386kustoms

iTrader: (2)

so i keep going back and forth on what im going to do here. i finally got the crossfire running good, and i think i want to keep it in the car. its a 83 daytona pace car but i really want a 5 speed. i have the opertunity to purchase a 84 trans am 5 speed that would be for parts i have done some searching on here and only found 1 person that has done a 5 speed swap in a crossfire. i messaged them but i do not think they are a member on here anymore for the post was created years ago. anyway he talked about the car surging while in neutral and had to rewire part of the computer. anyway im just looking if anyone on here has done the 5 speed swap with a crossfire and had any problems since the engine is computer controlled? besides the normal swap is there anything extra that i have to do that is related to the crossfire?

jmd

iTrader: (4)

A swap to 5spd in an ECM car isn't complete unless the PROM/BIN, park/neutral switch wiring and VSS are done correctly. In your case, the T5 needs a mechanical speedo gear setup, your VSS on the speedo will be fine, the park/neutral switch wiring needs setup like any manual trans. ECM-equipped third gen, and a manual crossfire 305 PROM should be used (did they make those?)

Surging, stalling while in neutral at road speed, incomplete operation of EGR and emissions purge systems are all indicative of an incomplete swap.

386kustoms

iTrader: (2)

thats what im trying to figure out b4 i jump into the project. they never made a crossfire 5 speed so is there a way to bypass the wiring or wire it to a different source.

TheMonster

Go carb!
Good luck on the swap, I would try to find a complete car, or jyard car to pull everything else off of, it would make the swap a lot simpler.

386kustoms

iTrader: (2)

i have accsess to a 84 trans am carb 5 speed so i will have a complete parts car. i kinda wanted to keep the crossfire setup to be different. i am not looking for power gains or racing or anything like that, i just want some fun while i drive it

TheMonster

For sure man I understand. My car was originally crossfire, but the po swapped it to carb. I think the crossfire looks pretty cool, post a pic of your motor if you can. Is your car mostly stock?

jmd

iTrader: (4)

I believe there have been a few efforts to running the CFI off a later ECM (like the very-well documented TBI '747; maybe the '746 used in the 88-92 F-bodies.)

If you do enough searching and reading on thirdgen, you'll find more detail.

As a parts car, an '88-'92 TBI 5 speed third gen could be a goldmine for you. It would have a later, better T5 and more helpful ECM and wiring parts. The '747 and '746 are very similar but have a very small number of wires / circuits that are different.

386kustoms

iTrader: (2)

the car is 100% origional and i think it would be cool if i ever showed it to have a crossfire still in it, cause hell we all know every car at the shows are chromed out w carbs and im just not into that. i realize the later trannys are better but i want to keep a mechanical speedo without buying a 300 converter. plus im not racing it or anything like that, just something fun to drive. so unless i find a good deal on a martin turbo setup its staying crossfire, there is a 88 i do belive z28 at the upull it here that was a 5 speed that still has the ecm in it. i may have to go check it out

now what is meant by a 747 ecm? is that a part number that i can find on the computer itself? even if i decide not to go that rout would it be wise for me to pick up from the z28 in the yard if that is what it has?

82tarecaro

iTrader: (4)

Contact Tom 400 CFI
He did the 5 speed swap. Although he no longer has the car, he has plenty of Crossfire knowledge and can give you some good info.

jmd

iTrader: (4)

Please keep in mind I'm not screaming that you should rip, cut and de-originalize your car.

That out of the way...I can appreciate that. I am a huge fan of factory parts that work.
Whoah whoah whoah there, speedy. What do you think was in '88 and '89 Camaros? That's right, the later T5 and mechanical speedo. The parts and time to convert an electric speedo T5 to mechanical drive are cheap and few.

Right. You want originality in appearance, a manual trans. swap and factory new-car reliability. You're not alone.

Cool.

The service number of GM ECMs identifies them for interchange and service use. 747 are the last few digits of a very common truck TBI ECM used in the later 80s and early 90s. It is one of the most popular ECMs used in TBI swaps. But, most (89-92) of the 305 TBI F-bodies used one ending in service number 746.

A thread here on thirdgen had this link: http://www.austinthirdgen.org/index.php?pid=19 which lets you look at some wiring differences. Some wires / circuits will be identical. Some will be different.

You can put a different ECM to engine harness in a thirdgen without permanently modifying anything about the car. It takes planning ahead, sometimes building a short in-between harness and other small planning bits.

