LT 1 wiring harness

[nailed]

I picked up a old caprice police car at the auction for my 60. Good running 94 LT1 for $125.00 no BS. So I called painless and they want 951.00 for the harness to adapt into my 60. OUCH I started looking around on the net and have found better priced ones. My consern is quality service ect. Does anyone have a leed on a good company or a way I can use the factory harness and provide the right signals to the ECU? I am ready to spend some time and money to get this running but there must be a better way than blowing the budget before I get started. Any help from you guys would be appreacated. Thanks

 

[mwdubs]

You dont need those guys, you need this guy, or at least his web address. LT1 Swap He will do it for you at 1/3 the price, or if your comfortable with cutting and splicing, you can just read the instructions on the site. He basically tells you everything you need to know. Between my father and I we've done 5 or 6 LT1/LS1 swaps over the past few years, mainly hot rods and have used Fuel Injection Specialties ( In Texas ). They typically get around 5-600 for a harness. I'm planing a 5.3L chevy for my 60 right now, I've contacted this guy (lt1swap) and he is willing to help me through it. Hope this helps.

 

[nailed]

I did check out fuel injection specialties, must have been under a rock for a few years because I have never heard of them. Yhe LT1 site sounds good.

Thanks for the info.

I'm not sure why the thumbs down on the post. Its never a problem, just a opertunity.

 

[rover67]

may also want to call these folks up: Wait4Me Performance I'm not exactly sure if they do LT1 wiring, but he may. I used FIS and got pretty frustrated for a few reasons, ended up using wait 4 me this time. I have heard good things from folks that have used them in the past for LS1 swaps..

 

[MANUCHAO]

If you know of any "local" outfit that can do your harness then you should use them....
Nothing like being able to taking in the problem to the ones that did the work and have it fixed on the spot.

I used FIS as well and Im still dealing with a lot of their mistakes/screw ups......... it has been expensive and frustrating to say the least..

Post a thread once you start your project ...with lots of pics too....!!!

Good luck !!

 

[lehiguy]

I did a TBI installation from scratch using a wrecking yard harness. It wasn't too bad, and I'm no electrical genius. If you can get hold of a schematic diagram, you should be able to use the original harness. I don't know about the LT1s, but the TBI trucks had very little extra junk on the harness. All of the in-the-cab stuff is separate.

 

[chicago]

If you know of any "local" outfit that can do your harness then you should use them....
Nothing like being able to taking in the problem to the ones that did the work and have it fixed on the spot.

I used FIS as well and Im still dealing with a lot of their mistakes/screw ups......... it has been expensive and frustrating to say the least..

Post a thread once you start your project ...with lots of pics too....!!!

Good luck !!

Forgive the hijack, but FIS did you wrong!?
That is the first that Ive heard of that. What problems have you had with the system that they did?
Im curious as Im considering them for my harness. I got a lead on another company that was a bit cheaper and has been used by a respected member of the LC community for some time for numerous conversions.

Again, sorry for hijack...PM me for your response.

Chicago

 

[redcorn]

Speartech Fuel Injection Systems

$450.00 to rework the factory harness and maybe $150 for ECM reflash.

Phuck Painless

 

[rover67]

I will not go back to FIS after my struggles with them either. At first I thought they were great, but as I have learned more I discovered they were not all they were cracked up to be.

The harness they did for me is now being redone as we speak.

 

[DirtyLittleSecret]

LT1 Wiring

They were great, and would utilize them again in a heartbeat. Flashed my ECU, and tagged all the wires for me. An awesome deal, and the customer service proved them worthy of my $.

 

[Tinker]

Money & time are interchangeable. Painless stuff works out of the box, period. And if you have any questions they are ready to answer them.

Why did you guys "have" to have your ECUs reflashed? Mine is stock, but I'm using the donor tranny as well.

 

[chicago]

Money & time are interchangeable. Painless stuff works out of the box, period. And if you have any questions they are ready to answer them.

Why did you guys "have" to have your ECUs reflashed? Mine is stock, but I'm using the donor tranny as well.

Im of the impression that you had to, (reflash the ECU)?
Dont they need to reprogam the ECU to match your running gear and accessories.
The way it was explained to me, they will essentially down load gears, tire size, tranny etc into the ECU to better fit the entire rig. Seems to make sense, but what do I know.
If theres an easier way, please post it up. The more info the better.
Im learning from others experiences on this.
Are you throwing any codes with the set up you have?
So you like the painless system? For what reason? Is it a plug and play type deal? Do they custom build the harness? Was there any additional splicing that YOU needed to do? Have you encountered any problems? Did you look at any other compaines before deciding on the Painless system?

Thanks. Im really interested here!
Thanks for starting this post.

