Opinions on going EFI

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Carb camp here too. I did have the Street Avenger carb and like Stanglover, I had to modify it but I couldn’t get it run that great. I thought about an efi system but too much money for me. So I got a Quick Fuel carb and I have it dialed in perfect. Very responsive and my car runs and starts great! Anyway, that’s what I did and I’m very happy. Hope whatever you decide to do works out the way you want. Good luck!
 
Carb camp here too. I did have the Street Avenger carb and like Stanglover, I had to modify it but I couldn’t get it run that great. I thought about an efi system but too much money for me. So I got a Quick Fuel carb and I have it dialed in perfect. Very responsive and my car runs and starts great! Anyway, that’s what I did and I’m very happy. Hope whatever you decide to do works out the way you want. Good luck!
TY, more great feedback right there. The 670 is my brother’s anyways on loan for life if needed, and it was used when we put it on. Like I said earlier, Oshkosh is 2 hours away and after 6 mons he wanted it out of his shop more than I wanted her back on the road after my nightmare with the cam so we just never dinked with it enough as Stanglover did, which sounds like great advice as his initial issues sound exactly like my current state. My local shop guy is a fan of the QF carb for the 4V and I am more than happy to give that carb whirl.
 
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TY, more great feedback right there. The 670 is my brother’s anyways on loan for life if needed, and it was used when we put it on. Like I said earlier, Oshkosh is 2 hours away and he wanted it out of his shop almost as much as I wanted her back on the road after my nightmare with the cam so we just never dinked with it enough as Stanglover did, which sounds like great advice as his initial issues sound exactly like my current state. My local shop guy is a fan of the QF carb for the 4V and I am more than happy to give that carb whirl.
I was looking at a QF 735cfm, but when Holley took over, the 735 disappeared from the line up. Or at least I believe it was about that time. The QF carbs were started by some former Holley engineers who got it right. That's the story I was told, so maybe, maybe not.
My "guru" guy thought a 750 was a bit too much carb for a 351C. From the reading I get, I tend to agree.
 
I was looking at a QF 735cfm, but when Holley took over, the 735 disappeared from the line up. Or at least I believe it was about that time. The QF carbs were started by some former Holley engineers who got it right. That's the story I was told, so maybe, maybe not.
My "guru" guy thought a 750 was a bit too much carb for a 351C. From the reading I get, I tend to agree.
My guy believes they make a 700 but I haven’t researched too much yet. I didn’t mention this in my earlier posts but we did put on his 750 holley for a two week test in Sept and the engine liked it at as did I when it got past that initial “burp” the 670 also has. Maybe she needs a tweener with my arrangement between engine/trans/gears. Just strange and a good problem to have as so many others on here are working hard to get to at least to where I’m at.
I’m also extremely thankful he’s a cool straight shooter and was thinking of me when he figured out it was the fuel plumbing in the 68. Hope I can call him a “step-brother” by this next summer!
 
My guy believes they make a 700 but I haven’t researched too much yet. I didn’t mention this in my earlier posts but we did put on his 750 holley for a two week test in Sept and the engine liked it at as did I when it got past that initial “burp” the 670 also has. Maybe she needs a tweener with my arrangement between engine/trans/gears. Just strange and a good problem to have as so many others on here are working hard to get to at least to where I’m at.
I’m also extremely thankful he’s a cool straight shooter and was thinking of me when he figured out it was the fuel plumbing in the 68. Hope I can call him a “step-brother” by this next summer!
It sounds like we have similar engines. Mine's good for (on paper, haven't dyno'd) around 406hp (based on CompCams CamQuest application when selecting my cam and noting everything I'd done to the engine). My Edelbrock Performer 1406 (600 cfm) does an excellent job of feeding it - no hiccups, burps, or otherwise. I don't know that I'm getting all I can out of mine, but for trips to car shows and occasional spirited driving, it's perfect.
 
I guess I’m not against either fuel system. But for me, I purposely sought out a stock Ford EFI system from an earlier model year, mostly for the very high reliability of those systems. So, I am going Speed Density for now, but a Mass Air is an easy conversion with a stock computer.

Have/had cars with both. For me, zero FI issues, some carb issues. I know we mostly hear about the problems folks have with these aftermarket EFI systems, but I’ve not been able to track down the statistics of these on cars. People keep buying them, so there must be a high acceptance rate, or the belief there is. And someone said there is no such thing as a bolt-on carb; that’s the truth, which I think makes EFI something anyone can do (look at me, first time EFI swap and had no codes on the initial runs). I think that goes to the reliability of this fueling approach.

