Edelbrock Pro-Flo 4 Fuel injection on the Chevelle

Today we make a massive upgrade to the 1965 Malibu SS by installing Fuel Injection to the small block Chevy 350. We will be using a high pressure fuel pump mounted near the tank, a copper nickel pressure supply line, pre and post pump fuel filters and a return line back to the gas tank.
If you have a project you would like to showcase at the end of one of my videos just email me a few pics and a short description to: [e-mail]

[@lazyhoundracing9621]

Nice work Mark. I'm a carburetor guy but I see the beauty of fuel injection for a street car or daily driver. I like how they say plug and play like there is nothing else to do. Thank you for your time.

[@FoothillPaintandFabrication]

Thanks. I know a few carb guys that scoff at fuel injection but they sure like it on their daily driver. This system is supposed to be able to go up to about 950 hp with bigger injectors.

[@lazyhoundracing9621]

@@FoothillPaintandFabrication I have nothing against EFI. Other than my 67 Cadillac hearse and my 53 race truck all my vehicles are fuel injected.

[@FoothillPaintandFabrication]

@@lazyhoundracing9621 Hearse? Do you have a side job I don't know about???

[@lazyhoundracing9621]

@@FoothillPaintandFabrication About 30 years ago I was building an addition on a nursing home and the engine blew up in my work truck. I bought the hearse for $500 to use as a work truck while I rebuilt the engine. It's roomy. I fell in love with it and couldn't let it go. The director of the nursing home was not impressed and made me use the back gate. I load it up with zombies on Halloween and hit the haunted houses.

[@FoothillPaintandFabrication]

@@lazyhoundracing9621 That is awesome!

[@toughflyer]

Fantastic work and a little tip. When you cut your braided line wrap it tightly with masking tape. Make your cut in the center of the tape and remove the tape, perfect cut everytime with no burrs

[@FoothillPaintandFabrication]

Thank you and thanks for the tip. Braided is a pain sometimes, especially trying to get the nut over the end and wires keep popping out.

[@toughflyer]

@@FoothillPaintandFabrication ya the tape will kee the braids nice and tight from fraying out….. makes it a bit easier….. I was a former hydraulics guy on USMC aircraft and that’s always what we used

[@stevebeard3527]

Hi Mark, nice to see the 65 again. I plan on using efi on my El Camino. Thanks for including the “stumbling blocks” in the video. Great job as usual.

[@FoothillPaintandFabrication]

Thanks Steve. If any trouble comes up on the system I will let you know.

[@justinlinville5812]

Always enjoy when the Chevelle is on the channel!!!

[@FoothillPaintandFabrication]

Nice change of pace for sure. John wants it painted red but I am busy with Ruby and he needs to save lots of 💰

[@Hydrogenblonde]

The problem with using vapour lines and short circuiting the fuel return back into the fuel pick-up line is heat. In a cold place chances of a problem are very slim it will probably be ok. In a warm place like Texas or New Mexico, maybe California or Florida, you may get the hot fuel returning from the engine bay flashing off into vapour when it goes into the low pressure of the suction side of the fuel pump. That is why they recommend putting in a return line as big as the main fuel line back to the tank. It allows the hot fuel in the return line to get dumped back into the tank and the large volume of the tank gives plenty of time for the hot fuel to cool before being picked up again. If you don't want to drill the tank to put in a direct return line (and who does?) you can remove the fuel level sender and add a tube to it for fuel return. I must say the fuel and return lines are as important as the injectors and the manifold and throttle body. Skimp on them at your own peril. Keep an eye on the fuel pressure in hot weather with your set up. Best wishes. Ps: if your fuel pick-up tube in the tank has the original filter sock on it remove it. Those original suction filters can not flow the amount of fuel your electric pump will move and they will collapse causing fuel starvation.

