New HPT Owner, New LS Swap Project (1966 C10)

[spectre1995]

Hey all,

I have a 1966 C10 with what I'm told is a Gen 3 LM7 (5.3L) out of a 2003-2005 Chevy Tahoe. Behind it is a 4L60E

I just found out today that the PCM I thought came with the engine is actually for a 2005 Chevy Express LQ4 (6.0L). This would explain why the engine *barely* runs at idle and why there's likely compatibility issues with the accelerator pedal and TAC module which came out of a junkyard 2003 Tahoe. I'm going to double check the block casting numbers tonight to see if the engine is a 5.3L or if its actually a 6.0.

My MPVI2 device is on order and should be here within a week or two. In the meantime I'm doing some research on what I need to get started, and have a few questions;

-First and foremost, can I reprogram the PCM to recognize the fact that the engine is a 5.3L out of a Tahoe and get it to recognize the TAC and accelerator for the Tahoe engine?
-Secondly, does a baseline tune exist to tell the PCM that the EVAP stuff as well as the second set of O2 sensors its looking for are no longer there?

I'll likely have lots more questions and will definitely be spending the next couple weeks researching til my brain hurts!

[TheMechanic]

What is the part number of the PCM?
Ideally you need to get a VIN of the combo you have. Then have the PCM likely a P59 programmed for that VIN. Then you can use HP to mod the factory programming. You will be better off as that range would likely give you the "fix" for throttle progression.

[2xLS1]

03-05 Tahoe is probably Flex Fuel. Most in that year range were. Get a part # off an injector and google it. 06-07 classic OS are not compatible with 03-05 ETC. Also describe the fuel rail. Vacc ref regulator on it with a return line to tank or dead head rail with no return. There are a few subtle differences in the 03-05 5.3s with flex and non flex. You can program the 06 box With an 03-05 OS with HP Tuners but it will cost 4 credits. Answering the questions will help pin down the actual year 5.3 and flex or non flex. The tune repository only contains stock tune files now. A tuner would have to provide a modified file if you are not able to modify a stock calibration for your needs. And there are quite a few besides evap and rear O2s for a swap.

[spectre1995]

PCM Part Numbers: (2005 - 2006 Chevrolet Express Van)
-Hardware #: 12589161
-Service #: 12589462

Block:
I got a bore scope behind the power steering bracket and found 4.8 / 5.3 cast into the block

Fuel Rail:
I found an intact label with the number 17204504. Traced to GM Part # 217-1542. Dead rail with no return line. I have a Corvette style pressure regulator in-line under the cab with a return line going straight back to the tank.

Fuel Injector:
Part # 25317620. I'm not sure if it matters but it has Multec 2 style plugs.

[2xLS1]

PCM is 05, injectors are standard 5.3 non flex 24 lb/hr, non return fuel rail indicates 04+, 03 would have a return fuel rail both flex and non flex. If it were me I would program your box with an 04 Silverado 5.3L OS. That would be compatible with any 03-05 ETC components you might be using. If you try and get a Tahoe file with your little experience you might accidentally end up with a flex fuel OS since so many of those vehicles were.

[spectre1995]

I'll look into that - thank you! So this computer will work and I won't have to go junkyard diving for a new one out of a Tahoe or something similar?

My MPVI should be here sometime next week, so I don't currently have access to the repository but as soon as it gets here I'll start taking a look.

This is quite exciting - before now I did all my tuning by sight and sound and with a screwdriver, tuning as I go (classic Volkswagens)

[blindsquirrel]

2005 Silverado 5.3 LM7 1550361377.hpt

[blindsquirrel]

2004 Silverado 5.3 LM7 2WD 18027469.hpt

Neither of these are the most current OS from TIS, so use these just for looking around.

[spectre1995]

Thank you, I'll check it out!

So will this flash require 4 credits, or just the 2 that I got with the MPVI?

Also, is there a way to buy a license to do certain year range PCM's, or is it always going to be vehicle specific?

[2xLS1]

You always have to have a license for the file that is in the pcm and the file you are writing to the pcm. Usually they are the same because you are writing a file that is based off what was read. In your case you will be writing a file not based off what was read, so 2 credits for the file in the pcm and 2 for the one you are writing. Be sure to Write Entire not Write Calibration. Another option would be to have someone with unlimited licenses change the box to the vehicle OS you want to use and then you would only license the new one in the box. Sometimes paying someone to get the correct vehicle/OS in the box can be cheaper than the cost of 2 credits. There are model YEAR licenses but they are both year and vehicle type specific. And if you don't have a MPVI yet how did you turn off the VATS to get it running at all.

[spectre1995]

I'll ask around my circle and see if anyone is able to reprogram it to the year / OS.

If I make changes to the tune later on, do I have to pay an additional 2 credits every time I write a new file to the PCM even if its the same year / model?

As for how I got it to run, honestly no idea. I just turned the key and it fired right up. Someone might have messed with the PCM before me, and since it came with the engine I bought (but the engine and PCM don't match), there's no way to tell any history on it.

[spectre1995]

My MPVI got here today and I was able to pull the OS off of the PCM - its number is 1272058 for a 6.0L and 4L80E. The VATS was already disabled, so that explains why I was able to get it started.

[spectre1995]

Grabbed a stock tune off of the repository, made a couple changes to it (deleted downstream O2 sensors) and flashed it onto the ECU. Idles and runs great now, and the throttle works perfectly. Thank you all for your help!

I'll likely have many more questions in the coming weeks, but for now my '66 runs way better than she did before I bought the MPVI