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LTX and LSXPutting LT1s, LS1s, and their variants into Third Gens is becoming more popular. This board is for those who are doing and have done the swaps so they can discuss all of their technical aspects including repairs, swap info, and performance upgrades.
As far as why I use ES2000 heat shrink in some locations and SCT heat shrink in other locations, it's because I have both in different sizes. They both have similar specs, but I have noticed that the SCT has a longer "workable" time during cool down so it's been more user friendly with larger bundles.
Here is link to Raychem catalog of heat shrinks, Document 9-1773447-9 It's overwhelming how many choices there are. I just narrowed the field to those with better ratings of flammability and chemical resistance.
Mocked up and starting to take shape. Gosh, I forgot how thick the bundle is.
In retrospect it would have been nice to concentric wind that sucker but this is my first build and I'm just not that advanced yet. I need something equipped with "change my mind" features you know!
Ignore all the zip ties, those will come off later. Bulkhead is complete. Now I need to do a few things to make it possible for the harness to interface to things in the interior of the car.
Zip ties are "de rigueur" when building a cable harness. If a bundle requires a half dozen when complete, (in the absence of wiring loom), a hundred have been applied and sacrificed in it's creation.
Looking good Mr Q.
You DO have flush cutters I would suppose. The little razor blades left behind after trimming with conventional side cutters will result in scars that I carry on my forearms. They're nasty business.
Last edited by skinny z; Apr 25, 2023 at 09:22 PM.
By the way, I tried to make a twisted pair for CAN wires but when I took it out of the drill the wires partially unwound themselves and pretty much lost half the winds per inch I had put in it. It's still a twisted pair, just not as tight as I wanted. How do you keep it from unwinding itself?
By the way, I tried to make a twisted pair for CAN wires but when I took it out of the drill the wires partially unwound themselves and pretty much lost half the winds per inch I had put in it. It's still a twisted pair, just not as tight as I wanted. How do you keep it from unwinding itself?
The other question I've got is I notice the wires in the Holley harness lay pretty straight and don't want to coil up, whereas my wires want to coil up. I'm guessing that's from the way it was packaged and there's not much I can do about it? My wire spools are teeny tiny (100 foot) and the wires are wound on a small diameter. I'm guessing in the factory the spools are very large diameter and the wires don't get near the coil set into them and naturally lay flatter. Is there any tricks to making the wires behave better besides hanging them like dried meat for 6 months?
In all seriousness, yes more zip ties.
But I've found some wire takes to twisting better than others. In the problematic cases, I'll create the twist and keep the free end anchored in a vise, pliers, a brick or something to keep it from unravelling. The drill end is captured with a cable tie and then similarly anchored until it's installation. Most of my "custom made" twisted pair, which admittedly is few and far between as it's a non-automotive application and we use OEM pairs, the cable spec isn't as intense as you and vorteciroc have demonstrated. Often the entire length is covered in heat shrink. That obviously keeps the twist. Some of this automotive wire is difficult to deal with.
The other question I've got is I notice the wires in the Holley harness lay pretty straight and don't want to coil up, whereas my wires want to coil up. I'm guessing that's from the way it was packaged and there's not much I can do about it? My wire spools are teeny tiny (100 foot) and the wires are wound on a small diameter. I'm guessing in the factory the spools are very large diameter and the wires don't get near the coil set into them and naturally lay flatter. Is there any tricks to making the wires behave better besides hanging them like dried meat for 6 months?
Build yourself a DIY mandrel. I was going to say this is difficult to describe however, if memory serves, didn't you build something to straighten out your steel tubing? A similarly scaled version can be built to draw your small diameter wire gauge through. I've done this with screws mounted on a piece of plywood.
In a pinch, I've taken said wire, and repeatedly drawn it between my fingers (leather gloves are useful here). The heat created from the friction and the repeated draw through the mandrel like fingertips, relaxes the wire and makes it easier to work with.
Simple suggestions from a simple tradesman.
By the way, I tried to make a twisted pair for CAN wires but when I took it out of the drill the wires partially unwound themselves and pretty much lost half the winds per inch I had put in it. It's still a twisted pair, just not as tight as I wanted. How do you keep it from unwinding itself?
Zip ties work, and I have also used heat shrink and electrical tape to help keep the wiring tight.
I usually have to pass the wire through a firewall when wiring kill switches at the shop so the tighter the wind, the easier it is to deal with.
Mocked up and starting to take shape. Gosh, I forgot how thick the bundle is.
