rll2

iTrader: (8)

Apparently I'm and Idiot
Because the 97 LT1 to LS conversion was supposed to be so easy that anyone could do it
I started this conversion over 10 years ago
With that being said, I don't work on it everyday
Not even close
I travel for my job and can be gone for weeks at a time
I've spent thousands of dollars paying different people to get the car going, and always ends up the same
I get the car back and I have to either finish or redone the work that I payed for
I will say that the last guy got it running, but it was far from a finished driver
The gauges didn't work, I had most, if not all, the idiot lights on
I had bought a harness years ago that was supposed to be a Speartech conversion harness, but wasn't
I know this because I took it to Speartech to get some things repaired that weren't working correctly
Going to need help getting everything rewired
I guess my question is
Here 10 years later
How's the best way to do this conversion now, which vendor for harness work/parts
Would I be better off to do a stand alone harness, and if so, how do I get my factory gauges to work with the new harness

Thanks,
Rob

93Z2871805

iTrader: (5)

Taking it back to 10 years ago, the best way would be to rewire a 99-02 harness to run an 0411 PCM and use your factory gauges. That's how I did it originally with help from a few forum members and resources:

https://ls1tech.com/forums/conversio...o-lt1-car.html

https://ls1tech.com/forums/conversio...on-sticky.html

https://ls1tech.com/forums/conversio...-diagrams.html

However, if I were to take on this swap in today's day, I would look to retain the factory LT1 computer as a driver for the gauges only and run a Holley ECU as a standalone:

https://ls1tech.com/forums/pcm-diagn...m-install.html

SAPPER

iTrader: (10)

It's not nearly as hard now as it was 10+ years ago. There are many resources and options out there and several different ways to accomplish this. First, as for any wiring swaps, contact Bill at BPAutomotive. He is the leader in harnesses and a wiring master. The mechanical side isn't very hard at all. If the car is an A4, the swap is only a flexplate and bushing. If it's a M6, it's a little more involved in retaining the LTx T56 but not bad. Sometimes it's better to swap over to a LSx T56.

rll2

iTrader: (8)

With the fact that I already have a 99 harness (that's been converted to use with the LT1 car) and the LS1 computer
Should I go back to a LT1 harness and computer, if I want to use the terminator X engine management system

Thanks,
Rob

93Z2871805

iTrader: (5)

That would appear to be the easiest route if the Holley would be controlling everything, the factory harness and ECU would just be along for the ride (sending units and driving gauges). Albeit, I'm not aware of someone that tunes LT1 ECUs to function as a monitor only (without a TPS, cam position, and crank position) and still produce an OBDII output, so I can't comment from that side.

the_merv

iTrader: (88)

Considering every car that was an LT Fbody that I had built a DIRECT PLUG IN harness for when they did an LS Swap, was running and driving with no issue when tuned, I find it extremely hard to grasp how you can have that many people who are potato working on that car you have. As long as these cars have been out and what knowledge people "claim" to have, stop using people who don't know what they are doing.

These cars are mid 90's Fbodies, with a factory EFI System, Electronic Gauges that work with the FACTORY sending units on the LS Engine, wired to install a GM PCM to run the whole car.

Why deviate from that? IT WORKS. I've done over 2 dozen. I must be the Jedi master of these cars apparently over these companies who claim their business is wiring. I need to patent my harness design for this.

Stop using incompentent people.

93Z2871805

iTrader: (5)

Ladies and gentlemen, he's back.

OP, taking it back to 10 years ago, if you're looking at doing factory gauges, 0411, and an LS Swap in a LT car, Merv is the one you want to talk to. He's the one that built my harness, and I literally only had to connect switched 12v to the OBDII port, everything bolted in like stock.

Standing by my previous statement though, if I were doing the swap today, I would be considering a Holley with an OEM ECM along for the ride, but it might take some development in getting the programming to work. Bottom line, for ease of install I would go 0411 on a converted harness, for capabilities (depending on what I want the car to do) I would go Holley.

the_merv

iTrader: (88)

I lurk around here from time to time researching stuff, haven't really chimed in much because I put my hands in whatever I'm working on and get it done after I find what I need.

With the above posts mentioning other ways to run stuff, in a setup where you are installing a true stand-alone harness/system and needed it all to go, with what is out nowadays I would recommend that. All day. Self learning systems are easy to use and have come a long ways in the last 10 years. Worked with a few.

This case here, the mid 90's Fbody, as well as pretty much everything GM late 80's up, the vehicle from the factory is setup EFI and capable to have a harness literally built that directly plugs in to run the Engine & Transmission using the LS PCM, and run Factory Gauges. Why complicate that, it's a simple install. Done it with Fbodies, S10's, Full Size Trucks, did a couple C4 Corvettes...yea I'll stand behind using the factory stuff in this case. Maybe I figured that out because I'm smarter than the average potato.

Install Drivetrain correct, Install 58psi capable Fuel Pump and set the fuel system up correct, wire it all in correct, tune it correct (competent tuner needed here), drive and enjoy.

Constant Battery Fused 12v....