#1 what rpm is the 2.8 turning at 70mph in 5th gear?
I read somewhere that I'd need a 5spd harness from a v6 to make everything work, I have an 87 GT as a donor, but it has an automatic transmission #2 could I adapt the harness from the 87 donor with the harness out of the 2m4 to make a functional harness? (Id need the pinouts for the 2.8 ecm connectors to figure out what Im pulling from the 2.8/auto harness and putting in from the 2m4 harness)
I already know to use the isuzu throwout bearing, and use a v6 clutch, and to swap over the v6 gauges.
#1. From memory, I think mine ran about 2200-2500 at 70 mph.
You would need a V6 manual transmission harness. Doesn't necessarily have to be from a 5 speed equipped engine. There is no provision for the backup lights on the 4-speed equipped engine harnesses so that would have to be wired in.
You will need a manual transmission V6 ECM.
#2. You probably could, but it might require a lot of work. Time is money. Try to pick up a correct engine harness in The Mall.
#1. From memory, I think mine ran about 2200-2500 at 70 mph.
You would need a V6 manual transmission harness. Doesn't necessarily have to be from a 5 speed equipped engine. There is no provision for the backup lights on the 4-speed equipped engine harnesses so that would have to be wired in.
You will need a manual transmission V6 ECM.
#2. You probably could, but it might require a lot of work. Time is money. Try to pick up a correct engine harness in The Mall.
My 86 4-speed car had a pigtail for the reverse lights in the engine bay, even though it was unused. When I swapped in an F23 I used those wires with a different pigtail and the reverse lights work as expected.
What's different about the auto harness vs. manual?? Probably only the trans related pigtails. Shouldn't be too hard to change an auto harness to manual. Delete the TCC and whatever other 'auto' wires are there and add the wires for reverse lights. Change the pigtail for the speedo if necessary.
As far as the harness goes, I am going to strip all the old tape and conduit off and ohms test each wire, and then wrap it up with new tape and conduit.
I will remove the tcc wiring from the auto harness at the ecm connector pin (completely and cleanly remove it) I'm not entirely sure what wiring goes to the manual trans, I'll have to see what wiring is going to my 2m4's isuzu, but I'll try to transfer it over to the harness I will use.
I just need the pinout chart for the manual v6, versus the auto v6, since the 4 cyl wiring plugs into the ecm on the side and not the bottom like the 6cyl harness.
the ecm's by design were not different, or were they? I'm going to mod the motor anyways, and will get the prom chip re-programed (egr programing delete, eliminate the high idle on cold starts, and program the warm idle a little lower, adjust open/closed loop fan on/off temps)
As far as the harness goes, I am going to strip all the old tape and conduit off and ohms test each wire, and then wrap it up with new tape and conduit.
I will remove the tcc wiring from the auto harness at the ecm connector pin (completely and cleanly remove it) I'm not entirely sure what wiring goes to the manual trans, I'll have to see what wiring is going to my 2m4's isuzu, but I'll try to transfer it over to the harness I will use.
I just need the pinout chart for the manual v6, versus the auto v6, since the 4 cyl wiring plugs into the ecm on the side and not the bottom like the 6cyl harness.
the ecm's by design were not different, or were they? I'm going to mod the motor anyways, and will get the prom chip re-programed (egr programing delete, eliminate the high idle on cold starts, and program the warm idle a little lower, adjust open/closed loop fan on/off temps)
There shouldn't be any manual-related wiring going to the ECM, except for the shift light wire from the ECM to the tach. I believe the shift light wire is the same wire that's used for TCC with autos. You should be able to un-pin the one from your 4-cylinder harness and pin it into the V6 harness.
I'm not sure how the reverse lights circuit is routed on auto cars but I'm guessing it uses a shifter-mounted switch. If that is the case you'll probably have to cut the reverse lights wires that go into the car and splice them to the reverse lights wires from the 4-cylinder harness.
The speed sensor may use a different pigtail on auto cars; if that is the case just splice in the connector from the 4-cylinder harness.
If you're getting the chip re-programmed, you do not need a different ECM. The auto ECM will be just fine.
[This message has been edited by bcampbell (edited 01-21-2014).]
I thought the ECMs were different, mine does around 3000rpms at 80. My Isuzu has been holding up pretty well to all the burnouts and hard acceleration in second, especially because it came from behind a 200000mile duke before I did the swap and leaks all the transmission fluid out so it is running maybe at a quarter the amount of fluid it should have. I think the isuzu has pretty crappy ratios for performance with the 2.8, I plan on swapping an f23 soon.
Anyways when I did the swap I got the ECM and harness from a 5 speed, had to change the fuel lines/relocate fuel filter, fuel pump, finagle the cooling lines since I did not have a crossover tube for coolant, I used standard heater lines for the heater, extra fuse in the injector slot, and make sure you get the right motor mount because I accidentally bought one for an 88 and had to make a new mount on the cradle to make it work.
When you replace the fuel pump you need to use a special high pressure submersible fuel line. It is rare to find, you can get it at NAPA. When I first installed the pump, the high pressure busted right through the stock coupler. I have since used regular high pressure fuel line to do it but the gasoline eats at the line in the tank and I need to get the submersible line as well.
And I suggest putting in the v6 tach like you are planning, I modified my 4cyl tach first but it was annoying to have it work consistently probably because the micro-pot I bought to do it was uh real cheap
Good luck it is a big improvement! And the stock exhaust without the cat sounds really nice.
Hey Zach, yeah, I guess I'm pretty lucky to have a complete donor car sitting here to swap in what I need. I'm going to overhaul the 2.8 with new bearings and a custom cam and port everything, so it should pull nicely...
I already have the $30/Ft. submersible fuel line from NAPA, aparrently that's the only place that sells it!!! each oe in-tank fuel line replacement job takes about 1.5" I've done 6 so far and have a little left to do this one up too.
I'm going to swap over the gauge cluster from the GT and the auxilliary as well.
and right now im running straight pipes on my d/d 86 gt, so I KNOW all about the sound, lol. I also have a nice oe exhaust setup from an 85 V6 SE, and I'll delete the cat, for better flow and tone.
EDIT: Zach, I'll contact you later, I have some more questions for later concerning your swap, and I think you can help me out.
[This message has been edited by AL87 (edited 01-22-2014).]
My reference to obtaining a manual V6 ECM was to indicate that an automatic ECM won't run a manual transmission equipped car. And yes, the 86 V6's had the pigtail just hanging in the 4-speed equipped cars. The 85 V6 harness didn't have that and therefore the backup lights would have to be wired to the console harness or rewired to the transmission switch.
My reference to obtaining a manual V6 ECM was to indicate that an automatic ECM won't run a manual transmission equipped car. And yes, the 86 V6's had the pigtail just hanging in the 4-speed equipped cars. The 85 V6 harness didn't have that and therefore the backup lights would have to be wired to the console harness or rewired to the transmission switch.
so... there is a difference beween the actual ecms? or can I just get the prom reprogrammed? there is a second smaller chip, what is that for?
so... there is a difference beween the actual ecms? or can I just get the prom reprogrammed? there is a second smaller chip, what is that for?
There is a difference in their abilities to control one another. I don't know what that internal difference is. Whether it's in the chip or the main board. I can't find the PCM in the P22 book.
There is a difference in their abilities to control one another. I don't know what that internal difference is. Whether it's in the chip or the main board. I can't find the PCM in the P22 book.
