Yeah that's the plan. I might be able to use some of the wires under the dash, but the plan was mostly just to use the wire for lights... maybe temp and oil sensor. I am keeping the Jeep computer installed and plugged in, because it looks like a lot of other stuff processes through it... I could be wrong, but the three main plugs that connect to it seem to be connected to a lot of other stuff. So ill keep it where it is and plugged in, but use the 4 wire setup to run the engine management. I'm still trying to figure out the best way to wire everything in... like with the fuel pump... I don't know if I want to just run the wire to the existing relay and see if it'll work, or if ill need to run it separate. The fuel gauge will be spliced. The speedo will work off a vss sensor that gives a sine wave that the GM needs. I think I have it figured out... I just hate wiring because it's not my strong point and I don't want to mess something up haha.
5.3 Vortec engine swap and other upgrades
- Thread starter Jeeper25
- Start date
Yeah that's the plan. I might be able to use some of the wires under the dash, but the plan was mostly just to use the wire for lights... maybe temp and oil sensor. I am keeping the Jeep computer installed and plugged in, because it looks like a lot of other stuff processes through it... I could be wrong, but the three main plugs that connect to it seem to be connected to a lot of other stuff. So ill keep it where it is and plugged in, but use the 4 wire setup to run the engine management. I'm still trying to figure out the best way to wire everything in... like with the fuel pump... I don't know if I want to just run the wire to the existing relay and see if it'll work, or if ill need to run it separate. The fuel gauge will be spliced. The speedo will work off a vss sensor that gives a sine wave that the GM needs. I think I have it figured out... I just hate wiring because it's not my strong point and I don't want to mess something up haha.
ok so quick update... I took a week off of work to try and finish this thing out because its been taking me months longer than I wanted. I've gotten everything wired up except the dash but for the most part I have a pretty good plan for that.
With the fuel pump, even though it was relayed through the GM wiring harness, I decided to just run the power wire to the Jeeps existing fuel pump relay to kick on the pump. In order to do this, I had to ground the Jeep relay because its originally grounded to the PCM and with all the original engine wires gone, the pcm wont complete the ground to keep the pump on since its not getting any sensor signals.
Keeping the original dash is definitely an option, but with the vss issues and my dash going out anyways I didn't feel like dealing with it. I novak makes a converter that converts the jeeps digital square wave into a sine wave that the gm pcm can read. some other companies might as well... maybe Dakota digital or AutoMeter but they typically have a good amount of lag due to the signal conversion.
I'll just kind of go into everything that I've gotten done this week though.
T-case rebuilt w/ SYE
T-case installed
clutch master cylinder cable installed/bled
fuel pump/tank installed
fuel lines ran
New drive shaft installed
Jeep wiring delete
GM wiring integrated
radiator installed
fan mounted
front grill mounted
vacuum lines ran
power steering cooler installed
engine tune up
oil changed in everything
Exhaust fabricated
u-joints in front shaft replaced
shifter cut and adjusted
DBW pedal installed
It's been a busy week but I got to drive it today and there is a HUUUUGE difference in drivability. I went from barely being able to hit 5th gear, to burning rubber through 2nd gear with 33 inch mud tires. The exhaust was kind of a hold me over design I made since I already had a 16 inch glass pack so I ran to AutoZone, bought a 24 inch glass pack and a few other connectors and welded it together. The exhaust on the passenger side used the original after market 2.5 inch exhaust from Pace setter that was on it I just needed about a foot of pipe and a new hanger to bridge the gap. the drivers side was where I used the glass packs. They're pretty cheap at about $24 so it goes from the down pipe, to the shorts glass pack, then the longer, and then it just turns down right after the T-case. I think I'll have them match the drivers side exhaust to the passenger side eventually with another pace setter or flowmaster muffler right after the T-case but for now it sounds pretty awesome and it works.
I have to reset the shifter. I have it leaning to far back so I cant put the center console back in but that an easy fix. Just have to cut it, adjust the angle and weld it. I have to reset the gas pedal to the right a little too because the brake pedal it hitting the brake but that's a pretty easy fix. it's been a long weekend, But ill be posting pictures of everything i did soon. In the meantime. enjoy the nearly finished product.
With the fuel pump, even though it was relayed through the GM wiring harness, I decided to just run the power wire to the Jeeps existing fuel pump relay to kick on the pump. In order to do this, I had to ground the Jeep relay because its originally grounded to the PCM and with all the original engine wires gone, the pcm wont complete the ground to keep the pump on since its not getting any sensor signals.
Keeping the original dash is definitely an option, but with the vss issues and my dash going out anyways I didn't feel like dealing with it. I novak makes a converter that converts the jeeps digital square wave into a sine wave that the gm pcm can read. some other companies might as well... maybe Dakota digital or AutoMeter but they typically have a good amount of lag due to the signal conversion.
