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My 5.3 swap thread!

So my questions are as follows,

EDIT: questions also follow the list/pic format above.

1. What do i do with the orange and grey wires from the plug? Are they needed?

2. What the heck is this wire? I dont even remember un plugging it.

3. This ground goes over to the driver side. Does it need grounded or is it a ground supply?

4. Ign hot as it was listed on my diagram. This can be eliminated entierly right?

5. C9 "Crank input" this can be eliminated entierly right?

6. D6 "ign bypass out" this can be eliminated entierly right?

7. B8 A/C on. Can this be eliminated? I plan on doing ac in the future. Is this just a hot lead going to the ecm when the AC is on to kick idle up?

8. A/C wire. No real info needed here yet.

9. B2 "fuel pump input" I would like to retain my factory fuel pump relay. Is eliminating this wire going to effect me in some way with the whole oile pressure switch setup?

10.TSS wire. This can be eliminated entirely right?

11.The orange wires had several going to random sensrs and such with the last one going to the fuel pump relay. Does this need re connected to the fuel pump relay?

12.The grey wires were the same aas the orange. one lead in from the dirver side and spliced to go about 4 or 5 different ways. One went to the fuel pump relay Do i need to re connect it to the relay?

13.o2 sensor wire. This will be eliminated entierly.

14.A7 goes from the computer to the th400 kickdown relay. Im thinking i can hook it back up once i install one of those older style throttle pedel actuated units so it will stay for now.

15.Is just a pic of the other plug that was in the interior right next to the two computer plugs.

16.B10 "park/neutral input" Do i need to hook this up to the new ecm?

17.A5 "Check engine light" to be hooked up to the output from the new ecm.

18.Ground. Again, I dont know if this needs ground or supplys ground.

19.A10 "vss input" This would go to the new computer.

20.Orange and white wires. Dont remember now what they were for but it was something i decided was not needed for the new computer.


:eek1:
 
Here is the diagram i was working off of.

wireTBI-1990b.gif
 
Is the wire in pic 2 the one behind the booster? I see the master cylinder behind there. If so that one looks Identical to the timing one on mine
 
1. The orange and grey wires from the oil pressure switch was used to activate the fuel pump in parallel with the TBI ECM's fuel pump relay. The orange wire goes to fused battery power, the grey wire went to the fuel pump. Your 5.3L will not need these wires anymore so you can just toss the connector and trim the orange wire back to the splice in the harness.
2. Where does this wire exit the harness? Behind the engine?
3. Put a crimp on ring end onto this wire and ground it if it is infact a ground. The 5.3L harness has it's own grounding and shouldn't require any splicing into your truck's original harness. Be sure it is a ground by checking resistance to ground with a multimeter. If it is around 1 or 2 ohms, then ground it.
4. Pink wires with a black stripe are always ignition wires. You can feed this wire into your 5.3L harness on the ignition input wire.
5. Yup, your TBI ECM wanted to know when the starter solenoid was activated. The 5.3L doesn't care.
6. I don't recall what this particular wire is used for... I'll look into it.
7. If this is the wire from your HVAC controls, it will be fed into the new PCM to control the AC compressor.
8. Delete this wire, the 5.3L controls AC different than the older trucks and all new engine wiring will be required.
9. As mentioned in 1. delete this wire and the oil pressure switch.
10. If your harness comes with VSS wiring, then go ahead and pull these wires right out. If not, you'll need them to tie into the PCM. You can delete the DRAC under the dash as well. The PCM handles that now.
11. This is a battery power source. One lead goes to the fuel pump relay, one to the pressure switch and the smaller ones go up to the old ECM. You'll need to power the PCM with this feed.
12. This is the fuel pump feed wire. One goes to the ECM in the TBI harness, one goes to the fuel pump, one goes to the pressure switch. The other side goes back to the fuel pump. You'll only need one run up to the fuel pump relay.
13. Yup, delete.
14. The 5.3L won't have an output for the TH400. You'll need to hook this wire up a 12V ignition source (pink/blk wires) so the TH400 will downshift properly.
15. If that plug is the clear one just to the left of the ECM, it contains the SES light, park / neutral signal, speed signal from the DRAC, ALDL wire, etc.
16. If your PCM is programmed to handle a manual transmission, then nope! If not, then it will need to be hooked up. This should be grounded when the truck is in park or neutral.
17. Yup, hook this wire right up to the new 5.3L harness. Both the TBI ECM and the Gen III PCM provide the ground for the light.
18. This one is a ground supply to the old ECM. Just clip this wire or ground it as the new harness should provide it's own grounding.
19. Delete this wire. It runs from the DRAC and carries a 2k ppm signal to the old TBI ECM. You will need to run a new wire from the PCM up to your speedometer and install a pull up resistor circuit to have the factory speedometer work properly.
20. Orange would be battery power. I am not 100% what the white wire would have been...
 
Heres a photo of how my down pipe is cut and turned to clear the frame. Also how many wires do you have coming out of the 5.3 harness that need to be hooked up?
IMG_4303.jpg
 
Ah yes the exhaust pics. Here ya go. I tried like hell to get good pics, but here is what i got instead...

Driver side!

IMAG0460.jpg


IMAG0461.jpg


IMAG0462.jpg


IMAG0465.jpg


IMAG0466.jpg


IMAG0467.jpg


IMAG0468.jpg


IMAG0469.jpg


IMAG0472.jpg


IMAG0477.jpg
 
texas4x4rebel said:
Heres a photo of how my down pipe is cut and turned to clear the frame. Also how many wires do you have coming out of the 5.3 harness that need to be hooked up?
Click to expand...

