Big Blue's Transformation

[ArdWrknTrk]

I don't think you said that. And I didn't mean to imply that you did. But you were saying I should ground the ECU to the engine ground at the firewall, so that's why I added that pic.

It is a LOT of stuff under the hood. Man, a whole lot. I didn't realize that when I started this. It really makes you think. But I hope I'll like it.

As for when it'll be back on the road, I'll say "soon". I'm hoping it'll be in April, meaning in the next two weeks. Thinking while I type, here's what I think I have to do:

• A minor change to the power wiring to do, which is move the feed from the passenger's side to the new PDB and make a jumper to go from the PDB to the battery isolator.

• Install the air cleaner box and hook up the MAF & IAT sensors. Should be easy as it has all been together before.

• Install the intake air plumbing. Again, that should be quite easy as it has been on before as well.

• Set the timing per Bill's directions.

• Test the new power wiring to ensure that it won't smoke. I think I can do that by using the lab power supply, which only provides 1A so can't smoke anything.

That begs the question of what to do next. Do I go for broke and fire the whole thing up and see if it'll run? Or do I go through and test things that have just now been connected to the PDB/ECU wiring - which has itself been tested.

Thoughts?

I think what I said was that I don't trust sheet metal to carry a critical ground, and that if I had my pcm grounded to the firewall I would want it connected to the engine too.

If you have any question, then I think you should test.

Ironically it's always when I have NO DOUBT that things go sideways..

[Gary Lewis]

I think what I said was that I don't trust sheet metal to carry a critical ground, and that if I had my pcm grounded to the firewall I would want it connected to the engine too.

If you have any question, then I think you should test.

Ironically it's always when I have NO DOUBT that things go sideways..

Yep, that's what you said. So we aren't trusting sheet metal. Just good old copper, and lots thereof.

But I forgot one crucial thing in the to-do list - the O2 sensor cable. Not a big deal and I have all of the bits and pieces, just need to do it. And run the cable for the AEM O2 sensor, although it won't be installed until I weld a bung in, and I want someone better than me to do that.

As for testing, what I have tested is everything from the ECU's connector to all of the connectors radiating off of the PDB. But that means that the engine harness and the to-be-built O2 sensor harness haven't been tested. So for peace of mind I need to test them, although presumably the engine was running when the truck was taken to the salvage so the engine harness should be good. However, knowing that injector #1 has both power and connectivity to the right pin on the ECU's connector would be comforting. Ditto the other injectors, ECT, IAC, TPS, etc.

So I think I'll do the power wiring changes tomorrow, make the O2 cable, and add the air filter box and the connectors to it. But I'll leave the inlet tubing off as that makes access to the top of the engine a lot better.

Then I'll test the power circuits, honk the horn, tap on the brake and see that the ECU gets BOO'd, etc. And once that is done I'll start testing the engine harness.

[Gary Lewis]

Yep, that's what you said. So we aren't trusting sheet metal. Just good old copper, and lots thereof.

But I forgot one crucial thing in the to-do list - the O2 sensor cable. Not a big deal and I have all of the bits and pieces, just need to do it. And run the cable for the AEM O2 sensor, although it won't be installed until I weld a bung in, and I want someone better than me to do that.

As for testing, what I have tested is everything from the ECU's connector to all of the connectors radiating off of the PDB. But that means that the engine harness and the to-be-built O2 sensor harness haven't been tested. So for peace of mind I need to test them, although presumably the engine was running when the truck was taken to the salvage so the engine harness should be good. However, knowing that injector #1 has both power and connectivity to the right pin on the ECU's connector would be comforting. Ditto the other injectors, ECT, IAC, TPS, etc.

So I think I'll do the power wiring changes tomorrow, make the O2 cable, and add the air filter box and the connectors to it. But I'll leave the inlet tubing off as that makes access to the top of the engine a lot better.

Then I'll test the power circuits, honk the horn, tap on the brake and see that the ECU gets BOO'd, etc. And once that is done I'll start testing the engine harness.

I decided I'd start with the O2 cable, and that's as far as I got, although I did get it done and installed. But not w/o a bunch of head scratching.

The issue was that the '96 EVTM doesn't have the pinouts for the connectors going to the O2 sensors. And while I have a connector that plugs into C101, it isn't the right one for this application and had very different wire colors. Plus I was using O2 extension cables for their connectors to mate to the O2 sensors, and they have their own wire colors. And the O2 sensors themselves have different wire colors. So I had a whole bunch of wire colors and and was going bonkers.

