Just thinking aloud here...


Would it be possible to use the existing steel fuel line from tank to front of car to feed an EFI fuel pump.

From there it would go to a pressure regulator.

The pressure regulator would go to the FI-Tech and back to the tank using the other steel line.

Possible or nuts ?

 

Use the Holley in tank self regulating module.....about $350. No need for return line at all.
What does the Fi-Tech call for pressure wise?

Jebby

 

Oh, now this sounds interesting. 58 PSI.

 

That steel fuel line is 50 years old. It has been vibrating for 50 years. And designed to pass fuel at a slight vacuum. If it's got a stress crack in it it's gonna be pumping fuel all over your exhaust at 58PSI and the car still going to be running. I would use that steel fuel line as the return. there's no pressure on the return. And run a feed line that's designed to handle that much pressure and younger than 50 years old.

 

Sniper calls for 58psi.

Jebby

 

I am useing FiTech, it is 58lbs, FiTech has built in regulator, i used new feed line, and used old feed line for return,, My FiTech uses a return,, you can look up my posts on what i made,, very easy to do,,,,,(( its a '75, used origonal fuel tank ))

 

Also, look at the LS filter/ regulator combinations. 58 psi, easy to use.

 

Hello again Dorian,

I bought a a new Holley EFI system from a company in Florida and they suggested the Holley Fuel Tank Module as an alternate to buying a new tank with fuel pump in it. I received the Holley Module and it went in my C3 in about 25 minutes. You remove the old sending unit and replace it with the new Holley module with the pump built into it with the preset regulator at 58 psi. My sending unit installation hole was on the bottom of the fuel tank so I drained the tank and swapped out the units.

Now my new Sniper Stealth 4150 works great. What a nice system with so many features. It has an incredible software package that lets you set it up any way you want it. The company I bought mine from sold me everything for less than $1700 and they have a Holley Tier 3 technician on their staff who helps you with your system setup and handles any questions.

The name of the company is EFIsystempro.com and they have great prices but the best support of anybody I spoke to when trying to decide where to buy it. My parts arrived in two days and the the Technician had already made contact. He gave me a cell number for customers only and an email address.

The Holley Software that works with the Sniper is downloadable so you can take a look at it. It has extra inputs and outputs for you to set up to do whatever you want. I spray water/methanol into my 427 when hot and the software can do that with no problems. It also replaces your ignition system if you want to, I am still using my MSD system with the Sniper. If you have any questions I would be happy to try and help. I suggest you check out their website at efisystempro.com to learn more about what Holley has to offer.

Their module is a no-brainer as not running a return line is really handy. The instructions for the systems are downloadable and interesting to read. Holley insists that you run the power wires directly to the battery, this avoids any noise from other components. The Sniper's can be adversely affected by noise in the signal wires. Just be careful staying away from ignition wires and everything will work out. Holley uses CAN Bus so you can have several gauges using one wire. It is the same as most auto manufacturers are using. The system is designed to operate your electric fans and has controls built in for two fans.

It is so nice to simply "turn the key" and have the engine start right up and fast idle until it warms up and then it drops to the 850 rpm where I set it. I bought the plain silver unit and saved $50. The whole system was $300 less than I had budgeted for the swap. It looks great on the Corvette and nobody knows that the Corvette is fuel injected instead of having a carburetor. The little hand held touch screen shows the vital information and you can customize the daylights out of this system using it. I also have a PC cord that allows my laptop to monitor or change any of the settings. I have yet to hook it up to the laptop as I have had no reason to.

 

Hey @ctmccloskey good to read you again . I think I will spring for your solution.

I just discovered two more issues that are becoming final nails in the coffin of my current EFI setup.

I have the Fi-Tech GO EFI Classic 550HP. It’s easy to connect, but it looks ridiculously messy under the hood. As much as I like EFI, this one is a bit embarrassing. People invariably ask you to pop the hood, and when you do it’s a mess under there! Cables, ECU, fuel sump...

The Fi-Tech I have doesn’t come equipped with a fuel pressure regulator, so I paired it with Edelbrock’s ProFlo fuel sump system. It is preset at the required 58 PSI. But again, it is additional clutter under the hood.