Kinda reminds me of the Apple vs Microsoft debate; one highly customizable and one take it or leave it. I think that fits.
 
My guy believes they make a 700 but I haven’t researched too much yet. I didn’t mention this in my earlier posts but we did put on his 750 holley for a two week test in Sept and the engine liked it at as did I when it got past that initial “burp” the 670 also has. Maybe she needs a tweener with my arrangement between engine/trans/gears. Just strange and a good problem to have as so many others on here are working hard to get to at least to where I’m at.
I’m also extremely thankful he’s a cool straight shooter and was thinking of me when he figured out it was the fuel plumbing in the 68. Hope I can call him a “step-brother” by this next summer!
If there's a 700 in the works, that might be a good addition between a 670 and a 750. Also the jetting might be a better balance.
Just to recap on my carb. I had also tried different pump cams and pump volume as well as vacuum location, ported versus manifold. I ended up with ported vacuum, stock cam and pump volume and the 6.5 power valve that was in the 670. The main changes were drilling the front of the primary plates and swapping out the squirter from a 31 to a 35. This is with a Melling MTF2 stockish cam that gives 17" vac on a gauge. By that number an 8.5 power valve ought to have worked, but it was worse, far worse. So, basically this out of the box carb wasn't too far off. It just needed more air at idle and a bigger squirt to get it going.
Timing of course is a big contributor to overall performance and that too took a while to figure out with a stock Autolite distributor.
 
My .02.....
I'm running the FI TECH EFI Classic model, the one that looks like a holley carburetor. Its good for 600 horspower and the computer is seperate from the throttle body. I like knowing I can mount it away from electrical stuff and away from heat. They also use OEM sensors/parts (injectors, o2 etc....) so if it were to crap out it could be repaired with parts from a local auto parts store. This is my 2nd fitech system and they work well for me. Just spend the time on the installation.
 
My .02.....
I'm running the FI TECH EFI Classic model, the one that looks like a holley carburetor. Its good for 600 horspower and the computer is seperate from the throttle body. I like knowing I can mount it away from electrical stuff and away from heat. They also use OEM sensors/parts (injectors, o2 etc....) so if it were to crap out it could be repaired with parts from a local auto parts store. This is my 2nd fitech system and they work well for me. Just spend the time on the installation.
A note about parts. Most of the FiTech parts are GM parts. It is a good idea to research the part numbers for replacement parts and carry those p/n in the car just in case.
 
As most everyone has mentioned there are pros and cons to both sides. I was a diehard carb person and even felt a little guilty about thinking of switching over to efi, but after sitting down and really thinking about what I wanted from my engine I decided to make the switch and went with a Holley Sniper and their Hyperspark distributor.

To me, the deciding factors were easier starting, better fuel mileage, electronic control of the timing and on the fly adjustments plus real time read out and a log of the engine overall performance - rpm, temperature, o2, fuel burn, timing, and a lot more. You can also set high and low limit triggers for things like over rev, engine temp, throttle position and various other to protect your engine. And there are some auxiliary outputs to use, such as if you are running electric fans or have a/c.

Yes, like anything else there are failures out of the box and other issues that you might run into during your install but to me the rewards were worth the risk. As a lot of people have mentioned, RI can be one of the biggest issues on efi's and yet it's the simplest to avoid if you follow the instructions and do it right.

Cold weather and a carb equal hard start. With my old Holley 850 dp I would have to pump the pedal, crank and repeat until I got it running. Do I miss the old school of not having a carb - not really. Attach is video I just took for this post.

View attachment 2 Month First Start.mp4
 
As most everyone has mentioned there are pros and cons to both sides. I was a diehard carb person and even felt a little guilty about thinking of switching over to efi, but after sitting down and really thinking about what I wanted from my engine I decided to make the switch and went with a Holley Sniper and their Hyperspark distributor.

To me, the deciding factors were easier starting, better fuel mileage, electronic control of the timing and on the fly adjustments plus real time read out and a log of the engine overall performance - rpm, temperature, o2, fuel burn, timing, and a lot more. You can also set high and low limit triggers for things like over rev, engine temp, throttle position and various other to protect your engine. And there are some auxiliary outputs to use, such as if you are running electric fans or have a/c.

