Opinions on going EFI

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Joined
Jan 2, 2019
Messages
369
Reaction score
325
Location
Wisconsin
My Car
1972 Mustang convertible, 351C 2V with FMX (#'s matching)
Currently equipped with 351C 4V 4BM, .060 over, roller cam, Sanderson block huggers, -AC
I have not been super happy with my performance after I swapped the FT that failed and went to the RR drivetrain. The “best” carb I have ended with last season was the Holley St Avenger 670 with E choke and I also swapped the FMX to a C4 with a 2k convertor.

All summer long she has been Dr J/ Mr H and I constantly chased timing/carb settings/low vac/premium fuel changes, etc.

My local hot rod mech and I were discussing a new issue he found on a 68 stang BB he said was stumbling and acting just like mine and it may be fuel line/pressure/volume related and not the carbs fault so he wanted to figure it out next week and let me know his “learnings”. In spring it will go back to his shop to go from tank sending unit to fuel pump and check the tanks vent line as well to verify I didn’t miss something last year when I went through it all visually. Probably should have changed all the plumbing when she was in the air for 6 months at my brothers shop..
Anyways, we were talking about the game plan and I told him I’m on board with verifying all is good with fuel delivery and will swap out the 670 and give it back to my brother and try a quick fuel but if she is still being bitchy I want to just go Holley EFI and live happily ever after since this block is not the #’s matching 2V that is stored in my brothers shop.

My current set up dynoed with the FT drive train at 408/425 so I’m totally happy with that being a droptop with subframe connection.

I’m all ears on advice for just going to a simple/reliable EFI system and your experiences.

TY
 
I'll follow along here to read the responses. I'm happy with the performance of my 4160 Holley 750cfm but think I'll try EFI in the future. For me it's more about trying something new than any tuning/performance issue.
 
I appreciate your interest!
My local guy knows his stuff as does my brother but Oshkosh is 2 hours north and not easy to go up and experiment on her. I’m a “traditionalist” as is my local guy and l do like the smell of gas in the garage but trying something new is exciting as well. He told me 1k ish to install and agrees with me not needed to go with some exotic system if I pull the trigger so I will look forward to responses as well!
 
I am going with the Holley terminator x stealth. I am using their coil, spark box and dual sync distributor.

since it is a blower motor efi will be easier for me to pull timing out and adjust fuel.

also wanting the ability for my wife to just turn the key and go.
 

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I am going with the Holley terminator x stealth. I am using their coil, spark box and dual sync distributor.

since it is a blower motor efi will be easier for me to pull timing out and adjust fuel.

also wanting the ability for my wife to just turn the key and go.
That’s an interesting set up going blown and I would never consider letting my wife putting her foot on the throttle if that was under my hood!
 
You will get all different opinions here. I am in the EFI camp. I have been running a FiTech for 5+ years. I am very happy with it except for a few quirks. All of the "plug in" EFI systems have their quirks. Btw, although they market them as plug in, they are not.
 
+1 on what Tony said. The bolt on and go self learning EFI is about equivalent to the bolt and go out of the box carburetor. I have never seen either one, both are unicorns, in my opinion. Chuck
 
You will get all different opinions here. I am in the EFI camp. I have been running a FiTech for 5+ years. I am very happy with it except for a few quirks. All of the "plug in" EFI systems have their quirks. Btw, although they market them as plug in, they are not.
Thank you sir. I’m ok with the replumbing for return to tank if needed, etc. I don’t want a “messy” hide the wires deal or a finicky system. Plain jane consistent performance is all I need. Thank you for responding!
 
What puts me off of the EFI systems is when you lookup reports of them not working. Sure, when they work as advertised, they are great. Sometimes they don't work right. With holley, they means you have to literally take the entire unit off your car and mail it in for repairs. Last time I checked, they were running 6 week turn around for repairs. And last time I tried to call holley support, it was over an hour wait on hold on the phone.

You cannot just run to the store to buy spare parts. When the all-in-one EFI system goes down, it has to come off the car as a unit.
I have seen reports of the EFI systems having the ECU crap out. I have seen them stillborn with a bad LCD/handheld programmer right out of the box.
I would say your chances of getting a dud are slim but not impossible. When you do get a dud, your weekend project of swapping to EFI just turned into a 2 month long project.

I had ordered a sniper EFI for my car. I ended up canceling the order based on an alarming number of bad reports.
 
