To inject, or not to inject.. that is the question...

TF Mondo

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Apr 18, 2005
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Have you switched over to fuel injection and now regret it? Like a lot of people, I'm hot on all the new fuel injection options, especially the retrotek powerjection and the Edelbrock system. But.... I was talking to a couple of local mechanics recently that specialize in fuel systems (one used to be a tech for Holley) and they told me it would be "the biggest mistake you could make". They said that if I think screwing with a carb is a pain in the butt, just wait until I had to screw with all the things that could run amok with EFI. Anyone have any thoughts? I like the fact that by not buying one of these systems I'll get to keep $2k to $3k sitting in my wallet, but I'm still on the fence.
 
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The real question about whether or not you should convert to fuel injection is how much do you drive the car? I converted over several years ago, and absolutely love it. I was using the car as daily transportation at the time and putting over 15,000 miles a year on it. I picked up considerable mileage improvements (22 mpg compared to 17-18 with a carb), and was quite happy with the way it performed.

I did all the work myself using stock H.O. components and saved big $$$. I didn't keep records for all the small pieces I needed (there were LOTS) but the total bill for me was around $750 to fuel inject. The biggest problem for me was that the stock stuff ran out of air a bit too soon for my liking, but I do plan on swapping over to GT40/Cobra intake stuff. I already have the larger mass air and 24 lb/hr injectors.

If you are only going to drive the car on weekends or once or twice a month, don't go through all the hassle. There is a ton of changes to make to swap over......make sure that you are getting your time and money's worth before you commit to making a change this major to your car.

All that being said, I love my efi have never had a problem with the system that was any harder to fix than working on a carbed system. The largest problem I ever had with it was following peoples advice that you could use an in-line pump to feed the system. I learned what vapor-lock was all about. Switched to an in-tank pump and never had another problem.

It's your car, and your money (lots of it). Which ever way you go, don't second guess yourself, just enjoy driving the car.
 
Ditto on what 66fastback said, but I'll add that for a daily driver, using a small carb in connection with an EFI style cam grind can give the same results as EFI, with the exception of big altitude changes (as in going up or down 2000-3000 ft or more) The roller 5.0 I have in my 89 Ranger runs and drives exactly like it's got EFI, day in-day out (no altitude changes here in S. Louisiana) Daytime temps range from 25*F in January to 95*F in July. Carb is a Holley 570 SA, cam is a factory F4TE hyd roller with 1.7 rockers. Intake is an "old school" Ford Racing A321. Cold starts at 25*F ? No problem, even with the choke assembly removed (completely)
 
most people that have problems with EFI either dont have the right tools, or had problems with the early systems and labeled EFI a problem and gave up. the reality is that the very early systems did have problems, like the EEClll, but as the systems were refined, their reliability has improved greatly. as for after market systems, they dont have to follow the same rules the OEM guys do, so they have more freedom to develop systems that are geared more to performance than the OEM systems.

that said, i agree with the others that you should determine first what your plans for the car are, and work accordingly.
 
I dont really see a reason NOT to. Almost every car since the late 70's has been fuel injected and they are all fuel injected. If it were a bad technology, it would have faded away.

What kind of motor are you running? If you are running a 302, go with a mass air setup from the 87-93 mustangs. Cheap, easy and can find parts everywhere.
 
in response to xoxbxfx "I don't see any reason not to..."

I am not going to argue that there is any thing wrong with converting to efi, it's one of my favorite things about my car. I adopted an attitude many years ago that it is my car and I will modify as I see fit. I have scavenged parts from cars from nearly every decade of production in order to upgrade the reliability and efficiency of my ride. Carbs are ancient technology. I am a firm believer that if Fred Flintstone didn't have feet, he would have had a carb.

It is a matter of practicality for most people. There is a lot of time and money invested to convert the car over when it is already set up for a carb. It would be SOOOOOO easy to buy an Edelbrock Performer intake and carb, or a small Holley, and bolt it on there. Done. There's a lot to be said for doing that.

I never do things that way, but there's a lot to be said for staying with the old technology.....like the single reservoir master cylinders on the 65-66 cars. :D Remember, sometimes Fred had Barney to help push (and stop).......
 
My last car I built was injected, the one I have now as my fool around car is carbed-

Injection is good- better MPG, drives like a new car- I would only do it if I you are going to use a Ford OEM HO system though-

I went with a carb on this one because I just wanted the more old school look-

If I drove the car everyday- it would be EFI hands down
 
EFI saves much engine wear. Most cylinder wear happens when you first start the car and the choke is on. Excess fuel washes down the protective oil film in the cylinders. EFI engines often still have fresh cylinder bores after 100,000 miles. That's a real plus if you drive it a lot.
 
"I am a firm believer that if Fred Flintstone didn't have feet, he would have had a carb. " That's beautiful....

It's a 66 convertible, slightly warmed, bored over, etc. I put an edelbrock performer manifold and a Holley 650 carb on there about 5 years ago and have never been happy with how its performed. The car has never been a daily driver per se, as I've always done most of my commuting on my motorcycle. But it did get driven quite a bit when I was a single guy living in the city. It just strikes me that it would be way more enjoyable to drive with EFI, especially in light of all the carb issues I've had over the years. I don't have the time these days to put in anything other than one of the new bolt on systems (retrotek or edelbrock), so thats what I'd be leaning towards.
 
Mondo says "That's beautiful...." sniff, sniff. That's the nicest thing anybody has ever said to me......

You might include a bit more info about the car. You say slightly warmed.....any cam? Heads? Rear gears? If you haven't done rear gears, stop worrying about the induction and slap some gears in there.....then worry about the intake. Gears make you love your rear end.....wait that doesn't sound right......

anyway you will wonder why changing gears wasn't the very first thing you did to the car.
 