In retrospect it would have been nice to concentric wind that sucker but this is my first build and I'm just not that advanced yet. I need something equipped with "change my mind" features you know!
Ignore all the zip ties, those will come off later. Bulkhead is complete. Now I need to do a few things to make it possible for the harness to interface to things in the interior of the car.
By the way, I tried to make a twisted pair for CAN wires but when I took it out of the drill the wires partially unwound themselves and pretty much lost half the winds per inch I had put in it. It's still a twisted pair, just not as tight as I wanted. How do you keep it from unwinding itself?
One option that I tell people that do not want to deal with Twisting Wires...
You can purchase a Length of that Shielded 3-Conductor Wire from Holley (CMP and CKP Sensor Wire) and use it as a twisted pair for Can-Bus as well.
Oh, crap!! I just came to realize much of the Holley wire size documentation in their EFI manuals is wrong. I used that documentation as a starting point for my harness and they listed much of the harness as 22 AWG when it is really 20 AWG. I thought it was suspicious that I kept finding 20 AWG wires every time I measured out something!
I walked through the documentation of my build and I used 22 AWG for all the sensor signal wires, custom inputs, IAC sensor, and the ignition coil outputs.
* Pretty sure 22 AWG is fine for sensors signals and custom inputs.
* IAC likely needs an upgrade to 20 AWG.
* And guessing coils need upgrade to 20 AWG?
This is what I get for not using the flying lead harness, but honestly I hate the kaleidoscope of colors. Very much prefer my own color scheme because I can look at a wire and know exactly what is its function without even needing to reference a schematic.
* Pretty sure 22 AWG is fine for sensors signals and custom inputs. YES
* IAC likely needs an upgrade to 20 AWG. YES
* And guessing coils need upgrade to 20 AWG? Signal Wires or Power Wires?
This is what I get for not using the flying lead harness, but honestly I hate the kaleidoscope of colors. Very much prefer my own color scheme because I can look at a wire and know exactly what is its function without even needing to reference a schematic.
My Answers are in RED.
As far as Wire Color goes...
That's usually going to go unseen for the most part, with Braided-Sleeving or Heat-Shrink Sleeving anyway.
Some of us do not even bother with any Colored Wires at all:
I'm just going to capture this so I don't forget. My car instantly died again this morning, same as in the spring, and I eventually got it to run and put it back in the garage. ECM would not communicate with laptop and could not get a datalog, same as a couple months ago. My battery had died recently and I just put a fresh battery in the car about a week ago and had driven several times since then.
Talked to Holley tech and walked through the history of this problem and it seems maybe the common thread is I had a discharged battery before each of these events. They say that if the ECM is powered up with low voltage that it could possibly corrupt a file, and recommend reloading firmware and tune if that happens. That's basically what I did last time (by happen-stance) when upgrading from V4 to V6 firmware. I'll reload everything again now and sit back and watch what happens, I guess.
And yes, I bought a different battery tender. The one I had was apparently overcharging the battery and completely dried out a cell. This new one is supposed to be smarter about float charge.
I'm getting a little tired of this stuff because it's affecting the way I drive... or more like the way I'm not driving the car. Very little seat time this year because it's not worth the hassle.
Yes sir. Every level of new tech we add to our cars becomes another area prone to failure or malfunction.
Something as simple as a Dakota digital temp controller caused a lot of grief because when it went sideways, engine temps went through the roof. Looking back over those episodes and I'm thinking that overheating had a hand in the demise of the shortblock.
While my Camaro isn't nearly as complex as your Firebird there's something to be said about a 1-wire, 1-fuel line hot rod. I WAS there at one time but have steadily increased the number of wires and fuel lines for little more than modernization it seems.
Good luck with your troubleshooting.
Why Holley doesn't focus on and can't just fix these types of basic problems after all these years is incredible... This is has been a known issue for many years and one of the reasons i just gave up on them... lots of nice things with holley efi but mission reliability isn't one of them unfortunately
And yes, I bought a different battery tender. The one I had was apparently overcharging the battery and completely dried out a cell. This new one is supposed to be smarter about float charge.
What did you get? I'm in the market for another replacement myself.
Or combine the two so regulator and a low/high shut off that is within the regulator parameters.
Holly tends to be very sensitive to voltage issues, I am surprised the they don't have a low voltage cut off built into the ecu. It really wouldn't add too much to their product cost to have a better power circuit. Even one with a small li ion back up battery to keep it from corrupting the firmware if it looses power. Or simply have a hot/cold firmware. If primary firmware fails to boot, flash the cold firmware into the hot and boot, if it still fails boot in the cold and throw a code.