Yes, like anything else there are failures out of the box and other issues that you might run into during your install but to me the rewards were worth the risk. As a lot of people have mentioned, RI can be one of the biggest issues on efi's and yet it's the simplest to avoid if you follow the instructions and do it right.

Cold weather and a carb equal hard start. With my old Holley 850 dp I would have to pump the pedal, crank and repeat until I got it running. Do I miss the old school of not having a carb - not really. Attach is video I just took for this post.

View attachment 70991
Nice car, nice sounding and nice starting.
I have to admit, mine doesn't start that easy after sitting for a long period without squirting fuel down the vent tube.
 
The FiTech EFI classic seems to be a step in the right direction with it's separate ECM and OEM replaceable sensors.
The only thing that I don't see, is what are it's tuning capabilities as compared to the other manufacturers ?
Still dealing with my buddy's 2 x 4 sniper system that has run extremely well at times, but issues with injector harness and or injectors again, seems this time the issue may be contained in the front (slave) throttle body as the front cylinders run lean and the rear cylinders run rich.
He got about a month and a half of running very well since both throttle body's came back from Holley.
3 year warranty on the FiTech system is also a plus, as long as it's not out for warranty all the time.
Boilermaster
 
As most everyone has mentioned there are pros and cons to both sides. I was a diehard carb person and even felt a little guilty about thinking of switching over to efi, but after sitting down and really thinking about what I wanted from my engine I decided to make the switch and went with a Holley Sniper and their Hyperspark distributor.

To me, the deciding factors were easier starting, better fuel mileage, electronic control of the timing and on the fly adjustments plus real time read out and a log of the engine overall performance - rpm, temperature, o2, fuel burn, timing, and a lot more. You can also set high and low limit triggers for things like over rev, engine temp, throttle position and various other to protect your engine. And there are some auxiliary outputs to use, such as if you are running electric fans or have a/c.

Yes, like anything else there are failures out of the box and other issues that you might run into during your install but to me the rewards were worth the risk. As a lot of people have mentioned, RI can be one of the biggest issues on efi's and yet it's the simplest to avoid if you follow the instructions and do it right.

Cold weather and a carb equal hard start. With my old Holley 850 dp I would have to pump the pedal, crank and repeat until I got it running. Do I miss the old school of not having a carb - not really. Attach is video I just took for this post.

View attachment 70991
Kilgon,
Thank you for posting that. I still have good results in opening the hood, checking oil and radiator levels, giving her the eyeball check and then cracking the throttle with 1 1/2 pulls and she starts. Yes, depending on weather her in WI., I may have to adjust the tension on the E-choke housing. I am not concerned about fuel mileage, only the off the line throttle response that I’m trying to figure out. Thanks again!
 
Hi

Ive been running the Holey Terminator X TBI for 3 years, runs great. Easy installation and looks just like a carb. With the dualsync dizzy its a good combo.
 
Yes, depending on weather her in WI., I may have to adjust the tension on the E-choke housing. I am not concerned about fuel mileage, only the off the line throttle response that I’m trying to figure out. Thanks again!
I too have had a bit of an issue figuring out the best choke setting. As I don't drive too much when it's cold, other than early spring or late fall, I set it for summer temps. That does cause some issues when it's colder, but just means I need to let it warm up longer. I'd wait till summer now to play with that setting unless you have a nice warm garage to play in! If you don't have the Holley manual for the 670, you can get it online from Holley. It will help with spring choice and other choke settings.
For the "off the line bog", change the squirter. (That's not what it's called and the Holley manual doesn't describe it, but you know what I mean). As I said, I'm pretty sure I went from the stock #31 to a #35. This will increase the amount of fuel "squirted" down the throat when you hit the pedal. I got my Holley parts from a local speed shop. The only time I do get any bogging is when the engine is not up to temp and that I think is to be expected.
Try that before other major changes. You may need to try different ones depending on your motor build.
 
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Back in the 70s and 80s I worked as a tech at a Ford dealership in SoCal. I specialized in TuneUp, electrical, electronic & electronic engine control, emission control, turbocharging systems. I was in that initial generation that watched=, and worked with, the transition from points and condenser electrical ignition, to electronic ignition, to electronic engine control (computerized EEC I and EEC II), and the Variable Venturi 2700 & 7200 carburetors.

