305 TPI in 1984 Cutlass suprime 3.8v6

[Mayronus]

Hello
I need little help with my swap.
Im swaping TPI engine with th700 in my Cutlass 84 3.8 v6.
I already have gas tank and sending unit from 4.3 TBI custom fuel lines also.
I bought this stand alone wiring harnes :
http://www.larryselectricsite.com/TPI.html
And the problem is what to do with Cutlass ecm and harnes ?
Should I just remove the old ECM ?
What should I remove and what should stay ?
Any one have cutlass wiring diagrams ?
Thank You

 

[TURNA]

Hello
I need little help with my swap.
Im swaping TPI engine with th700 in my Cutlass 84 3.8 v6.
I already have gas tank and sending unit from 4.3 TBI custom fuel lines also.
I bought this stand alone wiring harnes :
http://www.larryselectricsite.com/TPI.html
And the problem is what to do with Cutlass ecm and harnes ?
Should I just remove the old ECM ?
What should I remove and what should stay ?
Any one have cutlass wiring diagrams ?
Thank You

the best thing to do is go through it wire by wire if you are not sure what to remove.
follow the harness from the existing computer and work your way around it
most of it is good to go but i think the A/C may tie into it somewhere

 

[85 Cutlass Brougham]

Everything will work fine if you remove the Cutlass computer harness. It unplugs with 2 plugs under the far passenger's side of the dash. I run my car with that removed and have lost no function other than torque converter clutch engagement. From there, you will need to know the pin outs of both the Camaro and Cutlass harnesses and make one mate with the other. The plugs may or may not be the same, and may or may not have the same pin outs. Just don't hack the Cutlass harness as you may need something off of it. I would also look into replacing the Th700 R4 with a G body native TH 200 4R as it will be easier to make it work in the G body. (it uses the same driveshaft as the TH 200C) Plus, it has a better ratio spread. You will also want a better rear axle ratio, unless you have the code GU4 3.23 axle, which will be fine. If it is a GU1 2.41, it needs to go. (Codes can be found on the Service Parts ID label under the trunk lid)

I will also say that you will need to figure out how to give the A/C idle speed compensator the proper signal in this install. It may need a 5 volt signal and not the 12 volt signal native to the V6 Cutlass.(Remember: most all reference and other signals given off by a modern EFI ECU are 5 volt.) Also, I imagine the VSS will use the same signal in a G body as it does in a Camaro. What would worry me is if the Camaro harness is set up for Pass Key. If so, you may have to adapt part of the Camaro column along with the lock cylinder and key to the G body column. As both use Saginaw columns, this should be fairly academic in nature and more time consuming than anything. Do not forget to get a high pressure fuel pump too! The TBI pump runs on around 9psi, while the TPI needs something like 50psi.

For schematics, I do have them but they are too complicated to post in one section. Go on E-Bay and buy a complete 1984 Cutlass Supreme factory service manual set. It will be invaluable in sorting out your hybrid creation.

 

[TURNA]

the person you bought the harness from should have a chip that goes along with it that bypass's the pass key. If they dont I would return it and look for another harness company that sells everything.

When I did this conversion years ago to one of my 80 Malibu's non A/C car, I got my harness and chip from TPI TECH in CT. But I don't think they are around anymore.

 

[Mayronus]

Everything will work fine if you remove the Cutlass computer harness. It unplugs with 2 plugs under the far passenger's side of the dash. I run my car with that removed and have lost no function other than torque converter clutch engagement. From there, you will need to know the pin outs of both the Camaro and Cutlass harnesses and make one mate with the other. The plugs may or may not be the same, and may or may not have the same pin outs. Just don't hack the Cutlass harness as you may need something off of it.

Ok so i pull cutlass engine wiring inside then remove Cutlass ECM, disconect pin from brake switch and connect it to my stand alone harnes.
Next just hide old wiring harnes under the dash 8)

Im little worry about engine oil pressure sender because my stand alone
wiring harness don't have conector to that sensor, and as far as i know that sensor is needed for fuel pump ??
I dont have also:
Fan relay Trigger
A/C recognition
Park Neutral wire

Should I add those extra wires ??

I would also look into replacing the Th700 R4 with a G body native TH 200 4R as it will be easier to make it work in the G body. (it uses the same driveshaft as the TH 200C) Plus, it has a better ratio spread. You will also want a better rear axle ratio, unless you have the code GU4 3.23 axle, which will be fine. If it is a GU1 2.41, it needs to go. (Codes can be found on the Service Parts ID label under the trunk lid)

I allready put engine in with TH 700RR4 And i have driveshaft from camaro. I bought 3.42 richmond gears + Truetrac LSD + Ratech Complete Ring and Pinion Installation Kits 8)

I will also say that you will need to figure out how to give the A/C idle speed compensator the proper signal in this install. It may need a 5 volt signal and not the 12 volt signal native to the V6 Cutlass.(Remember: most all reference and other signals given off by a modern EFI ECU are 5 volt.)

I have A/C compressor from Cutlass and from Camaro
So Cutlass ECU is giving signal to A/C ? Any ideas how to sort it out?

Also, I imagine the VSS will use the same signal in a G body as it does in a Camaro. What would worry me is if the Camaro harness is set up for Pass Key. If so, you may have to adapt part of the Camaro column along with the lock cylinder and key to the G body column. As both use Saginaw columns, this should be fairly academic in nature and more time consuming than anything. Do not forget to get a high pressure fuel pump too! The TBI pump runs on around 9psi, while the TPI needs something like 50psi.

I can't use vss from Cutlass because its using 2000 pulses
and speed density TPI need 4000 pulses. I have VSS that can supply 4000 pulses and can drive speedometer cable.
http://www.jagsthatrun.com/Pages/SpeedS ... gralsleeve

No need to worry about vats, egr,smog pump etc.. My friend will burn me custom chip and we tune car as well.
As for fuel pump i've got Walbro 255 lph
Thx

 

[drknow90rs]

You will need to see al least 43 Psi at the fuel rails. The wlbro 255 is an excellent pump and you will have no problems there. I run that same pump on my '86 IROC-Z. As for wiring diagrams for the TPI you can find them here: www.thirdgen.org
Good luck!

 

[Mayronus]

OK
I need a little help with wiring.
Im installing Megashifter, i have column shifter in My Cutlass:
Acordingly to this installation instruction :
www.bmracing.com/bmracing/installation_ ... tion/8.pdf

Wires in Cutlass have the same colour code as in Camaro??
Neutral Wires : PURPLE and YELLOW
Reverse light : DARK/BLUE and LIGHT GREEN
ECM: ORNG/BLACK
BLK/WHT ??????????????????

NEXT
TCC LOCKUP wire in Cutlass going from ECM to Breake swich is WHITE ??
IN Camaro is TAN/BLACK ?????

A/C wires:
Camaro wire code Dark Green it's going to A/C power to A/C clutch,
which is in cutlass dark green as well ??????

Camaro Fan request signal from A/C in camaro GRAY in Cutlass??????

Camaro Fan control relay wire is dark green/white going to fan relay ??

Can anyone confirm that wirings are correct and PLEASE let me know ????