Thanks for the pic! I technically only have four. Bat, ign, ground, and fuel pump. But i also have to hook up vss, check engine light, and a couple other things.
 
Its up to you, but i'd pull those factory exhaust studs out of the manifolds at the y pipe connection, and drill out and replace with bolts. I HATE breaking these when doing exhaust removal. I'd much rather break a bolt, or use a grade 8 that i can loosen, rather than deal with breaking studs in a location that i can't drill them out.

Drill them out when you have them on the bench, and eliminate that problem forever....
 
Honestly i hadnt thought about that. It is a good idea though. Might have to do it. Thanks for the suggestion!
 
Its hard enough to fix broken ones on a stock rig, yours looks like they will be inside the frame rail.....

Might as well eliminate the point of failure now, when you can get to it.
 
Couple clearification questions.

Russell said:
1. The orange and grey wires from the oil pressure switch was used to activate the fuel pump in parallel with the TBI ECM's fuel pump relay. The orange wire goes to fused battery power, the grey wire went to the fuel pump. Your 5.3L will not need these wires anymore so you can just toss the connector and trim the orange wire back to the splice in the harness.

I would like retain the stock oil pressure sending unit and guage. By leaving the tan wire only in the connector and plugging it back into the sending unit, would i be good to go? This motor had the oil pressure sending unit/oil pressure fuel switch in one.

2. Where does this wire exit the harness? Behind the engine?

I dont remember now. I'll check it in the morning.

3. Put a crimp on ring end onto this wire and ground it if it is infact a ground. The 5.3L harness has it's own grounding and shouldn't require any splicing into your truck's original harness. Be sure it is a ground by checking resistance to ground with a multimeter. If it is around 1 or 2 ohms, then ground it.

So if its 1-2 ohms i need to ground it? What if i come up with a different reading? Would it mean that it is already grounded?

4. Pink wires with a black stripe are always ignition wires. You can feed this wire into your 5.3L harness on the ignition input wire.

The dude that hooked me up the harness told me to use my old coil wire to do this sense its a heavy guage wire that originally went to the coil. Does that sound ok to do that and get rid of this wire?

5. Yup, your TBI ECM wanted to know when the starter solenoid was activated. The 5.3L doesn't care.
6. I don't recall what this particular wire is used for... I'll look into it.
7. If this is the wire from your HVAC controls, it will be fed into the new PCM to control the AC compressor.

I plan on either retrofitting my old compressor or using a sanden pump. Can i just wire it off the truck and leave the ecm out of it? Or will i need to let it know that the ac has been activated?

8. Delete this wire, the 5.3L controls AC different than the older trucks and all new engine wiring will be required.

Kinda the same as 7.

9. As mentioned in 1. delete this wire and the oil pressure switch.
10. If your harness comes with VSS wiring, then go ahead and pull these wires right out. If not, you'll need them to tie into the PCM. You can delete the DRAC under the dash as well. The PCM handles that now.

Sorry, this one was actually TSS wire. timing by pass deal.

11. This is a battery power source. One lead goes to the fuel pump relay, one to the pressure switch and the smaller ones go up to the old ECM. You'll need to power the PCM with this feed.

Dude also gave me instructions to power the pcm with the junction block on the fire wall. What say you?

12. This is the fuel pump feed wire. One goes to the ECM in the TBI harness, one goes to the fuel pump, one goes to the pressure switch. The other side goes back to the fuel pump. You'll only need one run up to the fuel pump relay.

So after all the clipping, one wire should remain and it should run down along the frame rail and should be the one that is one the side opposite my hand right?

13. Yup, delete.
14. The 5.3L won't have an output for the TH400. You'll need to hook this wire up a 12V ignition source (pink/blk wires) so the TH400 will downshift properly.

So is my understanding that this A7 was a signal sent out by the ecm telling the realy to switch and therefore tell the trans to kick down incorrect? Or is this wire simply letting the ecm know that the tranny is set to down shift?

15. If that plug is the clear one just to the left of the ECM, it contains the SES light, park / neutral signal, speed signal from the DRAC, ALDL wire, etc.
16. If your PCM is programmed to handle a manual transmission, then nope! If not, then it will need to be hooked up. This should be grounded when the truck is in park or neutral.

I will have to ask but i think its set for manual so i will just leave it alone for now.

17. Yup, hook this wire right up to the new 5.3L harness. Both the TBI ECM and the Gen III PCM provide the ground for the light.
18. This one is a ground supply to the old ECM. Just clip this wire or ground it as the new harness should provide it's own grounding.
19. Delete this wire. It runs from the DRAC and carries a 2k ppm signal to the old TBI ECM. You will need to run a new wire from the PCM up to your speedometer and install a pull up resistor circuit to have the factory speedometer work properly.
20. Orange would be battery power. I am not 100% what the white wire would have been...

I forgot what they were but i remember knowing that they were obviously not needed. Oh i think one was serial data. obviously not needed anymore...
Click to expand...
 
So im thinking i should probably have the wiring done tomorrow and the next day. After that i want to go ahead and do the fuel pump this weekend i think. Then next week, do the exhaust and just start putting it all back together. Possible test fire next weekend but im not trying to set my sights so high that i end up rushing to finish stuff.
 
The answer to #4 is what I did I hooked up my coil wire to the keyed 12v source into the 5.3 pcm.

Also I remembered what I did to make the exhaust clear on the driver side when I cut it off at the flange I flipped it 180 degress and cut the curved end so that it would clear the frame. Yours looks to be cut off pretty short but you can still see that it curves a little on the opposite side from the manifold.
 
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