pump.

People are going to get the impression that you will defend this thing until,well you know.

So again, please do not erode the credibility of our board by stating your opinions as facts!

Please! Please! Quote any of my statements ,in this thread,pertaining to fuel pressure or heat that aren't factual.

Please refer to post 127.

 

[Ttype6]

This is the major reason the more recent cars, typically starting with the LS1 series of engines (GM stuff here) have return-less fuel systems.

I mentioned this in an earlier post. The facts are argued here,but no one argued this one.

 

[RmvBfrFlght]

Plus the DW300 exhibited no significant decrease in flow at higher temperatures when compared to the walbro 255.

This is an interesting statement. The reason is that on another board there are many folks having issues with apparent fuel boiling in the tank, or at least at the inlet to the pump. The cars die after driven in high temperatures (90* F) for a period of time. Typically about an hour.

Most are running a Walbro with others running an AC Delco replacement pump. It is driving these folks a bit crazy. The problem manifests itself as a loud pump (howling or woo-woo-ing) then the fuel pressure drops and the engine dies.

Can get the fuel pressure back by either sitting for an hour (cools off), or adding fuel to the tank (cools off quickly).

With a low(-ish) mileage stock pump in the same basic car I haven't had this issue. Maybe pump design has something to do with this problem? By your statement it may be.

RemoveBeforeFlight

 

[Quik Six]

With the "personal" BS behind us, I would like to answer a few points in this thread.


Our goals on this and other test vehicles are:

1. To run a TR deep into the 10's with one DW pump.

2. To run a TR into the 10's with E-85 and one DW pump.

3. To run a daily driver GN with one DW pump and slightly modded fuel system 11.5 on E-85 with a stock computer and TT chip.

Since track time is very limited with our summer heat, results are a couple months away, but the cars are ready!

Nick: I run a single DW with stock lines and ported couplings. Run a TT SD chip with 80# injectors at 43# FP per Eric's instructions. I also run a 15# halo nozzle with single line Razor kit because it's hot in Oklahoma too.

Best time is 10.37 @ 132 with crappy 60' of 1.59, 24-25#'s of boost and broke 3 ring gear teeth on the run.
The DW pump maintained very consistent AFR of 11.2 and IDC stayed in the 78-80 range for most of the last half of the track with a MPH gain of 27+.

This is a true street car with stock ECM hauling 3750# with driver so I believe I've shown goal #1 is achievable.

I'm a big fan of the DW pump.

 

[DeatschWerks]

Hey RemoveBeforeFlight,

I hung around when they were doing the heat testing. Toward the end of the 90 minutes, the fuel in the 1-gal bucket was around 160-165°F.

I think the fluid was around 85-90°F when they started.

 

[Ttype6]

Nick: I run a single DW with stock lines and ported couplings.

Did you modify your lines in anticipation of a fuel pressure problem at Idle,or did you note a pressure problem after installing the pump and then modify.

 

[Pronto]

This is getting alittle boring. The point of this fuel system upgrade it to move away from stock performance. You are entering the world of performance modifications. GM engineers designed the TB to perform to a standard level. Here we go re-engineering it to go up to higher level. You can certainly expect something else that needs to added, changed, modified, tuned, tweaked or eliminated when you add any kind non-stock high performance parts. Nature of the beast, right? At least that's been the way for me for most of my performance mods. So, if someone decides to use the DW fuel pump, according to board members there is a possiblity they "may" need to do some mods. Information is on this great board on a few ways to do it if need be. If they have an issue they have answeres to it. Seems simple enough to me.

 

[Quik Six]

Did you modify your lines in anticipation of a fuel pressure problem at Idle,or did you note a pressure problem after installing the pump and then modify.

That mod was made by my mechanic when he replaced the stock pump and regulator at the first go round of mods which were done in early 2001.

 

[Ttype6]

That mod was made by my mechanic when he replaced the stock pump and regulator at the first go round of mods which were done in early 2001.

Did he do the supply and return lines?