[@FoothillPaintandFabrication]

Thanks for the tips. The car ran great this last summer in stop and go traffic and it gets over a hundred here all summer. Since the return line runs along the frame away from a heat source it has a fair distance to cool on the way back from the engine bay to the tank in the metal line. Fuel can boil when going from a hot state under pressure to a lower pressure which is not occurring here since return line pressure cannot exceed the pumps capacity to pump since it created the pressure in the first place. Expansion of the liquid fuel is negligible in this situation. I did a wide open hose test into a fuel can before hooking everything up and the flow was strong and steady and with little 46 lb injectors volume should not be an issue. I did message back and forth with a couple of guys that did what you suggested with the sender plater and one had a lot of problems with aeration of the fuel. Took him some time to figure out the problem but he solved it by putting a 90 degree bend in the return line so the fuel returned at the bottom of the tank pointing away from the pick up. So far so good but if it ever has a problem I know where to look. The car runs great with the EFI with perfect cold and hot starting, awesome idle and zero flat spots.

[@Hydrogenblonde]

@FoothillPaintandFabrication yes, if you have ever put up with a car with bad starting, shocking idle and general rough running it is a real eye opener to see how fuel injection can transform a cranky bad running car into a real user friendly gem. I have installed a few EFI systems and the cars involved have been like completely different cars afterwards. I sold one of the cars I fitted a Edelbrock system to and the new buyer said he planned to change the car back to the original inlet manifold and the two barrel carb. I told him to be prepared for a huge disappointment. That car was barely drivable with the two barrel. The cars I fitted the EFI to I also fitted a fuel pressure gauge on the dash. I found that if you can check the fuel pressure immediately on feeling or noticing any unusual running it makes it easier to understand if fuel starvation or vapour lock or pump cavitation may be occurring. Best of luck with your EFI.

[@larrywarner9314]

Just add a return line directly to the tank , thats the rite way to do it , !!!!

[@davegerrard6857]

Yes that is the correct way to do it for multiple reasons!

[@MoBettaLedbetter]

I am researching this same system for my 68 GTO! Love the video and all the info. So you just ran the return line from the regulator to the T fit and back into the fuel supply system?

[@FoothillPaintandFabrication]

Thanks. Yes I Teed in the return line just in front of the fuel pump on the suction side. It has been working great for months now with zero issues. I have been told by some I did it all wrong and I should have removed the tank and added a return line fitting because my way will not work. You are just returning unused fuel at lower pressure back to the suction side for the pump to use again, Seems to work just fine. I do agree in a "perfect" set up a dedicated return line into the tank with a tube that returns the fuel to the bottom so as to not aerate the fuel would be the best but there was not unlimited money on this install.

[@MoBettaLedbetter]

@ thanks so much! I believe I will try your method out when I get around to doing this project. What did you do with the original return line? Remove it or just cap it off?

[@FoothillPaintandFabrication]

@@MoBettaLedbetter There is no return line on any carbureted car, there is a vent line in the back for the fuel tank. I just left it be and ran my own return line. Edlebrock has a return line kit that is a flexible hose set up but I ran a hard line instead.

[@toughflyer]

Btw can you state what pump you used for this? Thanks !

[@FoothillPaintandFabrication]

Walbro GSL392 Here is a link to summit www.summitracing.com/parts/vpn-gsl392bx

[@toughflyer]

@ perfect thank you and if I may can I ask what regulator you went with? Thanks again

[@FoothillPaintandFabrication]

@@toughflyer Sure. I used the Edelbrock regulator that attaches to the end of the fuel rail. I believe it is set to 45 psi and is a return style made for the EFI system.

[@toughflyer]

@@FoothillPaintandFabrication perefect thank you for the video and replies!

[@nlg062701]

I'd like to know what kind of performance improvement you got after the install.

