Coyote swap questions

89GreyFox

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Apr 12, 2020
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Hey guys so I finally purchased me a junkyard 5.0, already purchased a set of gt cams and I take. My question is and I already know it would easier to buy the control pack but im refuse to spend 1500 lol can I buy a used computer and gas pedal and then buy a new factory harness that’s complete? Then just have everything tuned from that point? Years ago I swapped a ls in a 95 stang and took my time and set it up this way, used a different engine, computer, pedal and harness. New to ford mod engines and didn’t know if I could do this with the swap.
 
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89GreyFox

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I’m sure you could, but a ms3 gold box with harness is $1200 right now. If the $1200 is gonna make or break you, the rest of the swap is going to be quite trying.
That’s my question, I don’t need to spend anything if I can wire everything the way I mentioned. It worked with my ls swap but this is a different beast.
 

Hoytster

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At a bare minimum, you need to disable PATS as well as all the other body module inputs that the stock ECU expects to be connected. You also have to figure out how to convert to a returnless fuel system. Once you start putting together the cost of the additional parts, tuning costs, and time put into getting everything figured out, your better buying the control pack or another ECU. It's honestly a drop in the bucket once you start adding up the rest of the parts (if your trying to do it right).
 
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96pushrod

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At a bare minimum, you need to disable PATS as well as all the other body module inputs that the stock ECU expects to be connected. You also have to figure out how to convert to a returnless fuel system. Once you start putting together the cost of the additional parts, tuning costs, and time put into getting everything figured out, your better buying the control pack or another ECU. It's honestly a drop in the bucket once you start adding up the rest of the parts (if your trying to do it right).
By the time someone is into the cost of a used ecu, harness, pedal, and getting it flashed they’re well onto the way of a stand-alone system - with lots more possibilities.
 

2000xp8

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If somehow you were to get the stock ecu and harness to work, it would still need to be tuned before you ever started it.

Save yourself the time, headaches and I bet in the long run, money, and buy the control pack. Swaps are money pits...
 
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89GreyFox

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By the time someone is into the cost of a used ecu, harness, pedal, and getting it flashed they’re well onto the way of a stand-alone system - with lots more possibilities.
I already have all that, local shop is gonna do the flash and dyno for 300 bucks. 300 vs 1500 is kinda a big deal if you cns make things work. That’s the plan anyways.
 

89GreyFox

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Apr 12, 2020
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At a bare minimum, you need to disable PATS as well as all the other body module inputs that the stock ECU expects to be connected. You also have to figure out how to convert to a returnless fuel system. Once you start putting together the cost of the additional parts, tuning costs, and time put into getting everything figured out, your better buying the control pack or another ECU. It's honestly a drop in the bucket once you start adding up the rest of the parts (if your trying to do it right).
I have cost figured up to around 5600. I already have the trans as well. Doing all work myself and following foxcast media from YouTube his build.
 

ThinBlue502

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I believe the internal anti theft stuff in the ECU would prevent it from being used in a different car. But not sure.
I believe this is the hang up, can’t remember for sure. Regardless, you pretty much have to buy the Ford control pack.
When I crunched the numbers on the coyote swap vs. say, a 427 stroker swap, it was ridiculously biased to the Windsor swap. At least right now. Maybe in another 5 years you’ll be able to pull junkyard coyotes at stupid cheap prices (IE: Chevy LS engines), but for now it’s just not as cost effective when you add in all the extra stuff. For me, I don’t want to drive a car without power brakes, power steering, A/C, etc. that most “bare bones” coyote swaps come to. Good luck with your swap, the coyote is an amazing machine.
 

Hoytster

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I have cost figured up to around 5600. I already have the trans as well. Doing all work myself and following foxcast media from YouTube his build.

Do you have the full return-less fuel system from a the car you pulled the engine from? You'll need the stock fuel rail pressure sensor, fuel pump driver module and fuel pump for the stock ECU to attempt to make it work. The return-less fuel system is usually a big hang up for people because then you have to either modify the exiting tank/lines, or put in a fuel cell and modify that and the lines (more $).

