L31 into an '86 Regal Limited V8

[turboaudi]

what year is the truck you got the engine from i have several factory shop manuals for gm they will have the right pinout info somedata has many errors dave

 

[ATL Regal]

what year is the truck you got the engine from i have several factory shop manuals for gm they will have the right pinout info somedata has many errors dave

1997 GMC Sierra XC K1500

 

[ATL Regal]

I will be doing a L31 swap into a 63 Nova soon, so I thought I would subscribe. Basically, I got the engine and transmission for free and I thought it would be a reliable engine with plenty of power for my Nova. Anyway a couple of thoughts about this swap:
1) the fuel pressure needs to be about 60psi. I will be using a Ford truck external fuel pump as this is the easiest way to go. If you keep the tank at least 1/4 full, there shouldn't be an issue with starving the pump when cornering. Hopefully, the pump will not be too noisy. The pump I have was made by Carter I think (about $100 as I recall).
2) I haven't looked closely at the wiring to the PCM but I understand there were two different "black box" PCMs for these vehicles and that may be the discrepancy noted in the previous posts. I think the 96-97 was different than the 98 up. Note, that the Painless harness is based on the 97 computer 16229684. The last two years of the Express van (2001-2002 I think) used an entirely different computer, the 0411 computer which is also used with the LS1 engine. I intend to look at the Painless and Howell harnesses and just keep the same stuff on the stock harness. That's my thought at the moment. I have a complete set of manuals with wiring diagrams for the Suburban but someone borrowed them and I need to get them back.
3) I will be installing a Vintage Air system but the AC compressor will go in the truck location. I did buy a block to change the hose connections to the rear of the compressor.
4) The engines are designed for low end torque and have a very small cam. I think an LT4 cam work work well and may run on the stock computer tune. Since I am on a pretty tight budget, I intend to use the stock cam but I will use some 1.6 roller tip rockers that I hope will help a little. I think the engine will be a little over 300hp with full length headers and a better tune.

I'll follow along.

Mike

Thanks for chiming in!!!

I look forward to reading about your progress... and any input you have for me on my swap!

 

[ATL Regal]

I found this place: http://www.engineered.net

Just got off the phone talking to the guy about my swap.

He told me that I need to get it running and everything before I bring it to him and then he could program the computer.

He said that it should run without problems, but he was very vague about what I need to connect to the harness through the bulkhead in order to get the engine running.

He was basically trying to sell me on having him do or finish the swap, for $5000!!! (I shoulda told him to KILL HIMSELF)

I found another place: http://www.lt1swap.com/programming.htm

I have yet to talk to anyone from this site, but I'll call in a few. From what I read on the site, it looks like they do what I need to have done at a reasonable price. They have my engine listed and it says that they can program and delete VATS, EGR, MAP, MAF, etc.

*EDIT: No phone number is listed, I'ma just email them and direct them to this thread.

 

[nova_rookie]

Here is a pinout diagram for a 1997 I found on line:

http://www.justanswer.com/uploads/carfi ... 6_sub5.pdf

This is the stuff that is necessary based on some aftermarket harnesses:

http://www.hotrodlane.cc/harnessinstruc ... 252011.pdf

http://www.jegs.com/InstallationInstruc ... -60212.pdf

I am going to try to modify the stock harness and keep the stuff found in the aftermarket harnesses.

The cheapest aftermarket harness is from Howell (around $600). I think I will get the PCM reflashed (remove VATS, rear 02 sensors, etc.) from http://www.pcmforless.com/

Mike

 

[ATL Regal]

Here is a pinout diagram for a 1997 I found on line:

http://www.justanswer.com/uploads/carfi ... 6_sub5.pdf

This is the stuff that is necessary based on some aftermarket harnesses:

http://www.hotrodlane.cc/harnessinstruc ... 252011.pdf

http://www.jegs.com/InstallationInstruc ... -60212.pdf

I am going to try to modify the stock harness and keep the stuff found in the aftermarket harnesses.

The cheapest aftermarket harness is from Howell (around $600). I think I will get the PCM reflashed (remove VATS, rear 02 sensors, etc.) from http://www.pcmforless.com/

Mike

Mike, I'm not sure what I'm supposed to take from that information.