For me, its no choice, EFI all the way, people get confused by EFI and think it makes things more complex...which isnt true, the engine still works exactly the same way, you just need to have a good understanding of EFI if you havent worked with it before...in my opinion the OEMs make EFI way too complicated to begin with, everyone seems to love MAF systems...and they are good, for minor mods, but for something major I prefer a speed density system anyday(at least a programmable one) I use a standalone in my neon and love the hundreds of adjustment points for both fuel and spark(not to mention the ability to run the car off of Ethanol, Methanol, Propane, Hydrogen, or anything else that can explode in a combustion chamber) I realize that most people arent going to want to mess with a standalone, but even OEM EFI is better than a carb and a points distributor, my standalone though cost me a total of $700 by the time you add in fuel pump, 1:1 fuel pressure regulator, the ECU itself, and a wiring to make a harness out of(this of course didnt include a manifold or injectors since the neon came with those)
 
EFI saves much engine wear. Most cylinder wear happens when you first start the car and the choke is on. Excess fuel washes down the protective oil film in the cylinders. EFI engines often still have fresh cylinder bores after 100,000 miles. That's a real plus if you drive it a lot.

The cylinder wear or lack thereof with the newer motors isn't due to the missing carb. It's due to the factory using tighter tolerances & low tension rings in building them. Hypereutectic pistons and low tension rings are THE reason the late 80's on up motors seem to have lasted longer than the 50-60 & 70's motors did.
 
"I am a firm believer that if Fred Flintstone didn't have feet, he would have had a carb. " That's beautiful....

It's a 66 convertible, slightly warmed, bored over, etc. I put an edelbrock performer manifold and a Holley 650 carb on there about 5 years ago and have never been happy with how its performed..

Let me guess..........that 650 Holley was a double pumper and you were still running a points ignition. :nono: If that's what you were running it's no wonder it ran like crap most of the time. What were the rest of the engine specs?
 
It's expensive to convert to EFI, but it's really worth it IMO. I did an EFI conversion and the car ran better, had more power and much better throttle response. Plus I have a lot of short trips, so no warm up is a great advantage of EFI.

I also believe that EFI motors last much longer than carbed motors due to better fuel distribution, vaporization and metering. They also get better gas mileage.

I think that troubleshooting with a computer is easier than without one. I put my last EFI system together with a number of used sensors and parts. I had a few issues, but it wasn't hard to diagnose and solve them. One thing I would NOT recommend anyone do is to pinch pennies on the harness - IMO electrical gremlins are one of the crummiest things to ever try to figure out. There are a lot of wires in an EFI system, so to me it's well worth it to buy a harness that's new or at least very good condition.

I'm using an X3Z EECIV '93 Cobra computer and I'm very happy with how it works.
 
The largest problem I ever had with it was following peoples advice that you could use an in-line pump to feed the system. I learned what vapor-lock was all about. Switched to an in-tank pump and never had another problem.

Hi,

Can you explain this a little more? I have a holley in-line on my EFI project, just haven't gotten the body panels back together to for a test drive. How does the inline fuel pump create vapor lock?
 
Hi,

Can you explain this a little more? I have a holley in-line on my EFI project, just haven't gotten the body panels back together to for a test drive. How does the inline fuel pump create vapor lock?

The problem is air in the lines. With a carb, the air is "burped" out, but not so with EFI.

The fix has nothing to do with inline vs intake pump and everything to do with the tank having a "sump" or baffles so that the pump doesn't suck air during hard acceleration or cornering when the tank is close to empty.

Most tanks designed for an in-tank pump are also sumped, so in a way switching to an in-tank setup does fix the problem.

I went with an in-line pump using the stock tank and havn't had a problem, although I rarely let the tank get below 1/8th.
 
"How does the inline fuel pump create vapor lock?"

I don't think that the pump itself causes the problem.....I just think it adds to it. Those pumps can get very hot......especially mounted in-line. When you mount the pump in the tank the gas cools the pump. This not only makes the pump last longer, but it also keeps the overall temp of the fuel in the lines cooler as well. I'm pretty sure that the main reason the manufacturers mount the pumps in the tank is the cooling effect on the pump.

We have had a couple of Mustangs that we (my dad and I) converted to fuel injection.....my 66 and his 67. Both cars developed big problems with vapor lock using in-line pumps. The problem wasn't "sucking air" when low on gas or fuel sloshing. It would occur during steady cruise on the highway, or just normal city driving as well. The problem was heat boiling the fuel in the lines. We live in Texas, and during the summer we would both experience a condition where the cars would basically shut down. You would have to wait for the fuel in the lines to cool down enough to be able to drive the car again. We never tried to insulate the fuel lines, that might have helped.

We had the pump and fuel lines routed well away from the exhaust systems, and the pumps mounted below the bottom of the tank level. We tried a number of different pump manufacturers and eventually just pulled the stock tanks and had fittings brazed into the tops to mount the in-tank pumps. Problem solved in both cases.

as ForceFed70 stated, fuel tanks designed for use in efi systems have baffling or sumps. We did not use any of these, and have not had problems, but we aren't racing the cars and keep the tanks well above 1/4 tank. If you have intentions of racing the car, then look for a tank that keeps the fuel around the pickup, or add a surge tank to the system.
 
By "warmed up a little" I mean .. a ... little. Other than the Holley and the new manifold, its been bored over 30 and I put the high output exhaust manifolds on there and went to dual exhausts. Ignition is a Pertronix. If I still had points in there I think I would have torched the car long ago.

66Fastback - I never even considered changing my rear gears... its a convertible so I never really wanted to make it lightning fast for fear it would twist in two, but what do you suggest?