EFI -VS- TBI which one-good-best-better?

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Christine&Rusty

Driver for Wile E Coyote, Genius, CEO ACME Inc.
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I have been looking at fuel injection. I was wondering if anyone has done the DIY on either Edelbrock EFI with the tablet I think it is PN-35900? I have not seen as many for the Holley system, and it seems like it's just a couple sprayer nozzles that would spray down the dual plane Edelbrock intake already on the vehicle. Seems that would be more for economy than any performance.
And I have a brand new never opened Holley 650 cfm spread bore that was the fix for the Edelbrock it has on it now. Thats where it stands, EFI, TBI, or revert the carb to the Holley...
Performance over price any day, but not going to a shop for this one, anything over the stuff they have on their sites-real world applications I'd like to hear about how they went.
Thanks
 
Your terms are a little off. TBI IS EFI. It's just one form. There is TBI, Port or multi port, sequential and direct. It is all classified as EFI. The Edelbrock system you're referring to is sequential multi port EFI.
 
If you’re gonna do EFI might as well do port injection not throttle body. I have the small block Edelbrock ProFlo4 on my 340. Not perfect but runs pretty dang good. Now that I’ve had some time with it, it starts right up even after sitting in the cold for several weeks. Well cold for Virginia. Most expensive part is the fuel system if you do it right and put the pump in the tank.
 
So here is the manifold ( I think you are referencing) with Holley EFI.

006B27E3-709A-4EE7-940C-B38E898EE2BF.jpeg
 
If you’re gonna do EFI might as well do port injection not throttle body. .

Disagree depending on purpose and skill level and budget. There are LOTS of successful, good runnin cars running such things as the Holley Sniper or the FItech unit.

OP if you think you might want to start out a bit "easy" you can install such a thing as the Holley using the HP computer but with a TBI throttle body. You can even look around and find the throttle body used here and there. And if you decide to upgrade to individual port injection later, the same HP computer can still be used.

There is about a zillion ways to "skin this cat" as Crackedback says.
 
Disagree depending on purpose and skill level and budget. There are LOTS of successful, good runnin cars running such things as the Holley Sniper or the FItech unit.

OP if you think you might want to start out a bit "easy" you can install such a thing as the Holley using the HP computer but with a TBI throttle body. You can even look around and find the throttle body used here and there. And if you decide to upgrade to individual port injection later, the same HP computer can still be used.

There is about a zillion ways to "skin this cat" as Crackedback says.

ok, everyone has an opinion and I didn’t say they wouldn’t run ok, but if you’re gonna run a wet manifold you might as well just stick with a carb. Of course under a few circumstances I can see it the other way. Just my 2 cents
 
They all have their advantages and disadvantages. The larges being what your comfortable tuning. Modern fuel favors EFI in a big way. I have a friend who has install 8 Snipers for himself and friends that all live in our area. All are active drivers. He sent me a video of a warmed up 302 Ford running a Sniper he installed and it was idling a smooth as a Swiss sewing machine. He stated that was box stock. No driving or manual adjustments. If I wasn't $700 into a carb I'd switch especially now that Holley has a drop in fuel pump with built in regulator in the tank, which take s ton of hassle out of the fuel system
 
Cool-there is about $5000 worth of info right there, and the differences. Maybe more like $10K worth and I never knew there was so much to it either. But you guys helped alot.
It's for a 318, .030 over, Edlebrock RPM Performer heads and intake, has a Clay Smith cam H 274 B 450 450 lift...posting the spec sheet below. I'm pretty close to 2000 miles on the rebuild.
I can after reading this through pretty much figured multi-port injector on the 35900 Edlebrock, I have the heads, they supply the intake and all, with the Holley I would be sitting it right where I would be removing the Edlebrock carb (which will be for sale really cheap). Rusty , I never knew there was that much-and I have a feeling there is more than that. The one with a throttle body, I like it, but. Not much difference until the XT. That really changes the look of an intake. Still all in all works the same way as the other one, multi-port, but the area of vacuum, has a smaller area to create a higher vacuum. My 318's birth defect, vacuum, has been barely making it so far, before and after being rebuilt. I don't know how it was when it was stock. Thanks for all the info, it makes it pretty painless when everyone speaks up-Thanks!!!
Oh...now I wonder if lifter -roller or not makes a difference, going to see what that says....

Went out and looked at the wifes Sebring, and all that stuff went out the window for a second...I could put 6 stacks on her and re route the vacuum lines...:lol:...my ride would be for sale by the widow :eek::eek::eek: very next day.


(The price on that se
upload_2020-12-12_16-22-12.png
 
...well as it goes I went with Edlebrock EFI. It didn't happen fast like I wanted it to but Tech Support is quite the education. First problem was they're tablet was cracked corner to corner. I actually thought if the tablet wasn't on it wouldn't start-wrong. I wasn't ready for it to and it did.
The birth defect mine has is that trying to set the initial timing at 12°. It always wants to do 8°. I ended up using a kinda homemade piston stop for it, backing down and re-checking until I finally got it there (going back and checking it again pretty quick) but have this idea it's still off a degree or so...like just enough to make it run a little rough.
I had a hard time before I took the wet fouled plugs out also, took right off after that. It draws a lot of electricity. About a whole volt when it fires. I was going to replace the alternator/voltage regulator next summer, did it now just to make sure I wasn't missing out on any thing a new one could do for me, and now replacing wires as needed. Most of it is pretty much in great shape, there has been somebody under the dash before me, and I am fixing their stuff. Probably see a full wire harness replacement in a couple years. I solder when I crimp, its the only way they last on some of the bigger and heavier load wires. And the ignition system is totally isolated from the rest of the system, kinda neat for finding things that need fixed!
I don't think I would of liked the TBI type. Saw one right before I ordered this one. Didn't impress me any, plus it was on a mousestang 4 point something, I don't know much about those cars any way but it sure seemed like it was just regular non spectacular barely burnt them off and sputtered on down the road...was not impressed.
All in all it was an easy install, I got a little more smarts, affordable, and it seems like I am getting better mileage, it runs cooler, and weird thing, on the highway it gets to that 85 mark at about 1700 RPM. That used to be about 2600 RPM. Oh, 85, I don't think the speedo is right. I am replacing the cable and putting the clip that holds it tight to the back of the gauge on after I get one-friend says he has a few dozen to choose from. Pulled the cable up about 6 inches and it was feeling fat and fluffy in spot, probably causing speedo things to be wrong because it flexes funny if you twist on it-just needs replacing.
Thank you guys for the info, it did really make it easier. After 3 months of this and that I'd help someone install one and feel pretty confident about it, if your even ballpark with settings it still starts and learns while it is running!!!. Never like that with carburetors, always had a prayer going with those for some reason-even when they were running right.
Again, Thank you for the info, helped huge with the choice...