Chicago

 

[Dynosoar]

I don't think OBD I computers need to be reflashed. It is only the OBD II computers that do. LT-1's come in both flavors (OBD I and OBD II) so it depends on the year. Pre 1994 is all OBD I. 1995 is a weird OBD 1.5, and 1996 on is OBD II. I think OBD I is an easier system to adapt in a conversion.


Dynosoar

 

[rover67]

the computers just need the non used functions disabled. that's all.

 

[Tinker]

Chi-

I'm running a '98 5.7 Vortec with matching 4L60E, 4.11s, & 10.50x33 BFG MTRs. Never had to get the ECU reflashed to sync things up 'cause it runs great like it is. Goat-like 1st gear + lockup 4th OD gives me 75mph @ 2,200 rpm. Got 17 mpg on day going up I-70 to Silverthorne & back plus some around town putting (I've gotten over hot-rodding it like I did when it was 1st together: saw 95 mph once & the speedo reads about 10% low).

Not throwing any codes, but the OBDII setup is great if you have a code reader (which I do). You can diagnose problems in a hurry.

I like the Painless system 'cause it's plug-n-play with clear directions. They sell a harness specifically for your application. I had my swap done 'cause it's way out of my league with the ECU & slushbox & I don't have a lot of spare time. The shop that did the conversion insisted on the Painless harness & they certainly could have run the bill up (more!) by wiring it themselves. When I ran into problems afterwards & didn't want to mess with the shop I studied the directions & called Painless with questions. They were extremely helpful. I can't imagine splicing the Toyota & Vortec harnesses together, & I've trouble-shot my share of electricals when I was in transportation R&D.


BTW get the Downey swap manual & study it 1st: Part # 00MAN TBI/TPI Manual $25.00 bottom right corner of the page Downey Off-Road

 

[mwdubs]

one thing that gets taken out of the computer is the VATS, vehicle anti-theft system and the aft-cat o2 sensors if not needed in your state (no need for them here in nc) just my .02

 

[Elbert]

I think on most of the OBD I stuff you need to have a chip "burned" to capture your modifications, since I don't believe there is a way to program or flash the ECM. On the newer OBD II stuff you can buy programs that let you interface with the PCM (what used to be called the ECM). There are rather expensive and require some expertise to use, or you can have one of the shops that specalize in programming to program your PCM for you, or some are still in the business of burning chips.

If you could swap in a complete engine / transmission combination you potentially might not have to reprprogram the engine if you run all the emissions controls, and catalytic converters...etc.

I've read where some people don't like the LT1 for offroad due to the location of the distributor, I think its still called the distributor on that engine...anyway its down by the water pump. I would make sure to talk with the guys who work with the LT1 engines. The vortec 5.7 is somewhat similar, the newer 4.8 and 5.3 & 6.0 engines are their own family of engines.

Make sure you understand what type of radiator you'll need, as I think the LT1 engines have reverse flow "coolant system", which requires a special modification to the radiator?

 

[ntsqd]

The "reverse flow" coolant system of the LT1 pushes the cool coolant thru the heads first, then thru the block. Older SBC's and most other U.S. V8's have the cold water pushed thru the block first. Other than potentially needing the hot and cold ports in different locations, a normal radiator should work.

The only possible unique thing that I can think of would be if there are air bubble bleed hoses that need to be connected to the radiator.

 

[chicago]

Chi-

I'm running a '98 5.7 Vortec with matching 4L60E, 4.11s, & 10.50x33 BFG MTRs. Never had to get the ECU reflashed to sync things up 'cause it runs great like it is. Goat-like 1st gear + lockup 4th OD gives me 75mph @ 2,200 rpm. Got 17 mpg on day going up I-70 to Silverthorne & back plus some around town putting (I've gotten over hot-rodding it like I did when it was 1st together: saw 95 mph once & the speedo reads about 10% low).

Not throwing any codes, but the OBDII setup is great if you have a code reader (which I do). You can diagnose problems in a hurry.

I like the Painless system 'cause it's plug-n-play with clear directions. They sell a harness specifically for your application. I had my swap done 'cause it's way out of my league with the ECU & slushbox & I don't have a lot of spare time. The shop that did the conversion insisted on the Painless harness & they certainly could have run the bill up (more!) by wiring it themselves. When I ran into problems afterwards & didn't want to mess with the shop I studied the directions & called Painless with questions. They were extremely helpful. I can't imagine splicing the Toyota & Vortec harnesses together, & I've trouble-shot my share of electricals when I was in transportation R&D.


BTW get the Downey swap manual & study it 1st: Part # 00MAN TBI/TPI Manual $25.00 bottom right corner of the page Downey Off-Road

Thats good info, thanks for the response!
Ill check into that manual!

I started my own thread on this swap, so Im done hijacking this one.
I apololgize.

Chicago

 

[Elbert]

don't recall where I read it, but yeah the readiator is "normal"...but does require some type of modification to facilitate a LT1 engine..