TBI to Vortec Swap question

[iluvmy72]

If you did or know anyone that has done this....please post a reply with some info....I'd like to know how he got the dash and stuff to hook up.

[tvblazer78]

I may have to move you to drive tran, but I will give it some time..

Can anyone help?

[clinebarger]

What year vortec engine are you going to use? What tranny? what truck do you have? you can use your factory sendors for oil& temp (genIII 4.8 5.3 6.0 require drilling & tapping) The speedo is more compilcated depending on what you have.I vote GENIII the 5.3 in my suburban made it feel like a new truck.

[hjedge]

What year vortec engine are you going to use? What tranny? what truck do you have? you can use your factory sendors for oil& temp (genIII 4.8 5.3 6.0 require drilling & tapping) The speedo is more compilcated depending on what you have.I vote GENIII the 5.3 in my suburban made it feel like a new truck.

did you use adapters and stock motor mounts? and transfer case mounts?

[clinebarger]

I did use adapters from street & performance and stock mounts. mines not
four wheel drive. what truck do you have? Advance Adapters has a kit to bolt a earlier tranny to a gen III.

[hjedge]

1990 with tbi 350/700r4 but want change motor and tranny

[clinebarger]

your transfer case will not bolt up to a gen III 4L60E it has 6 bolts on the tail shaft housing. the 700R4/4L60 in your truck has 4. the front drive shaft on your 90 is on the right. the later model stuff is on the left. ive never converted a 4WD before. maybe someone on the board has.

[iluvmy72]

cinebarger.....tell us more about these adapters you got. And I have installed the 97 7.4 motor already into the 91. But it needs a wiring job from the ECM. I currently have the 700r4 hooked to the motor via a flex plate. But I'm considering tossing it and going with a 4L80E from that year to make it easier on the ECM. But then again I'm told all I need is a modified harness and a "lock-up" kit for the 700r4.

[clinebarger]

I was only talking about gen III & IV motors ( 4.8 5.3 6.0 6.2 LS1 LS2 etc.) needing a adapter kit (crank to converter hub spacer & a redrilled flexplate)

your vortec 7.4/4L80E came with a 6 bolt converter instead 3 thats the only reason i can think of for you needing a flexplate for the 700R4.

go with the 4L80E. A stock 700R4/4L60/4L60e will NOT hold behind a big block.

If you need help with the wiring let me know.

[iluvmy72]

yes I could use some help. I have a 1991 4wd Suburban I have installed in it a 1997 454 vortec. It has the harness and the ECM from the 197 as well. I will be putting in the 4L80e from a 1994 setup(TBI)...I'm told I'll need a custom Harness from a place like Howell to make it work. But my question is about the other stuff from the dash. Like the A/C, speedo, temp gage, oil lights.etc....how do they hook up? same thing with the tranny. What would I need to make that one from the 94 work? And what about the suspension....if you get the feeling that I'm lost...well....I am.

[clinebarger]

let me look up some stuff and i will get back to you. ill try to post some diagrams & pin outs.

[clinebarger]

heres some pinouts. hook pin 4 to an ignition hot.

[clinebarger]

dont have to mess with any of these.

[clinebarger]

make sure pins 17&18&19 are grounded (the black wires with eyelets on them need to be grounded to the block). pin 21 to fused battery hot(constant)
for pcm memory.

[clinebarger]

pin 1 to fuel pump relay (it sends 12 volts to activate the relay) do not try to run the fuel pump directly off this wire pcm faluire will result.

pin 4 goes your speed signal buffer (under your dash) to run the speedo and cruise module (this may or may not work or the speedo will be way off) I will post some more diagrams for this later

pin 5 will go to the check engine light bulb

pin 10 goes to your brake light switch the switch has 4 wires. hook it to the
pink&white wire (not the pink wire) this tells the pcm when your brakes are applied to unlock the torque converter.

pin 11 goes to the dianostic connecter ( you will need a OBD II connecter)
i will give diagram for this too.

pins 13& 18 will go to a ignition hot.

[clinebarger]

pin 11 of the black pcm connecter will go to pin 2 of the dianostic connecter

4&5 to a groud

13 to a battery hot(constant)

[clinebarger]

Your 97 pcm should run a 94 4L80E with no problem. you need to use your 90 model senders on the 97 engine (oil &temp) On the a/c the only thing that your changing are the compressor and lines. use the wire that was powering your old compressor. you will have to have custom ac hoses made.

as far as the suspensoin if it was a small block truck you may need big block springs under the front.

[clinebarger]

11

[clinebarger]

heres a diagram of the speed signal buffer.

[glock35ipsc]

Originally Posted by clinebarger

11

Do you have a bigger pic of this drawing?

[glock35ipsc]

Originally Posted by clinebarger

heres a diagram of the speed signal buffer.

No diagram shown, could you post this one up please?

Thanks for posting these!!

[clinebarger]

still looking for a better pic. but heres some information that might help.




The Vehicle Speed Sensor (VSS) Buffer is a solid-state device that is used to change the signal from the speed sensor to a digital signal. The VSS buffer will change the signal from the speed sensor to a signal containing 4000 pulses per mile for the instrument cluster.

The VSS buffer is matched to the final drive and tire size of each vehicle. It must be replaced with the proper buffer to match the final drive and tire size of that vehicle.

CAUTION: If the final drive or tire size is changed for any reason, the buffer must also be changed to continue to produce an accurate speedometer/odometer reading. The incorrect buffer will also affect the anti-lock brakes, engine control module, and cruise control module.

[clinebarger]

this the best i can do

[clinebarger]

heres another one i hope it will be clear. the previous diagram leaves some curcuits out.

[clinebarger]

i can read it on my computer but it gets fuzzy when i post it? try saving it to your pictures so you can enlarge it,