What puts me off of the EFI systems is when you lookup reports of them not working. Sure, when they work as advertised, they are great. Sometimes they don't work right. With holley, they means you have to literally take the entire unit off your car and mail it in for repairs. Last time I checked, they were running 6 week turn around for repairs. And last time I tried to call holley support, it was over an hour wait on hold on the phone.

You cannot just run to the store to buy spare parts. When the all-in-one EFI system goes down, it has to come off the car as a unit.
I have seen reports of the EFI systems having the ECU crap out. I have seen them stillborn with a bad LCD/handheld programmer right out of the box.
I would say your chances of getting a dud are slim but not impossible. When you do get a dud, your weekend project of swapping to EFI just turned into a 2 month long project.

I had ordered a sniper EFI for my car. I ended up canceling the order based on an alarming number of bad reports.
I appreciate your input and sucks to hear your unpleasant experience. This is why I asked about this topic as I’m not ready to give up on getting my baby dialed in with a 670/700/750 cfm and a choke system that works for the midwest seasons. We do however have a Holley rep nearby in the Chicago burbs that is available to my area and it may come down to him and my local speed shop guy having a few pops one day to get me all in to their EFI set-up if I pop smoke on the carb with my engine.
 
The horror stories related to FiTech and Holley escalated after the supply chain issues after COVID. I think these two had some serious issues so it is a crab shoot. I still have my carb and I travel with it when i go in the Hot Rod Power Tour just in case. I have a Robbmc surge pump that works with the mechanical pump so it wont be too hard to switch to carb in an emergency.
 
That’s an interesting set up going blown and I would never consider letting my wife putting her foot on the throttle if that was under my hood!
Well she owns it too. She drives my raptor with no issues. And she is definitely careful to a fault when driving my stuff.
 
The horror stories related to FiTech and Holley escalated after the supply chain issues after COVID. I think these two had some serious issues so it is a crab shoot. I still have my carb and I travel with it when i go in the Hot Rod Power Tour just in case. I have a Robbmc surge pump that works with the mechanical pump so it wont be too hard to switch to carb in an emergency.
Had a good laugh at crab shoot! 😄😄 Thanks!
 
My two cents DAverkamp: I've successfully ran a couple efi set-ups over the years. They are OK and really nothing against 'em. I always go back to carbs though. I was never totally comfortable with the unnecessary complexity of fuel injection on my 1972 Mustang. I personally thought it was a bit out of place on a classic car. Again just my opinion.
 
My two cents DAverkamp: I've successfully ran a couple efi set-ups over the years. They are OK and really nothing against 'em. I always go back to carbs though. I was never totally comfortable with the unnecessary complexity of fuel injection on my 1972 Mustang. I personally thought it was a bit out of place on a classic car. Again just my opinion.
I hear you. That and others experiences so far don’t have my first foot on the fence at this point.
 
Well, I'm in the CARB camp personally. I think that if a person is driving lots and lots of miles per year, there may definitely be an advantage with EFI for slightly better fuel economy. If not, then to me, it's waste of good money and a load of work to put it in.
I run the same Holley S/A 670 on a 71 351C 4V and yes at first it was a problem getting it to run on MY engine without stinking up the garage with gas smell. Holley's tend to run rich out of the "bolt on and go" box and mine was no exception.
What I'm going to add next, has been a source of "discussion" before on the Forum, but I took the car to a custom speed shop nearby and their carb guru drilled a 3/32" hole in the primary throttle plates, reset the transfer slots (I had opened them up to try to get it to idle better) and did other basic tuning tweaks. Now the carb runs without the awful gas smell. I also increased the squirter size from, if I remember, a 31 to a 35 and that eliminated a slight bog when I hit the pedal. I had O2 bungs installed in the exhausts earlier, so I borrowed an AFR gauge and found the reading pretty damn close to optimal. Of course, timing is a key ingredient as well and I found 14 degrees initial, 20 degrees crank plus about 4-6 degrees vacuum gave me a motor that runs smooth, pulls like a train and gives reasonable fuel milage.
That's just my opinion. If EFI is what you want, then don't let me stop you. Your car your way.
Oh and Tony, I don't have to lug around a "spare carb" just in case!
 