20210911_183512.jpg
 
The birth defect mine has is that trying to set the initial timing at 12°. It always wants to do 8°. I ended up using a kinda homemade piston stop for it, backing down and re-checking until I finally got it there (going back and checking it again pretty quick) but have this idea it's still off a degree or so...like just enough to make it run a little rough.


It draws a lot of electricity. About a whole volt when it fires. I was going to replace the alternator/voltage regulator next summer,

Be sure you don't have the timing causing what is known as "rotor phasing" issues, Google that. There are videos on how to check it

Also your voltage drop is very VERY likely due to the age--old issues with the bulkhead connector, ammeter circuit, and voltage drop in the ignition "run" circuit

Start by reading this:

Catalog

If you do not do this bypass or don't do it in this way, the article at least gives you an overview of the problem. As shown in the article, CHECK the bulkhead connectors for condition, and MEASURE voltage at points in the supply path to determine what is and where is the voltage drop

ALSO you can help the problem by installing a relay to operate underhood loads supplied by the key off the dark blue "run" circuit

Cut the dark blue "run" wire where it comes out of the bulkhead. Take the bulkhead end and us it to trigger a (such as Bosch) relay, and feed the relay through a large fuse or breaker off the starter relay "big stud." Feed the switched contact back to the engine bay end of the wire you cut, as well as the "trigger on" circuit of your efi.

By the way voltage drop in that circuit CAUSES OVERCHARGING because the VR receives low voltage and "thinks" it needs to charge more
 
The voltage you refer to the system needing is not the “EFI” system it’s the fuel system. See information in the post above. I’m running a stock alternator and have no voltage drop issues but have modified my charging system wiring bypassing the bulkhead as described elsewhere.

Also as referenced above there is another thread on here about the ProFlo4 EFI with detailed pictures of rotor phasing. Edelbrock has not corrected this issue as they claim it doesn’t exist. You will have the issue above 3K rpm.

And one last observation, I can’t tell what type of coil you’re using but make sure the coil you have is on the approved list of coils as it will fry the ECU if it doesn’t meet the specs.
 
...well as it goes I went with Edlebrock EFI. It didn't happen fast like I wanted it to but Tech Support is quite the education. First problem was they're tablet was cracked corner to corner. I actually thought if the tablet wasn't on it wouldn't start-wrong. I wasn't ready for it to and it did.
The birth defect mine has is that trying to set the initial timing at 12°. It always wants to do 8°. I ended up using a kinda homemade piston stop for it, backing down and re-checking until I finally got it there (going back and checking it again pretty quick) but have this idea it's still off a degree or so...like just enough to make it run a little rough.
I had a hard time before I took the wet fouled plugs out also, took right off after that. It draws a lot of electricity. About a whole volt when it fires. I was going to replace the alternator/voltage regulator next summer, did it now just to make sure I wasn't missing out on any thing a new one could do for me, and now replacing wires as needed. Most of it is pretty much in great shape, there has been somebody under the dash before me, and I am fixing their stuff. Probably see a full wire harness replacement in a couple years. I solder when I crimp, its the only way they last on some of the bigger and heavier load wires. And the ignition system is totally isolated from the rest of the system, kinda neat for finding things that need fixed!
I don't think I would of liked the TBI type. Saw one right before I ordered this one. Didn't impress me any, plus it was on a mousestang 4 point something, I don't know much about those cars any way but it sure seemed like it was just regular non spectacular barely burnt them off and sputtered on down the road...was not impressed.
All in all it was an easy install, I got a little more smarts, affordable, and it seems like I am getting better mileage, it runs cooler, and weird thing, on the highway it gets to that 85 mark at about 1700 RPM. That used to be about 2600 RPM. Oh, 85, I don't think the speedo is right. I am replacing the cable and putting the clip that holds it tight to the back of the gauge on after I get one-friend says he has a few dozen to choose from. Pulled the cable up about 6 inches and it was feeling fat and fluffy in spot, probably causing speedo things to be wrong because it flexes funny if you twist on it-just needs replacing.
Thank you guys for the info, it did really make it easier. After 3 months of this and that I'd help someone install one and feel pretty confident about it, if your even ballpark with settings it still starts and learns while it is running!!!. Never like that with carburetors, always had a prayer going with those for some reason-even when they were running right.
Again, Thank you for the info, helped huge with the choice...

View attachment 1715843643
Get rid of that fire hazard of an air cleaner.
Your welcome.
 
One advantage of TBI it maintains an old school look. With a standard air cleaner, looks like a carb.

3400EE76-2E54-4F76-B926-0E2651B77C9D.jpeg
 
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