I know virtually nothing about the Chrysler EFI systems, probably because they decided to sit the '80s and '90s out as Ford and Chevy duked it out on the street.  So I'd approach it like adding EFI to anything where EFI wasn't available from the factory.  A complete kit is the way to go in that scenario.  I can't recall hearing anything bad about the Sniper, and plenty of good, so I'd say go for it. 

Thanks guys!

It depends on what you are used to working on, and the system you are working on.  Good EFI does a lot of self diagnostics.  Then generally you just need a multimeter and the know how to use it.  Initially a lot of carb guys were resistant to EFI, but ultimately  think they didn't really know how to tune carbs all that well either. 

Toploader wrote:

TKOPerformance wrote:

It depends on what you are used to working on, and the system you are working on.  Good EFI does a lot of self diagnostics.  Then generally you just need a multimeter and the know how to use it.  Initially a lot of carb guys were resistant to EFI, but ultimately  think they didn't really know how to tune carbs all that well either. 

I have only ever had classic cars with carbs, so installing an EFI system and setting it up seems a bit daunting. I am sure I could work it out and it is just a matter of learning something new. I do wonder how much is involved in converting from a 4 barrel carburetor to an EFI. Is this a day's work, or is it much more involved than that. Also, what might be the rough total cost to install EFI?
 

It depends on the system you use.  There are self contained EFI systems now that bolt in place of a carb and require minimal wiring and no tuning.  You will have to make some changes to the fuel system as carbs and EFI operate at radically different fuel pressures.  Typically you will have to add a return line back to the tank with EFI, unless the system uses deadhead style fuel delivery, but these systems are hard on the fuel pump, and though OEMs flirted with them, all have since abandoned the idea due to concerns about reliability.  You can buy an EFI ready tank, sending unit, etc that will bolt in due to the popularity of the Mustang. The guys who go this route want EFI with the minimum of fuss, don't mind if they leave a couple HP on the table, don't have time to mess with it, and cost is less of an issue than ease of installation. 

On the other end of the spectrum you can convert to the EECIV system used on the Fox Mustangs using either Speed Density or Mass Air and gain the ability to tune the system via software and a laptop.  Swapping the mechanical parts of the EFI is relatively simple, and you will have the same fuel system concerns, though the wiring is considerably more involved.  Then there's the tuning aspect.  The factory system is actually quite good and will run almost any engine you put it on (excluding forced induction applications, unless you modify it accordingly), but to optimize it you need to tune it or have it tuned. The guys that go this route typically want the most out of their engines, don't mind learning a new skill (if they don't already know it), and have plenty of time to mess with it.  There can also be a considerable cost savings going this route if you for example buy a used engine that already has all the EFI hardware on it. 

Chaplin wrote:

If I switch to EFI, I think I will go with one of these set ups. Mounts in the factory location, reuses the factory supply line and does not need a return line. Looks like it makes the switch to EFI as simple as possible.

https://m.youtube.com/watch?v=10xrBib8p6g

No offense but, if "simple as possible" is what you are looking for I recommend you simply leave a pot on it.  Maybe go to a Edelbrock or just leave an Autolite 2100....simple, works fine and lasts a long time.

BB1

Last edited by Bullet Bob (11/20/2020 8:14 AM)

Chaplin wrote:

How about simple and effective?

What potential issues do you see with that set up?

Are you asking what issues do I see with aftermarket injection?  Well, I run the Ford system, which was no problem at all until I started messing with it.  Then I had to negotiate the "learning curve".  But if you a going to run relatively stock the EEC-IV system with Mass Air and the A9L, M, or P computer is pretty hard to beat...and relatively cheap.  The biggest issue will be wiring but factory harnesses can be cut, chopped, re-routed, and made to be very reliable, regardless of what some will tell you.  Or, with not too much effort you can buy some good wire and make up your own P&P harness to run the engine in an otherwise stock car.  The fuel system will need to be dealt with regardless but that doesn't need to be high buck rocket science either...just a bit of time and an external Walbro pump...I've been running one all over the country for over ten years and 35K miles.
I just don't see any reason to spend $2500+ on something that can be put together for less than half of that and will run as well or better.