However, I did remember that I have another harness and, fortunately, it has O2 connectors on it. So I was able to determine what wires went to what pin in the connectors. And then I mapped out this: (Sorry for the smudges, a whole lot of erasing went on today as I worked through this.)

And with that I was able to put the cable together shown below. It is now installed, but that's a bit of a story as well since I wasn't sure how I wanted to run the cable to the sensors. But in the end I decided to run it across to the engine with the harness from C101, back along the side of the valve cover, and then down over the back of the engine on each side. So in the pic below you see that there's no convolute on part of the cable, and that's because that section is covered by the heat-reflective covering, and it is just barely big enough to handle the two cables w/o a covering on them.

So now it is not only done but installed and I can move on to the last few things tomorrow.

However, I'm in a conundrum about my AEM AFR meter. Looking today the first place the two sides of the exhaust come together is right under the rear edge of the cab. And even then there's very little, if any, place to tap into in order to "see" both banks. So it looks like I'll have to tap into one side or the other instead of both

[85lebaront2]

I decided I'd start with the O2 cable, and that's as far as I got, although I did get it done and installed. But not w/o a bunch of head scratching.

The issue was that the '96 EVTM doesn't have the pinouts for the connectors going to the O2 sensors. And while I have a connector that plugs into C101, it isn't the right one for this application and had very different wire colors. Plus I was using O2 extension cables for their connectors to mate to the O2 sensors, and they have their own wire colors. And the O2 sensors themselves have different wire colors. So I had a whole bunch of wire colors and and was going bonkers.

However, I did remember that I have another harness and, fortunately, it has O2 connectors on it. So I was able to determine what wires went to what pin in the connectors. And then I mapped out this: (Sorry for the smudges, a whole lot of erasing went on today as I worked through this.)

And with that I was able to put the cable together shown below. It is now installed, but that's a bit of a story as well since I wasn't sure how I wanted to run the cable to the sensors. But in the end I decided to run it across to the engine with the harness from C101, back along the side of the valve cover, and then down over the back of the engine on each side. So in the pic below you see that there's no convolute on part of the cable, and that's because that section is covered by the heat-reflective covering, and it is just barely big enough to handle the two cables w/o a covering on them.

So now it is not only done but installed and I can move on to the last few things tomorrow.

However, I'm in a conundrum about my AEM AFR meter. Looking today the first place the two sides of the exhaust come together is right under the rear edge of the cab. And even then there's very little, if any, place to tap into in order to "see" both banks. So it looks like I'll have to tap into one side or the other instead of both

See if these help any. The VPWR is the red wire (circuit 361) HO2S heater is the control circuit to the EEC (circuit 387 on right bank, circuit 388 on left bank) HO2S signal is the output to the EEC (circuit 74 on right bank, circuit 94 on left bank) SIG RTN is the low side and goes to the gray with red wire (circuit 359).

[Gary Lewis]

See if these help any. The VPWR is the red wire (circuit 361) HO2S heater is the control circuit to the EEC (circuit 387 on right bank, circuit 388 on left bank) HO2S signal is the output to the EEC (circuit 74 on right bank, circuit 94 on left bank) SIG RTN is the low side and goes to the gray with red wire (circuit 359).

Bill - Thanks for that. But your info is backwards from what I think I found on the HO2S Sig & Rtn. I will check in the morning to see if I have that the wrong way 'round, but it looks like I do have from your drawing. I'll compare that to the harness I have and find out.

Also, where do you have the O2 sensor for your wideband? As said earlier, I can't get to a place for both banks until the back of the cab, and I'm not sure I even can then. So are you reading just one bank?

Last, below is a page from the '96 EVTM that I've marked up. Note that it says Ckt 359 (GY/R) is "12v with the brake pedal depressed". I figured that was an error, but do you know? It also feeds the ECT, IAT, and TPS sensors.

[85lebaront2]

Bill - Thanks for that. But your info is backwards from what I think I found on the HO2S Sig & Rtn. I will check in the morning to see if I have that the wrong way 'round, but it looks like I do have from your drawing. I'll compare that to the harness I have and find out.

Also, where do you have the O2 sensor for your wideband? As said earlier, I can't get to a place for both banks until the back of the cab, and I'm not sure I even can then. So are you reading just one bank?

Last, below is a page from the '96 EVTM that I've marked up. Note that it says Ckt 359 (GY/R) is "12v with the brake pedal depressed". I figured that was an error, but do you know? It also feeds the ECT, IAT, and TPS sensors.