[@FoothillPaintandFabrication]

@@nlg062701 The car hasn't gotten a ton of miles since the install but so far: Excellent cold and hot starts, very smooth power curve with zero flat spots or stumbles. When I test drove the car letting out the clutch from a dead stop without touching the gas it does way better than the carb. No milage numbers yet but the 1967 Chevelle I installed the same system on supposedly is getting 18 mpg on the highway with overdrive. There are several articles out there where dyno tests were performed and the EFI did better than the carb but not by much. I think driveability, tunability and reliability is this systems strong points

[@ryanjohnson8821]

Great video. I just ordered the ProFlo 4 for my ‘70 Chevelle SS 396 project. I already have a Tanks Inc. gas tank with an in tank fuel pump. Hopefully that will help me avoid some of the issues you ran into. Also, I’m replacing the factory 1/4” return line with a 3/8” line to match the feed line. I was wondering can you run the fuel lines to the back of the intake for a cleaner look.

[@FoothillPaintandFabrication]

Hi Ryan and thanks. Yes you can easily swap the cross over line from the back to the front and put your pressure in and regulator out in the back. The Edelbrock regulator works well but may pose a space problem at the back of the fuel rail. A remote regulator would work just as well too. The larger return line is a good idea. I had a problem with a 67 Chevelle I installed this system on because the vibration dampener had shifted over all those years so the timing mark was way off so when I set the ignition timing to 12 degrees before top dead center it was very retarded badly. So bad that the exhaust manifolds ran cherry red at idle. Ended up cooking a brand new set of plug wires before I figured out what the problem was. If you are running your original dampener confirm the timing mark has not moved. Good luck on your build and let me know if you have any questions.

[@ryanjohnson8821]

@@FoothillPaintandFabrication thanks for the advice. The install doesn’t seem as daunting after your video. I still have a ways to go to get started on the install though. Got to get the frame painted and the body back on first

[@M3nttitta]

Hi, I have a question, I'm in the process of converting my Vrotec 5.7 to EFI Pro Flo 4, I'm not sure if it's necessary to use a pump in the tank and another one in the middle. Please help me.

[@FoothillPaintandFabrication]

From what I am seeing on the specs for a 5.3 in tank fuel pump they produce 30 gph at 60 psi. The Pro Flo 4 looks like it wants 60 psi but needs about 57 gph so your stock fuel pump does not have enough gph. It might work with the small injector's but it would be pushing it. Walbro makes in tank pumps you could convert yours to which is the route I would go instead of adding an additional inline pump, more wiring and addition failure point.

[@M3nttitta]

@ Hello, thank you very much for your reply. I bought the Fitech 50001 kit, it includes hoses, unions and an inline pump. Are you telling me that I can simply change my original pump and skip the additional pump in the line? My other question is the following: since my current pump is less than 60psi, if I install this second pump in the line (with a higher flow rate) to work in conjunction with the old factory pump, will it work correctly? Or does the pond pump necessarily have to be of the same flow rate? Thank you very much for your reply.

[@FoothillPaintandFabrication]

@@M3nttitta I don't know what the Fitech system wants as far as psi and gph. If you have an in tank pump with a return line (which you should with the Vortec) and it supplies enough psi and gph the fuel injection system could care less if it is inline or in tank fuel pump. Do you know the requirement spec for the Fitech?

[@davidrosenthal735]

Hi Mark, hope you’re doing well. Still working on my 64 Malibu SS here in Florida. Just watched your video on the fuel injection install on the 65 Malibu. You mentioned the electric fuel pump you are using is very quiet. For my carbureted 327 I’m using a Holley 670 with an edelbrock electric pump. This seems to be working well but the pump is a little too loud for my liking. Do you know of one that might be a bit quieter ?

[@FoothillPaintandFabrication]

Noisy fuel pumps are the worst! We used a Walbro inline pump and although you can hear it with the key on and engine off you cannot hear it with the engine running. I did my best to isolate it though. The Edelbrock pump looks a lot like the Walbro unit so I don't know if they are just repackaging theirs and tripling the cost or not. I have been told the Holley pump is crazy load so avoid theirs. How do you have the fuel pump mounted?