Last edited by Aviator857; Jul 10, 2023 at 03:01 PM.
What did you get? I'm in the market for another replacement myself.
I didn't put any thought into it, Skinny. Just grabbed whatever was on the shelf at my local Interstate battery store when exchanging the battery. It at least turns itself off, whereas my last one trickle charged constantly no matter what.
Reloaded V6 220 software and it went really quick (I don't ever remember it being that quick). Car started, but it started before too. But now the sync with laptop acts a little funny, claims it worked but doesn't show me progress bars. And the virtual gauges on laptop don't display anything. Basically I'm getting no live updates from ECM to laptop.
And to top that off, my old trusty Windows 7 Dell laptop is gradually breaking down. The lid hinge broke a couple years ago and now today the display stopped working. So I had to hook up a monitor to the computer to see what I was doing. Computer is probably 15 years old. I wonder if my computer is just a tad out of date for the latest V6 software integration to go smooth? It's not like I have a newer ECM though, it's the older HP built on the Terminator platform so it's kind of the same era as my computer.
I guess I could plug in my Dominator and lay it on the floor for now as a test but I've got to make a stand-alone programming harness for it first because I have no idea what tune is on it and if it will short out or what if hooked directly to my car.
I figure you've done this a thousand times. Do you have recommendation for an affordable bench power supply I can use to flash my Dominator ECU? And can you make a compatible harness that I can plug into the ECU, with a convenient on/off switch so I can cycle the switched B+?
I am rather clueless when it comes to power supplies. I don't know if I'm getting into $20 or $2000? I could connect it to car battery instead if I'm being unrealistic.
By the way, I tried to make a twisted pair for CAN wires but when I took it out of the drill the wires partially unwound themselves and pretty much lost half the winds per inch I had put in it. It's still a twisted pair, just not as tight as I wanted. How do you keep it from unwinding itself?
Twisted wires can be some work. I add 15% length to the estimated run. Tape the first end and hold it in a vice. Keep the wires tight and tape the other. Load the second end in a drill keeping light tension on the wires. Pinch 16-18" away from the drill and slowly spin until the twist is roughly as tight as you want it. Stop the drill and pull you fingers back across the twist. This slightly stretches the wires and bends the copper core into little windings. You can test this be releasing it from the drill chuck. Some unwinding is expected but it should stay tightly twisted. If it mostly unwinds, then you didnt pull hard enough across the twist
Repeat this every 16-18" of the run. Cut off the sections that were in the vice/drill as they will be damaged
The main thing to remember is to keep tension on the entire length with the drill. Any slack will allow a loop to form which will become a kink and break the wire ruining the entire run
The alternative is to buy holley's expensive shielded cable
The other question I've got is I notice the wires in the Holley harness lay pretty straight and don't want to coil up, whereas my wires want to coil up. I'm guessing that's from the way it was packaged and there's not much I can do about it? My wire spools are teeny tiny (100 foot) and the wires are wound on a small diameter. I'm guessing in the factory the spools are very large diameter and the wires don't get near the coil set into them and naturally lay flatter. Is there any tricks to making the wires behave better besides hanging them like dried meat for 6 months?
It's all in wire management while you build the harness. Zip ties/tape are fine for a one off and/or table build. Most of mine were done on a large wall mounted board, routing through nails and pegs. Near the termination point I had to thin nails close together to lightly pinch the wire(s). Some masking tape to keep the wire bundle together was all it took. The main harness trunks didn't have any excess length to try to coil back up
Building a wire rack will also help with the coiling up. Off a rack, a pulled wire will come off strait (assuming it was spun on strait). If the spool is laid flat on the floor and a wire pulled, it will spin causing a twist along the wire's length. It's not a big deal for a couple feet, but 15-20' it gets noticeable, especially along wires with a stripe
Some of us do not even bother with any Colored Wires at all:
My first couple harnesses were all black. They were exceedingly difficult to troubleshoot from afar and time consuming to manufacture. I very quickly bit the bullet and ordered all the standard colors for LS. If it works for you, keep on keeping on
Why Holley doesn't focus on and can't just fix these types of basic problems after all these years is incredible... This is has been a known issue for many years and one of the reasons i just gave up on them... lots of nice things with holley efi but mission reliability isn't one of them unfortunately
Try getting them to warranty an ECU. I think the DMV has a better turn around rate than holley
Pfffftttt!
And you guys trust Drive By Wire on Holley EFI!