Although I felt Ford could have done a better job with the earlier versions of Electronic Ignition and Electronic Engine control with on board diagnostics and memory, which they finally migrated to, all in all I was a fan of the new solutions. When the systems worked well they worked really well. But, when there was a problem, especially an intermittent problem, things could become a nightmare really fast. The "special testing equipment" Ford required dealers to purchase were a bit too far on the side of worthless for troubleshooting an intermittent problem. Back then Ford said diagnostic time was included in component replacement time, and it was not unusual for me to end up tracing down the cause of an issue for a few hours only to be paid 0.4 hours, 24 minutes) for the repair to a bad wiring problem caused a wire not being properly seated into a connector that was buried up inside the instrument panel. Or 0.5 of an hour to replace an ignition module that was failing intermittently, where the problem could only be duplicated after driving the car for at least 25 minutes (and the replacement being verified as having corrected the problem with another half hour or more of driving. We had no portable plug-in OBD1/OBD2 testers, and our analog scopes were large, bulky systems that were not able to be connected to a vehicle while going out for a shake-down or confirmation road test. I had ways I devised to use our large scopes to diagnose various EEC component electrical signals, but back then that was a "black art" and quite frustratingly frowned upon by our factory reps as they told our dealer and service manager that we should be using authorized ways of diagnosing problems, as opposed to our "hack approach" in diagnosing and fixing problems. Therefore, because I was not using the all but worthless authorized equipment they would not pay "M Time" for the time it took to track down and repair unusual situations. As I understand it, a lot of the warranty cost containment approaches to minimize labor time, even clearly legitimate labor time, billings have been largely corrected via various state labor board oversight, the manufacturers still have their labor costs for warranty repairs by having technicians subsidize the labor costs via inadequate labor operation time allowances for the many OpCodes used in billing for labor efforts. The difference in Labor Time Allowances can be significant, and back in the day a swing of 25% or more reduction of Labor Time Allowances between the factory Labor Time Guide and the non-factory Labor Time Guides was not unusual.

So what does this to do with carb vs EFI? Well, despite the advances in the ability to diagnose many computerized issues with OBD1/OBD2 memory and Trouble Codes, many folks in the repair industry will be quick to say that although being helpful, sometimes it takes more than scanning trouble codes to get to the root of a problem. And, even with our portable digital scopes that can be used to test circuits on the fly while driving, often those experiences can still be very time consuming. When I look at the aftermarket EFI systems I often wonder if they have ODB2 scanning capability, or at least the various wave form patterns for their various devices so one can use a modern digital scope to track down a problem. I am willing to let the folks more in touch with those diagnostic issues to chime in as I have never installed or worked on an aftermarket EFI system. But, unless and until I begin to hear how modern equipment can be used in a practical way to diagnose aftermarket EFI system problems I will be sticking to the conventional carburetor, and even electrical old school ignition systems.

The reality for me is that I do not race our 49+ year old pony cars, on the track or on the street. Sure, I enjoy blowing out the carbon once in a while, and do not drive then like an old granny might. It is rare I spin an engine higher than 5,000 RPM, largely because all of our engines are original built, not rebuilt, and despite being in good condition I am not looking to start trouble by floating their valves at sustained high RPMs. Also, when it comes to outright performance it has been shown time and again that fuel injection, much EFI, does not provide any kind of significant horsepower improvement unto itself. Even electronic ignition will not provide more power unto itself. It takes a very involved, well tuned, set of systems and sub-systems for a computerized engine control system to bring fourth performance, much less fuel mileage, benefit. And, I, for one, am not inclined to swap in an EFI system, even with an electronic ignition sub-system, into an older, first generation pony car - especially when there are concerns for how challenging these systems are to troubleshoot. Much less the viability to work with the manufacturer with a repair process, especially a warranty procedure. Removing the components and shipping them to a manufacturer so they can "look at it" within a few weeks is not my idea of a good time. Especially if a manufacturer comes back with a "No Problem Found" response. I have been burned a few times too many by oem manufacturers to be willing to subject myself to a similar situation with aftermarket manufacturers' EFI solutions. They are so quick to point out how easy it is to install their systems (it is never as easy as they claim), and tout their support (try getting parts for their older, now outdated systems some time, good luck), and how easy it is to troubleshoot a problem if one is to occur (they are computerized after all!). I do not trust the phookers. When I read some of the horror stories about folks who have run into a problem with their system, especially a model system that is no longer being sold or supported, I just become all the more entrenched into my position of not introducing a modern EFI, or even electronic ignition system, to a vehicle that is running perfectly well using old school systems and solutions. There simply is not enough margin in it for me.