Also, has this shop done this before successfully? I would question them and make sure they have actually done this full conversion before and know all the in's and out's to getting the stock ECU to work. The fact they quoted you $300 to do the tune makes me question that. I know people have successfully got the stock ecu to work on an s197 3-valve, but they were able to re-pin the stock 3-valve harness and use the existing body modules (and existing returnless fuel system) to get it all to work. A fox is a lot more work since it has none of that. You just want to make sure you don't waste $300 and have a brick sitting in your driveway after having everything swapped over.

You can definitely do the swap on the "cheaper" side if you do all the work yourself, but don't be surprised if your costs start to snowball at the end.
 
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Hoytster

I don't dare do that to my Knob
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And BTW, not trying to discourage you, I would love to see you work this all out and get it to work. Just want to make sure you understand all the hurdles you will have to overcome. That's the reason most people go stand alone or control pack.


EDIT: One more thing concerning Foxcastmedia, if you watch most of their videos the guy does try to make sure you understand that cost for the swap is going to be variable. I think he quotes around $5400 to do the bare bones swap in a 96-04 mustang GT manual mustang, which is about as cheap as you can get considering those cars already came with a "modular" based motor. The prior years require more parts and therefore more money and even he says expect between 10-20K to do it right. Just some perspective.
 
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Hoytster

I don't dare do that to my Knob
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I already have all that, local shop is gonna do the flash and dyno for 300 bucks. 300 vs 1500 is kinda a big deal if you cns make things work. That’s the plan anyways.

Also, thought your original question involved having to buy a stock ECU, complete harness, and gas pedal?

What trans that you already have do you plan on using?
Do you also have the MAF and relay box needed to power everything also?
 
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96pushrod

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I already have all that, local shop is gonna do the flash and dyno for 300 bucks. 300 vs 1500 is kinda a big deal if you cns make things work. That’s the plan anyways.
Your first post states you planned on buying all that stuff. Not that you already had it.
 

89GreyFox

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Do you have the full return-less fuel system from a the car you pulled the engine from? You'll need the stock fuel rail pressure sensor, fuel pump driver module and fuel pump for the stock ECU to attempt to make it work. The return-less fuel system is usually a big hang up for people because then you have to either modify the exiting tank/lines, or put in a fuel cell and modify that and the lines (more $).

Also, has this shop done this before successfully? I would question them and make sure they have actually done this full conversion before and know all the in's and out's to getting the stock ECU to work. The fact they quoted you $300 to do the tune makes me question that. I know people have successfully got the stock ecu to work on an s197 3-valve, but they were able to re-pin the stock 3-valve harness and use the existing body modules (and existing returnless fuel system) to get it all to work. A fox is a lot more work since it has none of that. You just want to make sure you don't waste $300 and have a brick sitting in your driveway after having everything swapped over.

You can definitely do the swap on the "cheaper" side if you do all the work yourself, but don't be surprised if your costs start to snowball at the end.
Yea he’s legit, also a friend, this is with me doing all the work then he’s just gonna tune it for me. I have a doner sn 95 car that I’m gonna use the fuel system for, also a fuel cell from my drag car that I built.
 

Hoytster

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Yea he’s legit, also a friend, this is with me doing all the work then he’s just gonna tune it for me. I have a doner sn 95 car that I’m gonna use the fuel system for, also a fuel cell from my drag car that I built.

SN95 is a return style fuel system. Do you mean out of a new edge? Has to be returnless.

Assuming he tunes using HP tuners? The PATS delete is really the easy part of all this anymore. A couple years ago this was never even an option.
 
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2000xp8

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I think the biggest concern here should be what if you buy all the stock stuff, spends days or weeks trying to make it run, then fail.
Not only will you be out all the money, but all the time and likely at this point frustration could derail the entire project.

When I did my swap, there wasn't much out there for swapping between mod motors and foxbody's.
While it did only take about 7 wires to make it run, that was months of reading diagrams from 2 cars and having 2 guys that work on mustangs for a living giving me advice and shop time (along with no cost tuning and dyno time). And that was an engine less complex and less computer controlled.
When I was done I had a harness that was lightened by about 75%.
In 2020 I likely would not do it the same way.

Running the fuel system return style was a no brainer to me.
I wouldn't be surprised if you could just use stock fox fuel lines with AN adapters with a 155lph pump and aeromotive regulator.

I truly wouldn't be surprised if in the end, the control pack turned out to be the cheaper solution.

eight5fox's total of 7k, sounds like a financial victory to me...
 
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