Performance Fuel Pump?

[Lazzman]

Anyone ever install a performance fuel pump in there modified X? Talking to my installer the other day and he said even mild mods could benefit from an upgraded 190lph pump. I also read in Popular Mechanics that stock fuel pumps are designed for stock engines and do not have the capabilities to feed even slightly modified engines.

For my V6 sohc he said I should at least use a V8 replacement pump. I think he is on the right track because with my 4.10's and heavy foot my engine sucks up lots of fuel.

This is not a complete new in tank fuel pump system, but rather just the pump that needs to be installed in the original apparatus. They are not to expensive as I believe BBK and Holley both make them, for around $120

 

[410Fortune]

Your pump is fine until you get into some heavy mods, like a blower.
The pump will not boost fuel pressure,the fuel pressure regulator is in charge of that (sends everything over whats needed to maintain fuel rail pressure back to the tank)
You will need larger injectors before you need a higher PSI pump.



the V8 uses the same injectors and intank pump as your SOHC. SOHC and 5.0L use 19# injectors, stock the fuel systems on the two trucks are identical when it comes to the pump, tank and lines.

A fuel pressure gage will tell you if your rail pressure drops at WOT enough to warrant the need for a higher PSI pump, and again larger injectors would be first. Injectors are calibrated to the MAS and PCM so those need to be tuned in order to run larger (24#) injectors.

Big tires and gears will not starve your engine for fuel, high performance mods that allow more air to flow might, but not until your SOHC is pretty heavily modded.

Now somebody please correct me if I am wrong here

 

[spindlecone]

Well said 410. exactamundo, still wondering if Lazz got his other potential fuel issues resolved

 

[410Fortune]

See sometimes I have a clear head and memory about this crap! Sometimes I am just plain dead wrong, or a little off! hahahaha
there is not enough room in my head for all of it, much like Kelli from the Bundy family

 

[aldive]

Talking to my installer the other day and he said even mild mods could benefit from an upgraded 190lph pump.

I think I would find a more knowledgeable installer.

 

[Diddy74]

Fpr

Just wanted to chime in on this disscusion on fuel pressure. I replaced my IAC and fuel filter. Idle and acceleration has improved slightly. I still feel like the engine is either starved for fuel or I have a vacum leak. I'm assuming a vacum leak symptoms would reamain constant under all driving conditions,but fuel pressure could be intermittant as my sluggish accel and occasion rough idle seems to diminish with less than 1/2 tank of gas. So my $60,000 question is...on the 99 xlt v6 sohc where the blazes is the FPR? Chilton manual once again is very vague

 

[410Fortune]

A fuel pressure TEST would be the first thing to do if you feel you have a weak pump.

 

[aldive]

So my $60,000 question is...on the 99 xlt v6 sohc where the blazes is the FPR? Chilton manual once again is very vague

I don't think you have one.

 

[Diddy74]

I don't think you have one.

So once I determine I do indeed have a fuel pressure issue, what should I be looking at to replace or "tweak"?

 

[aldive]

So once I determine I do indeed have a fuel pressure issue, what should I be looking at to replace or "tweak"?

You don't have an FPR. FP is controlled by your ECM.

 

[Diddy74]

You don't have an FPR. FP is controlled by your ECM.

Ok. i'll have to investigate further. No CEL just feels like i'm losing power somewhere when trying o accel on the highway, or in heavy traffic I get an occasional rough spot at the idle or low rpms

 

[aldive]

Have you tested the FP?

 

[Lazzman]

Diddy, sounds like your having the same issues as me. I have a serious suspition that my fuel pump is malfunctioning and I could care less what some people may think.

I have spent hours and hours researching this, I have had it to two dealers who won't touch anything unless the truck is not running at all. I can feel it in the pedal when the throttle is past 1/2 and tach heading above 3k rpm that there is no oomph. The idle is very weak and no it is not the IAC Valve which I just replaced, a waste of $100.

As I said in a previous thread fuel pressure with key in on position is 12psi, in reality it should be 45psi when pressurized. Upon start up it should stay rock solid at 30psi. Further, I ran my vehicle bone dry twice and was stuck on the side of the road, perhaps the best way to damage a fuel pump. Also the vehicle has 137k mi on the clock, 'nough said. My only regret is that I lack suffiecient equipment to check the pressure under load, though I could have put the brake on and hit the gas.

We shall know soon enough. Besides the price of a 125gph pump is about the same as the stock unit- so why take chances, fuel pressure regulation has nothing to do with how much gas your engine uses under heavy throttle.

To Aldive, you always suggest getting a new installer or tuner- have you read the posts or are you snorting to much Permatex?? There are other tuners out there besides your fabled Doug from Bama. One of the tuners who did my truck, tuned the Fastest Mustang in the World on 10.5 slicks and has an engineering degree from MIT. The other one has forgotten more about tuning than most will ever know. New England is a heavily populated area and we have some of the best techs.

 

[Diddy74]

Not as of yet, time restraints. I guess my question was assuming that I do indeed have a fuel pressure issue, where should I be looking to remedy it?

 

[Lazzman]

I would check the fuel pressure at the schrader valve. Buy a gauge at Autozone for $40.

If the pressure is fine go through the system, also check the VIS Valve, making sure it is operating properly.

 

[aldive]

To Aldive, you always suggest getting a new installer or tuner- have you read the posts or are you snorting to much Permatex?? There are other tuners out there besides your fabled Doug from Bama. One of the tuners who did my truck, tuned the Fastest Mustang in the World on 10.5 slicks and has an engineering degree from MIT. The other one has forgotten more about tuning than most will ever know. New England is a heavily populated area and we some of the best techs.

I was referring to the "tuner", the gentleman mentioned as his mechanic. And as Jamie pointed out, I don't feel that this one has a clue as to his problem.

And if you would listen to advise give you on this board, maybe you could resolve your problem.

Oh, by the way, why havn't all the hot shor "pros" where you are from resolved your problem?

 

[Diddy74]

Ok Ok I get it lol I'm looking for the medicine before I determine the illness. Its just my curiosity to know what i'm possibly facing because the idea is keep the snowjob to a minimum when venturing out in to the automotive repair world. You guys have been a great help with lots of things that otherwise might have been blown out of proportion by unsavory or just down right incompetent shops. Its hard finding an all around "good" shop. Some are just better at diagnosing and repairing certain things than others. I have a guy that I trust and does excellent work but due to circumstances isnt equipped to do all kinds of work.

 

[410Fortune]

I know that guy! hahaha

 

[aldive]

Before you go and pay someone to diagnose your woes, check your FP yourdelf. It is very simple to do.

Good luck .......

 

[Diddy74]

Before you go and pay someone to diagnose your woes, check your FP yourdelf. It is very simple to do.

Good luck .......

Will do, quite a few other things of moderate difficulty you guys have been a great source for information and knowledge...lol i'm starting quite the collection of misc tools..not a bad thing but leads me back to one of your previous threads..WHERE TO PUT STUFF? Since I dont have a garage its not practical to lug tools and stuff back and forth I prefer to leave them in the truck for use whenever I might need too. I havent found any decent storage containers that arent commercial grade or for the soccer mom to organize groceries in.