I looked at it all and I see where the www.hotrodlane.cc has a very simplified version of my harness, but it's modified. Are you suggesting that I strip my harness down like that? If so, why? Is it that I won't need a lot of the wiring that's in the stock harness?

I want to use all my peripherals, I mocked it up while I had the engine all the way in and I'll be using pretty much every plug on that harness.

I basically need to know which pins to take out of the PCM connectors in order to remove the rear O2 sensors, and whatever else I need to make it run properly.

I've done a little reading and I realize that I have both MAP and MAF sensors on this engine and from what I gather I'll need both in working order to get the most out of the engine. I also read a little on the EGR valve, although I still don't fully understand it, I think I need to keep it as well.

So that leaves me with VATS, which I'm not sure I have because the truck was a '97. How do I verify if I have VATS and which pins I need to remove for it?

Also, about the O2 sensors, the bungs for both the before and after O2 sensors were on the truck's catalytic converter mid-pipes (between the manifolds and muffler) like this:

I still have this hanging in my garage with the O2 sensors still in the bungs, but I'm sure it won't fit this application. And the headers I bought don't have any bungs for 02 sensors, nor does the true dual pipes that were flanged up to the 307's exhaust manifolds.

So, what do I need to do about the 02 sensors?

 

[nova_rookie]

ATL Regal,

You stated,

"I basically need to know which pins to take out of the PCM connectors in order to remove the rear O2 sensors, and whatever else I need to make it run properly."

I see the aftermarket harness as the minimum set of connections "to make it run properly". I did not personally take off the original harness so it gives me an idea where all the connections are and what they do. If there is a wire/connection in the orginal harness not used in an aftermarket harness then I will contemplate whether I really need it. For instance, I don't suspect I will need the wire for the VSS input to the anti-lock brakes.

As for 02 bungs, you will have to have them welded-in probably to your headers. I think you are supposed to avoid a low point so moisture does not accumulate at the sensor. You should do some google searches to see if you can get some in-sight from others.

You computer definitely has VATS, it will need to be programmed out when the computer is reflashed. There are a number of things which will have to changed in the computer tune, for instance the tire diameter and rear gear ratio will need to be given to the tuner so the VSS gives the proper signal.

I will be pulling the harness out of storage in the next couple of days so I will be doing some more research.

Mike

 

[Doober]

You can send the PCM out to have it flashed, and tuned for any changes you may make (headers, etc.).
www.fullsizechevy.com

Reflash may be up to $300 or so, and the vehicle isn't required to do this... you just ship the PCM out and they ship it back.

Unless you can find a standard rotation pump that will work on a Vortec block and intake, you'll have to use a serpentine setup, the factory Vortec coolant setup uses a special pump, unlike a standard/reverse rotation pump. An aluminum bracket setup from a 4.3 S-Series or TBI full size truck will work, but the compressor will be on the passenger side and you'll need a different compressor (why GM put the compressor on the driver's side is beyond me, more work to route a/c hoses than wiring for the alternator).

 

[nova_rookie]

ATL Regal,

I may have been wrong about the VATS. I did read somewhere that the computer VATS started in 1998.

As for the 02 sensors, I think you want Bank 1, Sensor 1 (drivers side) and Bank 2, Sensor 1 (pass side). Bank 1 Sensor 2 and Bank 2 Sensor 2 will be deleted (these are the rear 02 sensors). This is based on other sites, make sure the wire colors make sense.

Here is some useful wiring information:
http://lt1swap.com/96-99_vortec_harness.htm

The owner of the site, Brendan Patten, charges $75.00 to reflash the computer.

I pulled out the harness today and did some cursory routing. The harness is a big mess and it will be a harder job that I thought . I will tease out the air conditioning wires and the delete the canister purge. I'll probably delete the EGR valve as well, here is an EGR delete plate: http://www.ebay.com/itm/CHEVY-S-10-S10- ... 3a7c82735a

I will be using the truck serpentine accessories.

I' ll look at this a little closer tomorrow.

Mike

 

[ATL Regal]

What wires I need to go in the firewall?

Keyed (switched) ignition
Constant power
Tach
Earl pressure
Water temp
VSS (from 4L60E)