After chasing DBW issues on GM stuff, none of my builds get DBW ever. I like the idea behind the system and how well it works on production vehicles, but in swaps... far too problematic and difficult to address
My first couple harnesses were all black. They were exceedingly difficult to troubleshoot from afar and time consuming to manufacture. I very quickly bit the bullet and ordered all the standard colors for LS. If it works for you, keep on keeping on
My approach as well. Not only in troubleshooting but for modifications also. Should any given component need to be upgraded or relocated, it's very convenient to be able the go into the loom and any given point and retrieve the circuit in question.
100% necessary. Obviously not. But certainly a time saver.
Building a wire rack will also help with the coiling up. Off a rack, a pulled wire will come off strait (assuming it was spun on strait). If the spool is laid flat on the floor and a wire pulled, it will spin causing a twist along the wire's length. It's not a big deal for a couple feet, but 15-20' it gets noticeable, especially along wires with a stripe
In addition to pulling the wire from the roll as it was spooled on, I've found that drawing the wire between the fingers while giving it a little stretch will tame some the curl that's seems inevitable.
it's also very dependant on the wire in use.
While not specific for automotive needs, given the flame spread and toxicity requirements, I'm a fan of using TEW machine wire. Very finely stranded, flexible and easily managed. The insulation is rubber based rather than nylon so it stands up well to life under the hood as it's also oil and gas resistant and carries a 105°C temperature rating.
Last edited by skinny z; Jul 16, 2023 at 12:07 PM.
I figure you've done this a thousand times. Do you have recommendation for an affordable bench power supply I can use to flash my Dominator ECU? And can you make a compatible harness that I can plug into the ECU, with a convenient on/off switch so I can cycle the switched B+?
I am rather clueless when it comes to power supplies. I don't know if I'm getting into $20 or $2000? I could connect it to car battery instead if I'm being unrealistic.
Affordable... not really.
Sorry.
Price starts to clime quite high with the Amperages needed for the PCM.
Used my homemade pass-thru harness to flash firmware and a tune on a Dominator ECU. This was just a bench test, but I'll take the win. It's better than FOOOOP! *Smoke billow*
Now that I think about it, that was kind of ballsy (different word for stupid) to put a new Dominator ECU on the line. Maybe I should have tested with the old HP ECU first!
We have the 3 different types of GT150 Sealed Connectors...
-Classic uses the Metri-Pack Seals: Delphi Tool #12085270/ Sargent #3186
-Regular uses the Slightly Larger GT150 Seals, some will fit the Delphi Tool #12085270/ Sargent #3186... Others will need Sargent #1026.
-3.5 Cent. uses Slightly Smaller GT150 Seals and uses the Sargent #1026.
It's the result of frustration. I'm definitely learning as I go....
I have several Delphi ratcheting crimp tools and became frustrated with how poorly they work in some cases. Too many problems with wings not fitting in the die, under crimp, over crimp, terminal rolling, bending, and loose cable seals. I had to develop my own crimp maps to try to compensate, sometimes doing multiple crimps (full and partial) depending on terminal part number and wire size. It all got to be too much of a PIA trying to get the results I want.
I ended up having a talk with an application engineer at APTIV and learned that the tools are field service tools with different crimp dies than what is used in production. In other words, they're kind of generic, not super specific to what they are advertised to do.
The Rennsteig tools have production quality dies. Place the terminal into the die and it actually fits like it should. It has wires stops to locate the wire into position. It crimps everything in one step. And it measures out perfect when you're done. No practice needed. My frustration is over. Downside is they are rather expensive.
I'm going to keep the Delphi tools for doing my odd-ball work such as making wire splices and such.
The Rennsteig tools have production quality dies.
.
Is there a specific terminal required? By that I mean, with my Panduit fork and ring style crimper (the traditional red, blue and yellow closed barrel crimps) the dies are so specific that the insulating material, be it nylon or vinyl, is specified.
I find that with open barrel crimps, that all are not created equally. FWIW, I'm not fully up to speed with the varieties available.
We have the 3 different types of GT150 Sealed Connectors...
-Classic uses the Metri-Pack Seals: Delphi Tool #12085270/ Sargent #3186
-Regular uses the Slightly Larger GT150 Seals, some will fit the Delphi Tool #12085270/ Sargent #3186... Others will need Sargent #1026.
-3.5 Cent. uses Slightly Smaller GT150 Seals and uses the Sargent #1026.
Is there a compendium of terminals, connectors and seals that I could browse through? Metri-Pack, Delphi, Packard, Molex....are buzz words tossed about but I can't say I know the distinction between them.