Today I discovered today, that both the Fi-Tech ECU and the fuel pump failed in some measure.

After going through two relays, I found that the ECU was giving power but not grounding the relay for the fuel pump the way it was supposed to. This led to the fuel pump randomly shutting off and spawning a brood of gremlins

Providing an additional, independent ground for the relay made for much smoother operation. Still, there’s an issue somewhere inside that positronic brain.

The other issue was vapor lock. As a test, when at full hot, I shut the engine off and tried to turn it back on. Nope. No start. I figured it might be the electric fan robbing start power, so I temporarily disconnected it. And that’s when I heard it... bubbling inside the ProFlo fuel sump.

This is just too messy.

I’ll definitely be moving to something more recent. The above solution seems exactly what I am looking for.

ADD - Also helpful because my fuel level sending unit is clearly off...

ADD - It may have been a bad relay after all. The EFI kit removes ground a few seconds after turning the car on position 1, after it primes. Once you crank and the car is running, it restores the ground and turns the pump back on. It might have been a combination of bad relay and vapor lock. ...and cranking while the electric fan is on.

 

@ctmccloskey quick question... how did you plumb from pump to the throttle body Twist-Lok ?

 

Where'd you put the fuel sump that it gets hot enough to boil the fuel in the tank? It should be cooled by the fuel pumped by the mechanical pump which is circulating from the main tank through it and back to the main tank.

It'd be damn near impossible for your under hood temperatures to be high enough to boil or vapor lock the high pressure 58psi fuel.

 

Hello again Dorian!
The system I bought from EFIsystempro came with 20' of Earls Vapor Guard Hose and the necessary fittings. Since there was no return lines needed it was really simple to do. My original fuel line rust through decades ago so I ran new Earls hose the length of the chassis to the fuel input fitting which was a -6AN hose connection. They supplied me with a adapter that went from the -6AN to a hose barb and utilized fuel injection type clamps. The hose went from the tank to the throttle body without any problems. The fit of the tubing over the adapter was very tight and I doubt that will slip off even with 60 psi and double clamped... Paranoia will destroy ya....

On my C3 you can't tell that I have fuel Injection as the throttle body looks like a carburetor to start with. I will take a picture and try and upload it so you can see what it looks like. I am going to replace the Earls Hose at some point and go back to a section of -6 AN Stainless steel braided hose like it had been before. My fuel lines are inside a insulated hose cover with a Silicone Fire Protection cover on top of that. This way the fuel is not heated up before getting used. I ran the tubing insulation an 99% of the hose and the fire proof stuff inside my engine compartment. Since I have a 427 with the Compression it makes a LOT of HEAT and there is no way I would put a sump with gasoline in it next to that engine. I even have my heater hoses insulated to protect them from the heat that comes off my headers. I have to do something about the excessive heat as it damaged the paint on my Hood from underneath.

The wiring harness that is built into the throttle body had the fuel pump relay and a fuse between it and the pump. Drilling a hole for the O2 was the biggest issue I had to deal with. There was one long Blue wire in the harness and they want that to attach to the fuel pump. I ran a wire from the battery negative to the fuel pump instead of using the Chassis ground. The fuel pump comes on when you first turn the key to "run" and it primes the system and shuts off. It is just like the fuel system in my C4 and like the C4's you don't hear the pump when running.

Take a look at your fuel tank and see if you see the little round plate with the fuel level sender on it. It is on the top of many car's fuel tanks but on my C3 it was located on the bottom. It made it so easy to install the fuel pump and the Hydra-Mat as I folded them to get them into the tank hole and then I spent most of my time trying to get the round plate re-installed. I hope your is on the bottom like mine was, this way you don't have to remove the fuel tank. I was ready to pull my fuel tank myself when I realized that the hole on the bottom of the tank was what I was looking for. Removing the fuel tank is fairly easy but not having to remove it made me much happier

When I bought the system the tech told me that a majority of EFI issues have to do with electronic noise in the system. He really emphasized this and made sure that we ran the power for the EFI straight to the battery. I was real careful to run the wiring away from the ignition wires. I too have a MSD ignition and that is not exactly optimal but with some modifications to my MSD distributor I can still use mine. I need a distributor with a mechanical tach drive and this MSD unit has one. I need to lock out the centrifugal advance mechanism and remove the vacuum advance unit and then I can let the Sniper control my timing and fuel which is my ultimate plan. The tech suggested that I get one part working before tackling the ignition side of things. Does your Corvette have a mechanical Cable driven tachometer as well? The system I have provides a tach output allowing you to use the factory tach IF it is electronic.