Gary, 361 is power, 359 is signal return and is common to a lot of sensors.

My wideband O2 sensor is where the 1990 single O2 sensor went, just in front of the catalytic flange (when used).

I will send you the picture tomorrow.

[Gary Lewis]

Gary, 361 is power, 359 is signal return and is common to a lot of sensors.

My wideband O2 sensor is where the 1990 single O2 sensor went, just in front of the catalytic flange (when used).

I will send you the picture tomorrow.

Yes, 359 is return common to a lot, but I appear to have it swapped with the signal wire on both sensors. I'll check tomorrow.

As for the wideband, no need for the pic. I forgot that you have a wye-pipe and I don't. So you can get both banks up close. My banks don't merge until the back edge of the cab, and that is sure too far back for a good reading. So I think I'll have a bung put in whatever side is easiest.

[85lebaront2]

Yes, 359 is return common to a lot, but I appear to have it swapped with the signal wire on both sensors. I'll check tomorrow.

As for the wideband, no need for the pic. I forgot that you have a wye-pipe and I don't. So you can get both banks up close. My banks don't merge until the back edge of the cab, and that is sure too far back for a good reading. So I think I'll have a bung put in whatever side is easiest.

Mine is behind the transmission crossmember, and is in the hole the factory used on the E4OD trucks. You are correct in the use of a wye pipe, on the E4OD equipt trucks it is quite a piece.

[Gary Lewis]

Mine is behind the transmission crossmember, and is in the hole the factory used on the E4OD trucks. You are correct in the use of a wye pipe, on the E4OD equipt trucks it is quite a piece.

Thanks, Bill. Since I have the headers and duals I ran the cable for the wide-band O2 sensor down the back of the engine and tied it to the support for the fuel lines. That'll give me the ability to put it in the left bank's exhaust right behind #21.

As for what I did today, I finished up the wiring! As far as I know, it is D.O.N.E. And testing starts tomorrow. But for the most part I just need to test the power wiring and everything on top of the engine, like the injectors, TPS, IAC, ECT, etc. Plus I probably need to see that my wiring to the inertia switch and fuel pump relay is right. But I've already tested all the wiring that radiates from the PDB and/or connects to the ECU.

Why am I going to test all that? Because I thoroughly messed up yesterday's work and had to fix it today. So who knows what else is wonky?

Not only did I have the HO2S signal and return wires swapped in the connections going to the O2 sensor, I didn't have power to them. As it turned out I'd picked the wrong wire from C110, although how I did that I don't know as my wiring diagram, above, had the right wire.

Anyway, I got that fixed, the cables run back down to the O2 sensors and tested, the air cleaner and MAF sensor installed, the jumper made and installed from the EFI PDB to the battery isolator, and even the coil wire installed.

So what I have left to do is to test EVERYTHING, then set the timing, add the air intake plumbing, see if the fuel pump will run, and start it up.

Here's a view from the front:

And here's the view from the side:

[85lebaront2]

Thanks, Bill. Since I have the headers and duals I ran the cable for the wide-band O2 sensor down the back of the engine and tied it to the support for the fuel lines. That'll give me the ability to put it in the left bank's exhaust right behind #21.

As for what I did today, I finished up the wiring! As far as I know, it is D.O.N.E. And testing starts tomorrow. But for the most part I just need to test the power wiring and everything on top of the engine, like the injectors, TPS, IAC, ECT, etc. Plus I probably need to see that my wiring to the inertia switch and fuel pump relay is right. But I've already tested all the wiring that radiates from the PDB and/or connects to the ECU.

Why am I going to test all that? Because I thoroughly messed up yesterday's work and had to fix it today. So who knows what else is wonky?

Not only did I have the HO2S signal and return wires swapped in the connections going to the O2 sensor, I didn't have power to them. As it turned out I'd picked the wrong wire from C110, although how I did that I don't know as my wiring diagram, above, had the right wire.

Anyway, I got that fixed, the cables run back down to the O2 sensors and tested, the air cleaner and MAF sensor installed, the jumper made and installed from the EFI PDB to the battery isolator, and even the coil wire installed.

So what I have left to do is to test EVERYTHING, then set the timing, add the air intake plumbing, see if the fuel pump will run, and start it up.

Here's a view from the front:

And here's the view from the side:

Are you sure it is D.O.N.E.? I see a few places you could stuff something else into