JMO

BB1
 

No, I was just wondering about potential issues with that Holley fuel pump set up. It seems like a very simple way to plumb your system to convert from carb to EFI, regardless of which EFI system you use.

I can see myself staying with a carburetor for a long time to come. Surprisingly, this discussion has made me realize that a well tuned carburetor is the simplest.

Here's the real question: how do you use your Mustang?  If you stay local and only take short trips then maybe its worth the gamble.  If you take the longer trips a lot of us have gotten into with our cars then I say its in no way worth it because you aren't going to drain the gas tank and swap a fuel pump (that you likely won't find locally anyway) on the side of the road.  That story ends in an unplanned overnight or several day stay, a tow bill, a garage bill, etc.  To me its just not worth it.

I'll also add that the OE type system is not any more complex than any fuel system on any car truly built for power.  Every fuel system I've ever built for a vehicle designed to make real power (north of 400) has used a bypass regulator with a return line whether it had a carb or EFI.  Once you start making serious demands on the fuel system a return regulated system has a lot of benefits, even for a carb.  One of the big ones is that it keeps the fuel cool.  It likewise takes the load off the fuel pump, and whether its electric or mechanical that's always a good thing for longevity.  Then there's keeping consistent pressure at the carb's needle and seat, which ensures no issues with the float(s), no fuel spewing out the vents, etc.  A regular OEM system is fine for a stock or lightly modified engine, but when you start looking to double OEM output these are things that start to become important.

Chaplin wrote:

But once it's done, its duty will likely be limited to trips within a 3 or 4 hour range of the house.

Although if I did take a trip across country, I would travel with a number of replacement parts like a fuel pump (regardless of which type of fuel  system I used), ignition module for the distributor, coil, fan belt, etc., so that any breakdowns could be fixed on the side of the road and not leave me stranded for days waiting for replacement parts to arrive.

I read this with some curiosity... It sounds like you are scared to drive the car? I feel that if you rebuild the car, replace the worn out and suspect components, then it should be about as reliable as a late model vehicle. Cars are cars and they all run the risk of something going wrong, no matter what the year is or make of the vehicle. About the only thing I would ever carry with me is a back up Pertronix module. Other than that, I wouldn't give it a second thought and you always have plenty of parts stores if something ever did go wrong. That is what I think anyway...
This discussion on EFI has really swayed my thinking to stay with a carburetor. I drive my car frequently, but it is not an everyday driver. For the use it gets, I think I can live with a carburetor and keep things simple.

Last edited by Toploader (11/21/2020 5:33 PM)

Someone on here a few years ago said that his "emergency kit" consisted of an empty credit car, a charged cell phone, and a AAA card.  Makes good sense and I nearly embrace that line of thinking...still have to pack a few incidentals on the Bash trips.

As for driving it...well, somewhere on here is a pic of our Heap and Glens 65 5.0 at the top of Pikes peak back in 2011.  Both were equipped with EFI and neither behaved any differently at 14115 than at the lower elevations.  I'm pretty sure your dribble pot wouldn't be as friendly.
The other thing I recall about that trip was the guy with the temperature gun at the bottom.  They wouldn't let you leave the park if the brakes were too hot.  I just rode down with the AOD in 1st gear and he checked my front brakes three times...couldn't believe that old car could have brakes that cool.
That was also the trip (To the Kalispell Bash) were Glen was gonna pull in for gas "at the next spot, I promise".  We finally stopped in Rawlins and my twenty gallon tank took 18.5.  I guess I had the fuel pickup adjusted just about right.  Modern mesh pick-up screen, stock tank, no baffles, external fuel pump.

BB1
 

TKOPerformance wrote:

But I can tell you that I long ago learned not to do something I knew was marginal or not t best way to handle something.  That stuff bites you in the @$$ every time. 

Got that right! Some things I am just happy to pay the money and get it done right, by someone that knows how to do it.