I looked very closely at several of the popular EFI systems and decided the Holley looked very well designed. The possibilities of what it can handle is amazing. If I had been smarter I would have ordered a Super Sniper as it has more owner configurable inputs and outputs. The data-logging is really handy and extremely versatile. Whoever designed this system built it like OEM quality and intended it to be left alone without needing any further tuning. It takes a couple hundred miles to get it to fully learn all the Engine and the way that you drive it.

I have never uploaded pictures so I may give it a try and show you what my system looks like. My paint job on the hood and the rest of the Corvette is really bad but the engine looks nice.

Dorian, you might want to order the Holley Fuel Tank module from EFIsystemPro and that way you would be eligible for tech support from Chris the Holley tech. That is if you are interested in using one of these systems. I did not know they existed until recently but the module sure solves the fuel supply issues.

Be Well and Stay Well!
My very best to you and your family!
Chris

 

Hi Chris

I am hereby compelled I will give the company a call. I will do it in two steps - first replace that Edelbrock sump with the Holley Fuel Tank Module; It does indeed look like a perfectly elegant solution; the most obvious ones always are; I wish I had known about it earlier. Then the next step will be a Holley Stealth EFI ; mine is just too cluttered.

The final goal would be an even more stock looking (than my HEI) small cap distributor that can be controlled by the ECU... and run a mechanical tach. With bling-tin around it; it should have even more of a stock appearance.

Hmmm, my very first move however is to move the power source for my ECU straight to the battery and not my heavy duty junction box. I am tempted to move the ECU ground straight to the batter as well.

If you would upload some pics; that would be swell.

I am intrigued by your 99% insulation.
That seems a wise idea. What insulated hose cover did you use ? Only inside the engine compartment ?

@lionelhutz I can't explain it but I hear it bubbling in there, big time The sump is mounted near the passenger side control arm. The fuel sump features a pair of floats that stops fuel and sets the fuel level in the bowl. Presumably that is what I hear bubbling away. I doubt there is any circulation or cooling effect from fuel circulation as there is only a vapor return line back to the tank. Today I will check the vapor return line to see it it is plugged, just in case that makes a difference.

Take care, Chris !!!

 

Ah, I'll bet you're talking about this stuff...

 

One more question... how noisy is your Holley Sniper? The IAC and injectors makes a good racket on my FiTech.

 

I cant even begin to imagine all the issues you are having,,, I'm running FiTech, and no one can guess I have throttle body injection,, no noisey injectors, , quite under the air filter, , smooth operation throughout,, so sorry to hear of your bad experiences,,, I hope you have better success with another brand,,, but my belief is it all depends on proper installation, , take the advice from the guys here, and you should have great performance from any upgrade you endeavor yourself,,,

 

I think I am running one of the first generation FiTech. The “Classic”.

Don’t get me wrong. It does work and work, nicely. It beats my carb, hands down.

I would just prefer less clutter under my hood and I do think the clacking of the injectors and the IAC (that honestly is noisiest the first few minutes) probably was overcome with subsequent generations.

That Edelbrock ProFlo fuel sump pump is definitely not happy in its location.

Today I did connect the FiTech directly to the battery. I hope that will tighten things even more.

 

I didn't look through the instructions of that sump, but if there's a float that shuts off the inlet then that's the problem. There should just be a restriction at most so fuel can circulate back to the tank. FiTech had the same problems with their sump. Open the sump and rip the float and related parts out and try it without. The fuel will circulate back to the tank and keep it cool enough it doesn't boil.

Once you get the in-tank pump that'll fix it well.

As for your EFI, can't you cleverly route the wires and such to hide them? I didn't think any of the FiTech stuff has really changed much in the design or wiring.

