Started on My LS1/5.7 swap, into My 01 XJ

[jamiemac]

Yep, the LS1 PCM will most likely do a fine job of running the A/C, but having to use both PCMs and make a spot for both, just wasn't sitting right in My mind. There's definitely more than one way to skin this cat, though, and I'm the farthest thing from an expert. I'm still in the process of stripping down the Jeep harness to the bare essentials. As a matter of fact, back to work I go.

 

[Hoooper]

Yep, the LS1 PCM will most likely do a fine job of running the A/C, but having to use both PCMs and make a spot for both, just wasn't sitting right in My mind. There's definitely more than one way to skin this cat, though, and I'm the farthest thing from an expert. I'm still in the process of stripping down the Jeep harness to the bare essentials. As a matter of fact, back to work I go.

yeah, like I said if youre planning to run aftermarket gauges the Jeep PCM has a lot less value in it. I think the same goes for if you had a pre-96 cherokee (before CCD was running most/all of the gauges). Have you considered whether your interior items aside from HVAC will work? I have seen some postings that suggest a bunch of their interior lights and such dont work after removing the Jeep PCM. Dont know for sure if thats the case though

 

[John D]

The only thing I noticed that doesn't work after the Jeep PCM delete is the rear defogger and I'm not even sure that worked before.

 

[jamiemac]

I'll look over the defogger diagrams, tonight. I think it's controlled by the BCM.

 

[Hoooper]

if you look over the pinouts for the 96 diagram the only things with any effect on the interior are the CCD bus and the A/C controls. Maybe people who reported losing interior functions also pulled the BCM not knowing thats what it was? The 2000-2001 PCMs appear to maybe be different but I would be surprised if Jeep decided to just randomly throw some extra controls on the PCM when they were already handled by the BCM which was still there.

 

[cjlagos]

Going over some wiring diagrams, and have determined that the AC system will operate without the PCM. You just have to use ouput power from the AC request switch to send power to the AC clutch relay, while going thru the low & high pressure switches. Power from the high pressure switch will also be sent to either a fan relay, or to an input for a fan controller, which is what I;ll be using.

Thanks to John D for his insight that got Me to thinking, otherwise I's still be messing with the Jeep PCM, and that was slowing Me down.

I'm doing the same thing and it's how the factory system is wired/controlled (with power in series through the pressure switches.)

Just replace the Jeep PCM in the circuit with a relay and you can use all the factory wiring and AC clutch relay in the fuse box.

Use C22 (Pin 22 in C3) to trigger a relay that switches ground to C13 (Pin 1 in C3)which is the ac clutch relay trigger wire that the PCM grounds to engage the clutch. This way you can use the factory AC clutch power wire in Connector C108 into your A/C compressor. (Same connector with the starter solenoid control).

I am controlling fans with the Factory GM computer so using C48 (Pin 13 in C3) as AC engage signal to the GM computer so it will turn fans on automatically with AC.

 

[jamiemac]

I'm doing the same thing and it's how the factory system is wired/controlled (with power in series through the pressure switches.)

Just replace the Jeep PCM in the circuit with a relay and you can use all the factory wiring and AC clutch relay in the fuse box.

Use C22 (Pin 22 in C3) to trigger a relay that switches ground to C13 (Pin 1 in C3)which is the ac clutch relay trigger wire that the PCM grounds to engage the clutch. This way you can use the factory AC clutch power wire in Connector C108 into your A/C compressor. (Same connector with the starter solenoid control).

I am controlling fans with the Factory GM computer so using C48 (Pin 13 in C3) as AC engage signal to the GM computer so it will turn fans on automatically with AC.

That's a great way to do it! I'm using a Dakota Digital fan controller because of the flexibility in changing fan temp operation, as well as the run time after ignition shutoff. It also lets Me run the Taurus dual speed fan with a little more control over the start up of the high speed. I'll report on how it does, when it's up and running.

 

[Hoooper]

If you use a good self tuner/editor you can choose the temperatures for the fans to come on. There are two settings so you can pick a high/low setting, multiple fan staging, etc. Getting a tuner opens up a lot of doors for what you can do with just the PCM

 

[jamiemac]

A little to report today. Got both Novak engine mounts bolted on the frame. They are solid as hell. Cranking down those bolts wore My old keister out, and the weather is really crappy, so I knocked off for the day. I'm going to start back on the wiring, as soon as some supplies I have on order arrive, and the weather gets a little better, as in no gale force winds, and sideways rain.

 

[jamiemac]

The weather is just too darned crazy to do anything with the XJ. I can work in the rain, because My shop is under a big carport, but the lightning & wind is keeping Me inside. I'll report further when there is some progress.

