Changing 95 Mustang SEFI to 93

[Johnnyb]

Years ago I did a conversion with a 1995 Mustang SEFI motor. At the time I understood about the incompatibilities but thought that I could overcome by using the motorsport wiring harness and the correct computer/sensors/distributor from a 1993.

Long story short, it never work quite right. They're always seem to be a power delivery problem around 3,000 RPMs where the motor would just cut out.

Now I have purchased a 93 Cobra set up from another member here on classicroncos.com. I was just wondering if anybody had any pointers or suggestions as to what challenges I might face as I take the top end off the 95 motor and replace it with the top end from a 93?

Thanks in advance!
JohnnyB

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[DirtDonk]

Interested in hearing answers too. Yours should have worked. Nothing that I can think of would stop you from using your existing hardware, plus a few changed sensors and the correct computer and it should have run just like any Ford Mass-Air engine.

Did you change your MAP sensor to a BAP sensor at the same time? Did you check the distributor for any faults? Fuel pressure? Computer issues?

Anyway, good luck with the new setup.

Paul

 

[BanditBronco]

All your hard parts should be the same other than the ignition side. So technically you don't have to pull the intakes or anything. Just distributor and harness. The injector plugs could be different, also , the maf isn't compatible without a tune, and lastly, I believe the pin out numbers are different. So say you wanted to use your old harness and just retrofit for non tfi style ignition, you couldn't plug the 93 computer into the 95 harness. I will need a fact check on that but I am pretty sure they have different ECM plugs due to wire amount.

 

[Johnnyb]

Thanks BanditBronco!
I'm going to use all of the sensors, computer, MAF, and distributor from a 93. I have the Ford Motorsport fuel injection harness.
After I'm absolutely certain that only the lower end is 95, then we'll see how we're doing.
Great advice and thanks for the post.
-J


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[Johnnyb]

Thanks DirtDonk,
The project's been dormant for quite some time so I'm going to start from the block and work outwards with all new parts from a 93. Computer, harness, distributor, MAF, everything.
Fortunately I already have the shorty headers O2 sensors installed, but I'll probably replace the sensors as well.
If SEFI doesn't work after that I'm going to rip it off and replace it with a Holley sniper!

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[BanditBronco]

Your 95 upper intake has a 45* kick to it where the throttle body mounts, the 93 upper is 90* throttle body mounting. You might have to reconfigure throttle cable mounting for it to work correctly.

 

[jamesroney]

If it is really a 93 cobra set up, then it should work fine.

Many systems are sold as 93 cobra, but are really just later 5.0 GT40 lowers with the 93 cobra upper. It can be made to work, but you have to make sure that your lower is configured for EGR, and has the IAT (or ACT) sensor provision.

The 93 cobra upper has an integral EGR "spacer" and a ton of vacuum ports that you don't need. I plugged mine with threaded plugs. The only vacuum that you need is PCV, Brake booster, and FPR.

I like to run the 96 Explorer fuel rails, because they dump in the rear, and they have the fuel pressure port on top. I don't run EGR, so I don't need the coolant in the intake. This makes the coolant stagnate in the heater circuit...but it seems to be accurate enough. When you don't run EGR, and the motorsport harness...it will throw a code. The Ron Francis / RJM harness solves that.

 

[Johnnyb]

Thanks for the great advice! Here is what I bought: https://classicbroncos.com/forums/attachment.php?attachmentid=510775&d=1602541215
It looks like the right stuff!

If it is really a 93 cobra set up, then it should work fine.

Many systems are sold as 93 cobra, but are really just later 5.0 GT40 lowers with the 93 cobra upper. It can be made to work, but you have to make sure that your lower is configured for EGR, and has the IAT (or ACT) sensor provision.

The 93 cobra upper has an integral EGR "spacer" and a ton of vacuum ports that you don't need. I plugged mine with threaded plugs. The only vacuum that you need is PCV, Brake booster, and FPR.

I like to run the 96 Explorer fuel rails, because they dump in the rear, and they have the fuel pressure port on top. I don't run EGR, so I don't need the coolant in the intake. This makes the coolant stagnate in the heater circuit...but it seems to be accurate enough. When you don't run EGR, and the motorsport harness...it will throw a code. The Ron Francis / RJM harness solves that.

 

[jamesroney]

Thanks for the great advice! Here is what I bought: https://classicbroncos.com/forums/attachment.php?attachmentid=510775&d=1602541215
It looks like the right stuff!

Yeah, I was afraid of that. You did not buy a 93 Cobra set up. You bought a 98+ Explorer lower and a 93 Cobra upper. The giveaway is that there is no EGR hole. (which you don't need...) and there is no place to put the Intake Air Temperature sensor. (which you do.)

Start looking for a 93-97 GT40 lower.

Send me a PM, and I can help you out.

 

[Johnnyb]

So will the 95 Cobra lower that is already on the motor bolt to the 93 upper that I just bought?
I'd send you a picture of what I'm running now but I couldn't get the hood up. Apparently in dormancy, the hood release broke.

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[jamesroney]

If your lower is an original 1993 Cobra lower, it will have an engineering number of F3ZE-9K461-BD. Overpriced, Very rare, very hard to find, and usually broken.

The 94-95 SN-95 intake will have F4ZE-9K461-BC. Those are good.
The Motorsport version is the M-9K461-A50. Works the same but has the giant "made in China" on the bottom.
The 96-early 97 Explorer intake is F87E-9K461-BA. That's just as good.

The 97.5+ Explorer intake is F87E-9K461-BB. That's the one with thin walls, and no EGR, and no IAT. Lots of these out there.

I'm not sure about the marine version of the GT40. I'll have to do some research.

The original Cobra upper did not have a provision near the throttle body for the "Ford Racing" sticker. It just had a rib. The vast majority of Cobra uppers were sold over the counter from Ford Motorsport, and have all black logos. The originals had the red and black. (and no, it doesn't matter...)

 

[jamesroney]

Here's some pics of the uppers. You can see the Ford Racing one is cast different. But they all work the same.

 

[Johnnyb]

Yeah, I was afraid of that. You did not buy a 93 Cobra set up. You bought a 98+ Explorer lower and a 93 Cobra upper. The giveaway is that there is no EGR hole. (which you don't need...) and there is no place to put the Intake Air Temperature sensor. (which you do.)

Start looking for a 93-97 GT40 lower.

Send me a PM, and I can help you out.

THX! PM Sent!

 

[Johnnyb]

Does anyone have the part number for the ECM/Computer I will need with the setup suggested by jamesromney above (with a manual transmission)?

THX,
-JB

 

[Johnnyb]

Is this the right computer for 87 to 93 Mustang EFI?

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