Your existing steel line will easily take the pressure as long as it's in decent shape, by that I mean no heavy rust more or less. That steel line would easily take brake or power steering pressures which are way over 1000 PSI so 58 PSI is nothing for it to handle.

 

There are two floats in there. I plan to replace it with the in-tank solution above. Best not to crack open the Edelbrock unit if I plan the flog it on eBay.

As for concealing the wiring (once the pump is in the tank) I’ll give it a shot. Getting the pump in the tank should make a good difference.

 

Hello there Dorian!

My system is very quiet and I don't hear any clicking or any whistling which have been mentioned by other users of the Holley Sniper. But I do have a serious hearing loss requiring hearing aids. I asked Chris about the noise and he said the noises like whistling is caused by the base gasket. I am using two base gaskets and have no noise other than the popping sound of the 12.25-1 compression coming out the back.

It would probably be a good idea to run the Ground wire directly to the Battery. I took a pair of 10 gauge wires and twisted them tight and then ran them through the firewall and down the center console and to the battery compartment. The wires that are the worst for making noise will be the plug wires or the wires that power the coil. I ran the Blue wire to the Fuel pump Positive connection and the negative back to the battery as well. They give you a really nice weatherproof connector for the battery power and the signal from the fuel level sender. My fuel gauge works perfectly with the new sending unit, seems Holley Got it right!

The FITech units are good looking systems but I have heard of people trying to get technical help. The folks I bought mine from made the point that Holley specializes in Fuel systems and have been doing it for a while. The Sniper on my Corvette looks like a Carburetor unless you notice the CTS on my Edlebrock Dual Plane RPM Air Gap intake manifold. The wiring comes out the rear of the throttle body and is easy to conceal. My O2 is under the passengers feet as I had a hard time finding a good place for the O2 to be located in. It has to be 10" from the collector and have at least 18" before the end of the exhaust system is what Holley recommended as if it is not exactly in the right place it might bot see the complete air/fuel ratio and give you mixed results. Had I not purchased the Holley Sniper it was going to be the EdleBrock "Pro-Flow" system with a complete intake and throttle body giving you Multi-port fuel injection with everything but the 8 injectors you would need to complete the system. That would look to much like a modern Car so I chose the Sniper and getting the service I would ultimately need instead.

I like the fact you can use a Nitrous system (Wet or Dry and/or Progressive) with the built in features of the Sniper. For the extra Hundred Bucks they will sell you the Super Sniper which can handle forced induction.

Do you still have a mechanical Tach on your Corvette? My Corvette came with a factory Transistorized Ignition system and the mechanical tach on the distributor. When I got the T.I. system overhauled I boxed it up along with the coil and the original distributor. The MSD distributor I have has the mechanical tach drive built into it. The folks at EFISystemPro don't really like the MSD distributor unless you lock out the advance and remove the advance mechanism. I bought the parts to lock my distributor out and make it work with the Sniper Ignition system requirements.
If you are seriously thinking about going this direction then you might download the 76 pages of instructions and take a look at the requirements and features. They also have a short installation guide as well as wiring tips on the website for either Holley or EFISystemPro. After studying the guides I was convinced that this was the system I wanted. The Sniper Software for the PC is incredible and has a lot of features that you will learn to use.
In my case since I have to pump the water/methanol into the engine while under a load the Sniper allows you to use two separate fuel systems. They can be activated in several ways including vacuum signals so I will set the system up to spray the water mixture when under loads when the engine needs the most help. The mixture injected will make the fuel equivalent to 115 octane using windshield washer fluid. It will only spray after the engine is fully warmed up and only when under a load as set by me.

I am very anxious to get my system to control the ignition as well as fueling. With timing control the Sniper will adjust the timing and fueling allowing it a better idle speed control. The A/F ratio stays very close to where I set it and the exhaust no longer smells rich like it used to. I love the little hand held screen they use with this system, it is handy and comes with a cover that you can mount in your Corvette allowing you to see what is going on or if you prefer you can hide it and make them think it is a carburetor as you don't use it for much after setup. As I mentioned before I purchased the Holley CAN bus adapter to allow laptop to be used inside the car while driving.

I will try some pictures online, I hope they work....

Stay Healthy Dorian!