But, if planned out, a later year TBI 305 ECM and harness could easily control your earlier 305 and achieve what you're seeking. It's just not going to be a 30 minute project. Nor will you get by without doing a healthy amount of reading.

82tarecaro

iTrader: (4)

I am pretty sure the T5 will run just fine off the original ECM.

386kustoms

iTrader: (2)

well thanx for all the help everyone. i usually screw around with older cars or obd2 cars that i can have the computer flashed. so even though this is old stuff its new to me. i gess i have to do some figuring b4 i jump into anything

Dens71TA

iTrader: (5)

Just retain the original automatic neutral safety switch inside the center console and use a screw driver to move the contact plate inside to the "DRIVE" selection. This makes the ECM think its in gear so the engine won't stall when pushing the clutch pedal in. You're basically doing the same thing that factory manual transmission ECM PROMs are programed to do without a switch.

I also have a complete 5-speed setup from a '84 Trans Am that I have been toying with the idea of installing in my '82 Recaro T/A CFI but with 52,000 original miles I haven't been able to get myself to cut holes in the firewall and transmission tunnel for the swap! I did a manual trans swap on my '71 Trans Am about 10 years ago and its a much more fun car to drive now.

rwallis

I just did a T5 swap in my 83 Z28 CFI. The only issue I am having is an inconsistent idle. After it warms up the IAC's seem to keep the idle between 1000 and 1300, surging between the 2. I have already replaced the coolant temp sensor and both IAC's before doing the swap. It was running great before I did the swap. I wanted to be sure of that before doing the swap. Other than that it runs great and I love the throttle response. Not throwing any codes at all and I have already replace vacuum lines previously and double checked to be sure. Base timing is correct. Getting a little frustrated. I did obtain an ECM out of an 89 TBI Camaro 5sp,1228746 but don't have a clue as to how to get it to mate with my system. Wiring is not really my specialty. Any ideas on where to go from here would be greatly appreciated.

jmd

iTrader: (4)

start reading here: https://www.thirdgen.org/forums/tbi/...-tbi-swap.html

chazman

iTrader: (4)

Tell us more about your combo. I'm planning a T5 swap in my '83 CFI as well. Which T5 do you have? What rear gear ratio?

rwallis

It is completely stock CFI. I believe the rear gear ratio of the differential is the 3:23 because when I got the car he gave me a carrier that had been replaced due to broken teeth and it was a 3:23. I believe that is what the G92 package had that year so I believe mine is the G92? I drop the clutch and it goes sideways like a posi. The T5 I got came out of a 92 camaro according to the tag on it. Don't have numbers on hand now. I am not sure how to to tell what "gear ratio" it is but I do remember that compared to other T5's in that year had a little bit taller 5th gear than others of that year. bell housing came with tranny along with slave cylinder setup and flywheel but it was for 1pc seal so I had to purchase one. Pedal assembly also came with it but was missing some supports so I had to go to pick and pull to get the rest of the parts. I believe the 83's were made for mechanical clutch linkage as the hydraulic did not want to fit through the small hole. So I had to take a die grinder and enlarge the hole and works fine. There is a factory metal plug that came out of firewall fits the hole that the shift cable came through. You have to cut out the mount for the auto shifter but I kept it just in case I decide to put back in....not. I picked up the lower boot at pick and pull also and made my hole in floor as large as I could and still adequately cover with the boot to leave more working room. The ones I saw in the junkyards were pretty big holes also. For right now I just have the shift module/neutral indicator plugged in to allow the car to start and drive and work the bugs out. there is a plug that is unplugged under the car which I believe is for the torque converter lock up. I think it tells the ecm when it is in 3rd gear and then allows the tc to lock. Have not determined if this my issue or not but I am beginning to believe it is not according auto electric guy I have been talking with but not positive. Just have to work on idle issue. My kids says the 5 speed made it seem like it has more power and a lot more fun. I will probably put some 3:73's in later but I have not even had it up to highway speed yet (currently registered on non-op). I believe it is a little tall geared right now. I believe I saw in a forum here and went to a link provided on here which told of a guy that did the mods to a newer ecm so that it would plug right into my wiring but I be damned if I can find it now. I have a wiring diagram but I am not good at wiring issues. I have been searching so many places I can't remember where I saw it. All I want to do is get it back to idling like it was and have some fun with it! If anybody has any ideas feel free to let me know. Other than that is I am glad I did it because it is more sporty and fun to drive! I will get it figure out eventually, one way or another.

