My codriver blew up our 1995 v6 mustang. With the 3.8, after months of searching we finally found a new one from a 2000 new edge. Although it's the same, there are some differences. All the mustang groups are actually very unhelpful and just make fun of me for putting effort into a v6 mustang. But so our newer 3.8 has the different intake design and in theory should make 40 more horsepower. Our plan will be try to use at much of the 1995 wiring and stuff and transplant it onto the 2000 engine. Then bolt it all up to our amazing T5 transmission. I think that will work, but hell if I know.
You'll want to verify the following for yourself; engine management went from EEC-IV to EEC-V in 1996, so there's a change of ECU controlling the engine between your 1995 car and 2000 V6 engine. I'm positive there are wiring changes to go with that change as well as the change to OBD-2 from OBD-1. There's going to be sensor and actuator changes at the engine to support the changes that took place to make more power; I believe that was some kind of dual-stage intake manifold configuration, from memory. Anyway, you've got controls and wiring changes to bring the car up basically to deal with the 2000.
I'm wondering if it would be easier to just use the 2000 engine as a short block donor to get your '95 running again. It seems a lot easier from here.
In reply to pres589 (djronnebaum) :
we thought about just using the bottom end. but for whatever reason we don't want to disassemble it
It in theory should be comparable to a V6 to V8 Swap. If you don't change any of the main harness, (meanng you plan to keep your stock wiring and computer) you shouldn't need to worry about the change in engine management. You are going backwards, technically speaking. EEC-IV is LESS of a pain because it was less controlling of everything. To my knowledge there isnt any significant changes to the engine itself. I would just be very sure there are no additional sensors due to the new engine management system and if there are make sure you connect the existing lead to the correct sensor. You may need to extend some wires if the sensor location moved. As for the intake change.. again, its very common in V8's. The 5.0's especially, but even placing a PI intake on a non PI long block. There isnt any significant concern there either. Your first start may be a bit rough until the computer learns, but you sholuldnt have any major problems with the swap.
Worse case, DON'T strip to the short block. Swap your original intake on to the long block (no teardown required) to get it running.. then swap the new intake on.. or dont.. but you will be back to a running car
In reply to peanutpckrupper :
I've been trying to join that forum since friday and it won't let me register. it's annoying.
You will not be able to use any 1995 wiring, there is a lot of "you can't get there from here" because the two engines are controlled differently. I am pretty sure that they are different under the dash, too.
In reply to Pete. (l33t FS) :
what do you mean not use any?
Really need to get a copy of both wiring diagrams for both cars and make a comparison. It won't have length data or connector types shown but it should still provide basis for the differences.
The ECU is going to be different, on one end, and on the other there's controls on the engine that are different. So the stuff in the middle has to be different for this to work. A complete donor car seems like the easiest way forward OR doing a custom re-wire to support the new engine & ECU in the old chassis.
My 2 cents, I do this kind of thing on aircraft, not cars.
I think I would reconsider the reluctance to strip it down. If the biggest difference in power is just the intake, I'd do what DJ suggested and just swap all of your ancillary bits to the new engine.
fastest and arguably the most reliable way to get it running (who wants to lose a race weekend chasing down wiring issues from all of the work to swap it as-is?) and then see if there is a way to migrate the new intake over. At that point it would be the same as upgrading your intake and I'd imagine there is info on if and how to do it.
In reply to jfryjfry :
It's the cylinder heads along with the intake. 99-04 v6 mustangs have 2 intake ports per cylinder, 94-98 are single port.
pres589 (djronnebaum) said:
Really need to get a copy of both wiring diagrams for both cars and make a comparison. It won't have length data or connector types shown but it should still provide basis for the differences.
The ECU is going to be different, on one end, and on the other there's controls on the engine that are different. So the stuff in the middle has to be different for this to work. A complete donor car seems like the easiest way forward OR doing a custom re-wire to support the new engine & ECU in the old chassis.
My 2 cents, I do this kind of thing on aircraft, not cars.
I'm sorry but this is incorrect. Since they are both the same engine (both 3.8's) built from the same family the stock ECU and wiring WILL work. The ECU doesnt know they year of manufacture of the engine. as long as the correct sensors are connected that the computer needs to monitor and operate the engine there should be zero reason to have to rewire the engine or upgrade the ECU to a newer one. Remember in 95 it was running an older version of OBD and did not monitor/regulate as many parameters (for example why older vehicles need a sniff SMOG check vs. just plugging into the OBD port)
Notate where the sensors and plugs are on the engine in the car and compare them to the location on the donor engine. after that everything should be gravy
The stock computer won't control the secondary intake ports, and the ignition timing tables are probably all wrong because the volumetric efficiency is going to be different.
Assuming both even use the same type of crank sensor and cam sensor. Does the old 3.8 even use a cam sensor or was it strictly batch fire/DIS?
Further research shows the 1999–2000 3.8 in the Mustang did not use IMRC, it left all 12 intake runners open at all times so there isn't a need to control the secondary intake ports. As for timing that can and should be looked at regardless either thru a hand held tuner or a dyno tune.
Further reading.. older thread but useful. Should have most of the answers you're looking by people more knowledgeable then us:
https://www.v6mustang.com/threads/sixpackstangs-official-split-port-swap-post.95288/
first post lists needed parts. note: "01-04 lowers have IMRC's in the lower intake which will need to be removed, and the holes JB welded shut since the 94-98 ECU's don't have the ability to control these. The 99-00 lowers don't have these, and therefor you will have no modding to do."
post 29 "it's a lot easier just to get a lower intake from 99-00 mustang that doesn't have them in the first place. They really don't make that much of a difference and I don't think its worth it to even bother hooking them up."
post 36 "I usually tell people to just get the IMRC delete if they want ported intakes. No one has a tried-and-true IMRC specific cam, I'm working on that but it's still in development. properly Ported & cammed parts make more low end torque than any stock 3.8, IMRC's or not. The holes left over in the runners are no big deal, I would not JBWeld them, it could fall out
and get into the motor. TIG weld it if it bothers you, but it's not a problem.
see posts 17
"You'll only need the 01 harness for scalping a few ends, other than that use the 94 harness. Once you put it back together, it's obvious what part of the harness needs modified... you just have to extend the plugs on a couple items and that is where using the spares from the 01 harness comes into play. You will need a chip to use anything other than the stock 94 injectors.
Using the 01 MAF with computer changes is a VERY bad idea, IMO. You may think it is running well, but you may be starving yourself of HP or causing damage."
42 "Yes I'm putting a 2000 engine in my 94. The 94 CPS which is bigger in dia. has 4 electrical contacts whereas the 2000 only has 2 , so I have to swap them so the 94 wiring harness will plug in. The only trouble is as I mentioned is that both top sections are attached with 2 different bolt patterns."
47 "COMPLETE ENGINE SWAP OF 99+ 3.8 INTO 94-98 For further info. re swapping complete engine into 94 to I think up to 98. see thread titled "2000 3.8 INTO 94.OXYGEN SENSORS DISCONNECTED-WHAT EFFECT?"
In reply to anger_enginering :
that's a lot of good information, thank you.
I think at this point, we are going to transfer the 95 wiring, and keep the 2000 intake/injectors, see if we can at least get it started then tune from there.