I'll just kind of go into everything that I've gotten done this week though.
T-case rebuilt w/ SYE
T-case installed
clutch master cylinder cable installed/bled
fuel pump/tank installed
fuel lines ran
New drive shaft installed
Jeep wiring delete
GM wiring integrated
radiator installed
fan mounted
front grill mounted
vacuum lines ran
power steering cooler installed
engine tune up
oil changed in everything
Exhaust fabricated
u-joints in front shaft replaced
shifter cut and adjusted
DBW pedal installed
It's been a busy week but I got to drive it today and there is a HUUUUGE difference in drivability. I went from barely being able to hit 5th gear, to burning rubber through 2nd gear with 33 inch mud tires. The exhaust was kind of a hold me over design I made since I already had a 16 inch glass pack so I ran to AutoZone, bought a 24 inch glass pack and a few other connectors and welded it together. The exhaust on the passenger side used the original after market 2.5 inch exhaust from Pace setter that was on it I just needed about a foot of pipe and a new hanger to bridge the gap. the drivers side was where I used the glass packs. They're pretty cheap at about $24 so it goes from the down pipe, to the shorts glass pack, then the longer, and then it just turns down right after the T-case. I think I'll have them match the drivers side exhaust to the passenger side eventually with another pace setter or flowmaster muffler right after the T-case but for now it sounds pretty awesome and it works.
I have to reset the shifter. I have it leaning to far back so I cant put the center console back in but that an easy fix. Just have to cut it, adjust the angle and weld it. I have to reset the gas pedal to the right a little too because the brake pedal it hitting the brake but that's a pretty easy fix. it's been a long weekend, But ill be posting pictures of everything i did soon. In the meantime. enjoy the nearly finished product.
Longhorn84
TJ Enthusiast
It's not letting me upload videos but heres a pull I did with it. I still have the Spicer 35 so I'm afraid to dump it from dead stop, but I have peeled out into third on accident before lol. I'll make another when I put a better rear end under it. Heres my Facebook album instead
https://m.facebook.com/story.php?story_fbid=2669442723071770&id=100000182054321
https://m.facebook.com/story.php?story_fbid=2669442723071770&id=100000182054321
Grovian
New Member
Longhorn84
TJ Enthusiast
100% worth it. Especially coming from the anemic 2.5L it had. I'm having trouble keeping my foot out of the gas and its still getting 12.6 MPG lol. I'm sure if I drive like a normal person I might get closer to 18. maybe ill try it some day... maybe lol.
You might have to be logged in but I'm not for sure. I just pulled it up. I'll figure out how to post a video on here when I have time to figure it out.
You know... in case anyone gets curious. I kinda wanted to put it higher but I felt like I needed to go next to the jeep emblem. either way... might change it around later but I think I like it there for now.
Longhorn84
TJ Enthusiast
I thought about an emblem for my swap too, where did you get it?
Sent from my iPhone using Tapatalk
Sent from my iPhone using Tapatalk
I got them off Amazon. Just search "5.3l vortec emblem" and a whole array of them will pop up. I got the 16 dollar ones and I like the quality of them. But they have all kinds of colors. I actually ordered another set because I messed one up on the passenger side. I'll have one to put on the back now so people will know what passed em!
I changed the dash around. Found these pretty cool LEDs with the actual emblems and added a low oil light. Couldn't find one for the 4x4 so it's still an LED but I'll keep looking. Also got all the gauges working. I had to splice a 12v key powered 1k resistor into the input signal for the Tach but now it reads. The water temp sensor is in radiator and the oil sensor uses an adapter that replaces the stock sensor near to top back of the block.
oldb
TJ Enthusiast
Jptaylor75
New Member
Great job on the build! I frequently search for v8 swap/upgrade threads and stumbled across yours. I’m located not far away from you, in lafayette. I’ve been looking to replace my motor in my 98 wrangler with a stock 2.5 4-banger.... Would you happen to still have your old motor? If so are you looking to sell it?
Longhorn84
TJ Enthusiast
Are you looking for a 4.0? I’m about to pull mine and posted it for sale in the classifieds section
Sent from my iPhone using Tapatalk
Jptaylor75
New Member
No sir.. looking to keep it simple for myself...gonna stay with the 2.5. Thank you though!
I do, I have it setting in my driveway under a tarp so it should be fine still. Could use a new oil pan gasket but it ran fine when I pulled it. It has the larger injectors, a 4.0 throttle body with a spacer and I have the cold air intake still too. I still have the transmission too but itll need a new shifter because I chopped mine up to make the nv3550 shifter fit. It has headers too. What would you be interested in paying for it?
Woops... no damage to the ring and pinion though which is awesome. Atleast that's a cheap fix until I can do the 8.8 swap 
Jptaylor75
New Member