I've done my share of crimps over the years however it's more along the barrel type crimps which I'm fully outfitted for.
The open barrel stuff is more of a mish-mash for me as I've never had the need to standardize my practices. Until now.
Is there a compendium of terminals, connectors and seals that I could browse through? Metri-Pack, Delphi, Packard, Molex....are buzz words tossed about but I can't say I know the distinction between them.
I've done my share of crimps over the years however it's more along the barrel type crimps which I'm fully outfitted for.
The open barrel stuff is more of a mish-mash for me as I've never had the need to standardize my practices. Until now.
The inner diameter of the cable seals are specific to a range of wire insulation diameter. You need to buy the right cable seal for the wire you are using.
The OD of the cable seal is standardized to the type of connector it is used with, so the insulation crimps are standardized too. What can get a little tricky is there can be multiple standards within the same model name of connector.
Some of the details cannot be understood without access to the original Delphi drawings. This is where vorteciroc has been helping greatly, and I've been documenting in the LS connectors thread.
I'm starting from ground zero on every topic matter related to this harness build. You're starting from a highly experienced standpoint, you'll figure this stuff out a thousand times quicker than me.
The inner diameter of the cable seals are specific to a range of wire insulation diameter. You need to buy the right cable seal for the wire you are using.
The OD of the cable seal is standardized to the type of connector it is used with, so the insulation crimps are standardized too. What can get a little tricky is there can be multiple standards within the same model name of connector.
Some of the details cannot be understood without access to the original Delphi drawings. This is where vorteciroc has been helping greatly, and I've been documenting in the LS connectors thread.
I'm starting from ground zero on every topic matter related to this harness build. You're starting from a highly experienced standpoint, you'll figure this stuff out a thousand times quicker than me.
I understand the range implications with respect to the seals and everything. It's not unlike a barrel style crimp however there's the added element of the seals of connector bodies in general that seems to have an overabundance of crossover. Or perhaps that's more like one brand or another covering the same ground that adds to the confusion.
That said, one of my basic questions was along the lines of Weather Pack vs Metri-Pack. I found the answer to that one. I've learned that it's the shape and size of the pins themselves and subsequently the style of connector needed. Packard developed the Weather Pack and then along with Delphi, reengineered them into the Metri Pack if I understand it correctly. I guess it's pick a style and run with it. I'll thank IWISS for the handy explanation. https://iwiss.com/comparison-weather...pack-terminal/
My applications are considerably more modest than yours though. I'm not building an entire EFI harness with the many and varied connectors required. I'm more into the power distribution bit as I'm looking to clean up my well worked over engine bay wiring.
I'll agree, vorteciroc has been immensely helpful in this regard (as has the originator of this thread). I thank you both. His insights into PDM has led me down a new road of discovery. I'm still coming up to speed on that.
I'll have to re-visit the LS connectivity thread.
As for the "figure it out faster" part? I'm seeing you're miles ahead on this already. Even if it's just from a tooling standpoint! And I know there's more to it than that.
Interestingly, the industrial world I've spent a career in has little application to the automotive side of things. This is where my learning curve has started from zero basically.
That said, one of my basic questions was along the lines of Weather Pack vs Metri-Pack.
Weather-Pack shares the same cable seals with Metri-Pack 280, and the seals are usually sold under the Metri-Pack 280 name. That can be confusing.
Yeah, each family of connector has a spec for diameter of the internal cavity inside the body of the connector where the seal is stuffed in. Sometimes there are mixed seals in certain p/n connectors, but it generally follows this guideline:
3.6 mm, GT 150 Mini
4.0 mm, GT 150
5.2 mm, Metri-Pack 150
5.8 mm, GT 280
6.7 mm, Metri-Pack 280 / Weather-Pack
8.5 mm, Metri-Pack 480
9.8 mm, Metri-Pack 630 / Ducon 6.3
There are likely others but this list is all I've needed so far. I have found some of the Delphi TAXI drawings (master drawings) for these seals and that is like gold. Here is the list of Metri-Pack 280 seals I have found from those TAXI drawings. Black rows are preferred p/n's, Red rows are non-preferred or obsolete. (Cable AWG is something I added for myself based on the wire I use.) I gotta keep good records for myself or this stuff gets confusing quick....
They both have similar specs, but I have noticed that the SCT has a longer "workable" time during cool down so it's been more user friendly with larger bundles.
Never said it was entertaining!
Downside is they are rather expensive.