 

[jamiemac]

I worked on installing the Novak transfer case cable shifter. The mounting plate that bolts to the floorboard/tranny tunnel is well made, but mine needed some massaging to get it the way I wanted it. I figure it's impossible to make these things fit all XJs sight unseen. First thing I did was mount it with the cable installed to see how it lined up. You will see by the red line I put on the pic, that it was pretty far off in relation to the shifter. I had to cut the mounting arm off and re weld it back in place. That took about an hour, and wasn't really that much trouble. I also bought some nylon spacers, about 3'8" thick, to mount the 4 corners of the plate to. That gave a little more space between the floorboard, and the plate. Overall, it was a hell of a lot easier to buy this unit, and modify it to fit, than building something from scratch.

 

[jamiemac]

More work on the wiring today and over the past few days. First, I started making some brackets to mount the ABS Plastic sheet I'm using to hold the computer, and relay box. I had a different design in mind, and was bout halfway finished with it, and changed My mind.

Here are the first 2 brackets of 3 brackets.



Here is the general layout of the PCM, and relay box. Nothing is fastened down yet in this shot.

 

[jamiemac]

I'll be getting the wiring harness routed next, then I'll start on the tranny setup, and Advance Adapters tailshaft install. I decided not to run the PCM and fuses inside, for a couple of reasons. Reason 1 was because I didn't want to run the extra wire needed. Reason 2 was for ease of access when the XJ is loaded to the roof with camping gear. I can still access the fuses, and relays without unloading the cargo.

 

[jamiemac]

Sorry about the year break in this thread with no updates. Heath and family issues kind of scattered my brain a little, and I knocked off this build till spring of this Year. I got back to it, and I'll start posting some updates soon.

 

[jamiemac]

So, I left off with the wiring to start on. I eliminated the CryCorp PCM all together, and began the wiring in of my GM unit. The wiring info over at http://lt1swap.com/ was a huge help, and all the info I ran across was accurate & well presented. I'd like to see the site owner get rid of the black background though. Printing stuff from there used a ton of black ink.
I found a PCM bracket on eBay, that's for a S10 truck, I think. It worked great, and didn't require a lot of thought to mount underhood. I just got some nylon spacers at Home Despot, & put it on the right inner fender. I changed the mount 2 times since the previous pics were taken. The F-body bracket wasn't making me feel warm & fuzzy.

 

[jamiemac]

About October of 2014, I got the tranny rebuilt with the shortened Advance Adapters shortened output shaft, and also replaced all the clutches & steels with a TCI rebuild kit. It also included 3 different shift kits. Street, strip, & RV. I went with the RV kit, and the trans already had the Corvette servo, so that firms up the shifts also.

Beast sunshell installed as a preventive measure.


Drum doing in


Teflon seals going on.


Advance's transfer case adapter installed. It also allowed me to clock my Tcase up a notch. Gave lots of clearance'

 

[Johnnie Walker]

That looks nice. When I do an LSx swap in my XJ, if I keep it auto, I really want to run a 6L80-E. More gear selection, and the manual shift mode is nice. I would like to get one of those arcade-style shifters. With an indicator display.
http://www.colecovision.dk/images/up-down-shifter.jpg

 

[yossarian19]

That looks nice. When I do an LSx swap in my XJ, if I keep it auto, I really want to run a 6L80-E. More gear selection, and the manual shift mode is nice. I would like to get one of those arcade-style shifters. With an indicator display.
http://www.colecovision.dk/images/up-down-shifter.jpg

I spoke to a Chevrolet rep at SEMA a few years back and asked why they didn't offer a crate 6 speed. His response was that size was prohibitive, weight was abundant, performance gains without tailored programming were marginal and cost was high.

Another option and possibly a better one would be to run a 6 speed valve body in a 4L80E

 

[Johnnie Walker]

I spoke to a Chevrolet rep at SEMA a few years back and asked why they didn't offer a crate 6 speed. His response was that size was prohibitive, weight was abundant, performance gains without tailored programming were marginal and cost was high.

Another option and possibly a better one would be to run a 6 speed valve body in a 4L80E

Having discussions with heavy line and master technicians at previous gm dealers I have worked for. They pretty much said that the gm 6 speed auto is second only to the allison.
I trust their word more, being as they see them on a regular basis in the real world. Vs, some rep, whom has unknown to me certification and actual experience with the part. Not to say that they do not, but without knowing what does "their word" really mean?

 

[yossarian19]

Errm,
heavy line / master tech's know the transmission as durable and well fit to an OEM application.
Not the same as swap or aftermarket friendly.
For all I know a 6.0 / 6L90E would work tits in any vehicle you cared to try it in but when the guy in the Chevy shirt is explaining why they don't plan to sell them aftermarket, I'm willing to take his word for it.