A quick study of EMI/RFI should be mandatory for anyone contemplating installing aftermarket fuel injection.
Do you currently have, ,,,, electric cooling fans, high energy ignition, high amp alternator, electric fuel pump, megawatt sound system, high energy starter or transmission that has inputs/ outputs ? , you need to study up on EMI/RFI.
What c9zx said is very true about tuning, there are multiple layers/ tiers of tuning, basic will get you only to the bolt on carb stage, advanced tuning is much better, and laptop tuning is preferred
I you build it and tune it, can you also troubleshoot/diagnose it when you have issues. ?.
These are the things to consider BEFORE one makes that jump.
Boilermaster
 
The horror stories related to FiTech and Holley escalated after the supply chain issues after COVID. I think these two had some serious issues so it is a crab shoot. I still have my carb and I travel with it when i go in the Hot Rod Power Tour just in case. I have a Robbmc surge pump that works with the mechanical pump so it wont be too hard to switch to carb in an emergency.
You've just given me the perfect reason NOT to give away my Edelbrock 1406 4bbl after I get the E-Street TBI installed - Thanks! I've also got a surge pump (Edelbrock) for mine, so the swap back (if necessary) would also not be a big deal.

I'm in the process of installing an Edelbrock Pro Flo 4 MPFI system on my Jeep's AMC 304, and so far, it's pretty awesome. The toughest part for that build has been locating everything because my fenders swing open (makes working on the engine a LOT easier and looks super cool at car shows), which makes it tough to run wiring and plumbing without having to unplug it all when the fenders are opened. When I was researching the options, I found they no longer offered the E-Street TBI system, which was a bummer... so I found the Pro Flo 4. Since the 304 came [to me] with an Edelbrock Performer 304 intake, I was hoping they'd have the Pro Flo for the 351 Cleveland, and I'd use the E-Street on the Jeep instead, but unfortunately that wasn't the case.

I know it's not a 7173 Mustang, but here's where I'm at so far with the Jeep project. Yes, I have new valve covers... just didn't want to scratch them up while finding homes for everything.
IMG_20221030_175214575_HDR.jpg


Had to make a place on the firewall for the surge tank, under the battery tray. It's not as big as I though it would be, but the one for the Mustang will wind up taking the place of the windshield washer reservoir when the time comes.

IMG_20221004_114421720.jpg


Swing-out fenders have been a MAJOR help with this V8 swap. I need to trim the inners a bit since I also went up to 35" tires, but they still work. 4' of piano hinge and a handful of pop-rivets - best $8 I ever spent on my Jeep.

IMG_20220108_170322308_HDR.jpg


The main reason this project is taking so long is because I basically kicked my Jeep in the nuts just so I can have a V8 & automatic. Unfortunately, the donor vehicle was almost as bad as my Mach 1 when I first got it, so I had to restore everything before I could swap it in. The engine, transmission, transfer case, driveshafts, steering column, brake pedal assembly, and engine-side wiring harness were all in desperate need of rehab. The steering column and engine harness were the worst of the lot, but now it's all about fighting the weather since I'm doing it all outside under a carport. That, and I'm pretty much overhauling a ton of stuff, to include the roof and doors, seat frames, carpet, stereo, and the biggest of all, HVAC replacement (plumbing everything while the engine goes together). Once I get the Jeep up and operational again, it'll be time to finally install the E-Street onto the Mustang.

Sorry for the trip down 'Off Topic Lane.'

DAverkamp: I'd definitely recommend a Holley Sniper, if that's what you're looking at. My pal Dave (who received my Jeep's donor vehicle with my old engine and stuff) first went with a Howell, and was extremely disappointed with it. After running the original MC2100 2bbl I'd put on the engine for awhile, he switched to the Holley Sniper and has been very pleased ever since. Hope that helps!
 
EMI/RFI, intentional or unintentional? ;)

Buzzer on!
How often is the buzzer on when driving, though? LOL!

Boilermaster makes an awesome point: the electrical system needs to be up to the task. I know the stock alternator on my Mach 1 will be getting an upgrade before I get the EFI ready for install. I have some of those things he mentioned (electric fuel pump, Duraspark ignition, etc.), and I know the last time I drove the headlights on, I was getting the 'you don't have enough electrical horsepower to be driving at night' indications (you can hear the signal flasher through the speakers, step on the brake pedal and the lights momentarily dim, etc.). And that's just with the electric fuel pump and Duraspark running while driving and having the radio on just loud enough to hear it with the windows down!

I don't know that EMI/RFI would be THAT much of an issue, though. Most of those devices are pretty good about not radiating too much (not like the old non-resistor spark plugs), but our cars having the bare minimum electrical systems (when compared to modern cars running EFI) could wind up highlighting those issues.

Good info here!
 
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