[@davidrosenthal735]

I used isolaters between the pump and the frame. I don’t have a return line and that concerns me for longevity of the pump. I agree with what you said though, when the engine is running I can’t hear it so at this time I’ll likely keep it as it is. In your opinion is there really an advantage using an electric pump vs. a mechanical one on a street driven car ?

[@FoothillPaintandFabrication]

@@davidrosenthal735 For non fuel injection cars a mechanical pump is more than sufficient as long as it can keep up with the carburetor. Are you running a fuel regulator?

[@davidrosenthal735]

No, I am not running a fuel pressure regulator. This all got started when I noticed my fuel pressure gauge was showing about 6psi at a cold start. After the engine warmed up the pressure dropped to zero. I changed my mechanical fuel pump at least three times. I decided to install an electrical pump, no change. I put a 1/2” phenolic spacer between the carburetor and the intake still not a fix. After the gauge drops to zero there is no change to the engine, it continues to run fine. So confused.

[@FoothillPaintandFabrication]

@@davidrosenthal735 Very strange. The psi on the electric pump should be much higher. I wonder if the gauge or plumbing to the gauge is faulty. Could be vapor lock but that is unlikely to just start happening but it might be worth a look to see if any fuel lines are too close to a heat source. Is the tank vented well? Has there been a change to anything else prior to this fuel pressure problem?

[@humongouscodger437]

What fuel pump did you use

[@FoothillPaintandFabrication]

Walbro GSL392 Here is a link to summit www.summitracing.com/parts/vpn-gsl392bx

[@jarrettb.7302]

I have the pro Flo 4 app on my phone but under the “E tuner Display” yours has a speedo and tach. Mine only has a tach and it’s just a basic graph style. It doesn’t look like an actual gauge like yours. Are you using the E tuner 4 app? I can view my speed on the transmission app but that one is separate for the trans controller they sell.

[@FoothillPaintandFabrication]

@@jarrettb.7302 Yes I downloaded the newest version I think. When I select the E Tuner display it asks to use my phone's location services so the MPH must get its signal from GPS on the phone. I am using an Android with the latest OS.

[@jarrettb.7302]

@@FoothillPaintandFabrication I see. I’m on iPhone so the android and iPhone apps must be different. Thats pretty unfortunate.

[@FoothillPaintandFabrication]

@@jarrettb.7302 Android wins again! It is a nice feature, maybe they will add it soon.

[@leww2873]

is a msd box still needed?, don’t know about these systems, but I’m thinking about switching over

[@FoothillPaintandFabrication]

They give you some recommendations for a coil but they are nothing special. An MSD box is not needed and the computer handles all spark advance, idle and mixture. Drivability is really nice. Not sure on mileage just yet but it is being watched to see how much it improves.

[@BusyAsABeaver72]

I am planning on getting an aftermarket TBI for the panel truck. After seeing the hassle you went through with the return line I (hopefully) am glad I retrofitted my existing gas tank with an in tank electric pump from Speedway Motors. I'll want to use the braided steel lines so thanks for sharing how to fabricate them. Is that a kit you purchased to make them up? Another excellent video Mark. Thanks

[@FoothillPaintandFabrication]

Thanks Does your in tank pump have a built in regulator to bleed off the extra pressure? Yes we got a kit from Amazon with 6an hose and fittings. If you are planning on running pump gas then there are a ton of options on there with hose and fittings. Here are two links: a.co/d/6fqsGNe a.co/d/84Emqap Throttle body units are a lot less expensive and less work with some nice benefits.

[@BusyAsABeaver72]

No it doesn't. That's my next step to get a regulator (once I have a permanent fender panel to put it on). Thanks so much for the link! I put the black braided hose kit on my Amazon wish list.

[@FoothillPaintandFabrication]

@@BusyAsABeaver72 Ah those pesky details... Getting a good cut without fraying the braid is the tricky part. I walk the cut off wheel around the hose kind of like a pipe cutter so the wheel cuts down into the braid through the black tape.