Now, there is one significant consideration that may cause me to sway my opinion on the matter. If a person has an older vehicle, say a work truck, that has not been replaced with a newer, modern truck, that is used to go between higher and lower altitudes constantly - that kind of situation would benefit from a system that alters the air/fuel ratio between the higher and lower altitudes. But, even then I would be asking why the older truck is still being used like that.

All that said, for those who prefer to lean toward the aftermarket EFI and electronic ignition systems, so be it. I will never gripe about your choice to do so. When you run into a problem with the system(s), especially if your new system is more than a few short years old, be prepared to get some schooling. Lest anyone feel I am taking my position because I fear newer technology, please keep in mind that I lived through the Years of Transition in the 70s and 80s. I do trust the technology when things are working well. It is more that I do not trust the manufacturers (oem or aftermarket) to do what is right when things do go wrong. I do not like being the one to end up grabbing the dirty end of a stick when a problem comes up - especially when it is a totally avoidable problem.
 
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I have never had a fuel injected vintage vehicle. My other cars all have Holley or Edelbrock carbs. The Edelbrock carbs have never seemed right. I have tried to set them up but have never quite got them right myself. I have sent my Chevelle to two different Edelbrock "experts" only to have them run worse than how I had them set up. I switch that car to a Holley and it is usually okay but still cold start ups are not awesome. And all of them are long crank and pumps required after sitting for a while. I have been told by my engine builder the only way to get the drivability I prefer is to go EFI. He recommends the Holley Sniper system and I have asked around my circle of friends and found three guys who are running Snipers. Two are on big block Chevys and one is on a Ford 302 so no first hand Cleveland experiences so far. All three of these guys love the Sniper and have had no problems with them and they have all been running them for three or four years. I am waiting for my Aeromotive fuel tank to come of back order and then be installed. After that, I will be pulling the trigger on a fuel delivery system. I am planning on the Super Sniper system because I am told that the Super Sniper advances and retards the ignition timing as necessary, when the distributor is connected. One of my best friends since high school is planning a Sniper upgrade this spring for his Camaro. He is the guy that researches everything to death and he is convinced that it is the right EFI for him. I am wondering if anyone has installed a Sniper on to a Cleveland and tied in the distributor and if they have had encountered a lot of issues or if it was pretty smooth.
 
Well, I decided to back out on the EFI this week. I was on the fence as to whether I wanted the added expense and the trip outside my comfort zone in the first place. On Tuesday I found out my Aeromotive fuel tank is still on back order and now has no promise date. I took this as a sign that the EFI thing just isn't meant to be. I am going with conventional fuel tank, mechanical fuel pump and 650 double pumper carb. These are all things I know and am able to diagnose and repair as necessary. The 650 double pumper is the carb that the engine was dyno'd with, so I know how that will perform. The fuel injection is above my skill level and would have been a stretch for me to get wired correctly and up and running properly. I guess you could say I chickened out, I just think I am capable of getting the old school system installed and up and running, and not sure of my ability to figure out the EFI.
 
Here is my EFI journey, so far....

I bought a Fitech EFI back in 2015 and eventually put on my 351C 4V engine which is what I would say is a mild build. The biggest advantage was definitely the cold starts. It ran best when the engine was cold. I had alot of minor nagging issues with the unit after it warmed up. The biggest was a lean bog on throttle tip-in that I just couldn't figure out. I did have it setup for ignition control with an MSD 6AL box and MSD distributor. I eventually got tired of troubleshooting it and the lack of tools that the Fitech offered for figuring out problems. The Snipers were not on the market back when I bought it so that wasn't a choice back then. I eventually decided to sell the Fitech and got most of the initial investment back out of it. I was all set to go with a Sniper system until I had a change of heart and decided to try a good carb instead. I had Brent Lykins spec a custom carb for my build (he also supplied the roller cam for the engine) and I have been pleased with it since its been on the car. Sure the cold starts are not as good but I believe if I spent some time tuning the choke it could be better. Of course I live in north Alabama so it doesn't really get that cold here and its kept inside too.

I believe if someone puts together a good fuel delivery system with an electric pump the cold starts will be much improved over the stock setup regardless of what you have (EFI or carb). I have a new gas tank with an in tank pump. I have a return style pressure regulator to get the pressure down for the carb. Putting that in was alot of work and cost and was done primarily for the EFI but it works very well with the carb too.

I may go back to the EFI one day and have left everything in place for it if I do. Looking back on it I am glad I tried the carb route, especially with the material shortages in the world today.
 
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