rwallis

It is completely stock CFI. I believe the rear gear ratio of the differential is the 3:23 because when I got the car he gave me a carrier that had been replaced due to broken teeth and it was a 3:23. I believe that is what the G92 package had that year so I believe mine is the G92? I drop the clutch and it goes sideways like a posi. The T5 I got came out of a 92 camaro according to the tag on it. Don't have numbers on hand now. I am not sure how to to tell what "gear ratio" it is but I do remember that compared to other T5's in that year had a little bit taller 5th gear than others of that year. bell housing came with tranny along with slave cylinder setup and flywheel but it was for 1pc seal so I had to purchase one. Pedal assembly also came with it but was missing some supports so I had to go to pick and pull to get the rest of the parts. I believe the 83's were made for mechanical clutch linkage as the hydraulic did not want to fit through the small hole. So I had to take a die grinder and enlarge the hole and works fine. There is a factory metal plug that came out of firewall fits the hole that the shift cable came through. You have to cut out the mount for the auto shifter but I kept it just in case I decide to put back in....not. I picked up the lower boot at pick and pull also and made my hole in floor as large as I could and still adequately cover with the boot to leave more working room. The ones I saw in the junkyards were pretty big holes also. For right now I just have the shift module/neutral indicator plugged in to allow the car to start and drive and work the bugs out. there is a plug that is unplugged under the car which I believe is for the torque converter lock up. I think it tells the ecm when it is in 3rd gear and then allows the tc to lock. Have not determined if this my issue or not but I am beginning to believe it is not according auto electric guy I have been talking with but not positive. Just have to work on idle issue. My kids says the 5 speed made it seem like it has more power and a lot more fun. I will probably put some 3:73's in later but I have not even had it up to highway speed yet (currently registered on non-op). I believe it is a little tall geared right now. I believe I saw in a forum here and went to a link provided on here which told of a guy that did the mods to a newer ecm so that it would plug right into my wiring but I be damned if I can find it now. I have a wiring diagram but I am not good at wiring issues. I have been searching so many places I can't remember where I saw it. All I want to do is get it back to idling like it was and have some fun with it! If anybody has any ideas feel free to let me know. Other than that is I am glad I did it because it is more sporty and fun to drive! I will get it figure out eventually, one way or another.

rwallis

It is completely stock CFI. I believe the rear gear ratio of the differential is the 3:23 because when I got the car he gave me a carrier that had been replaced due to broken teeth and it was a 3:23. I believe that is what the G92 package had that year so I believe mine is the G92? I drop the clutch and it goes sideways like a posi. The T5 I got came out of a 92 camaro according to the tag on it. Don't have numbers on hand now. I am not sure how to to tell what "gear ratio" it is but I do remember that compared to other T5's in that year had a little bit taller 5th gear than others of that year. bell housing came with tranny along with slave cylinder setup and flywheel but it was for 1pc seal so I had to purchase one. Pedal assembly also came with it but was missing some supports so I had to go to pick and pull to get the rest of the parts. I believe the 83's were made for mechanical clutch linkage as the hydraulic did not want to fit through the small hole. So I had to take a die grinder and enlarge the hole and works fine. There is a factory metal plug that came out of firewall fits the hole that the shift cable came through. You have to cut out the mount for the auto shifter but I kept it just in case I decide to put back in....not. I picked up the lower boot at pick and pull also and made my hole in floor as large as I could and still adequately cover with the boot to leave more working room. The ones I saw in the junkyards were pretty big holes also. For right now I just have the shift module/neutral indicator plugged in to allow the car to start and drive and work the bugs out. there is a plug that is unplugged under the car which I believe is for the torque converter lock up. I think it tells the ecm when it is in 3rd gear and then allows the tc to lock. Have not determined if this my issue or not but I am beginning to believe it is not according auto electric guy I have been talking with but not positive. Just have to work on idle issue. My kids says the 5 speed made it seem like it has more power and a lot more fun. I will probably put some 3:73's in later but I have not even had it up to highway speed yet (currently registered on non-op). I believe it is a little tall geared right now. I believe I saw in a forum here and went to a link provided on here which told of a guy that did the mods to a newer ecm so that it would plug right into my wiring but I be damned if I can find it now. I have a wiring diagram but I am not good at wiring issues. I have been searching so many places I can't remember where I saw it. All I want to do is get it back to idling like it was and have some fun with it! If anybody has any ideas feel free to let me know. Other than that is I am glad I did it because it is more sporty and fun to drive! I will get it figure out eventually, one way or another.