The Rubi Q Build

Progress has been slow but it’s coming along. Building the exhaust is fully finished. I just need to install the cats/muffler section. I wrapped and spray coated both down pipes and the cats. Hopefully that will hold some heat in.

I ended up finding an auto shifter assembly from a 2006 tj. They gave me a cable but it had a broken mount and then brought me another one. It was longer. So I actually don’t know what year it was from. But it all works. I built a bracket to mount to the bell housing that the cable bracket bolts to. From there I had to slightly modify the transmission shifter lever. I’ll add a gusset to strengthen it once I’m happy with its function. Two of the gates on the shifter need about 1/16” material removed for perfect function. I’ll do that at some point.







I used a Novak cable shifter for the transfer case. They have two T-case brackets depending on which case you have. I had them send both. Neither one worked right off. I picked the closest one and made the needed changes to mount it and mount the cable. All is well now. Shifts smooth. I need to add a switch that the shift lever will hit once in four low for the ECM. Then all the shifter stuff will be done.

She runs!!!!!!!!!!!!!!!!!!!!!!!!!

Most uneventful start up ever. Now I’m going to go inside and puke, and let the nerves calm down. 😂

Little bit of progress every day. Seems to run better the more I run it. Got the rear driveshaft installed tonight and put it in gear for the first time. Nothing happened. Found out I was still about 4 quarts low. Guess the cooler uses more than I thought. Topped it off and got forward and reverse. Found out it has no issues driving right through the brakes with the fronts sliding on the garage floor.
Only engine code right now is for a crank relearn. For whatever reason my scan tool tries to do it then quits. I’ll bring home the work scan tool and try again. I don’t want to run it much till that is done.

Anyways, here’s a photo dump of the last things I did to get it running.

Here’s the intake tube and support bracket I made. I also installed a credit card style MAF sensor on the back side, out of side as much as possible. I now know the tube is 2” too short as the filter hits the radiator support rod. I have another tube to lengthen it.


I installed a catch can. I noticed the intake was pretty nasty during the rebuild so I want to try to keep it clean.


The break in oil I am using.


Oil filter.


The radiator fan was too close for comfort so I cut the end off the water pump. I used a wet rag under the pulley on the shaft and went slow and cooled the top as I went. Then tacked it in four places. Hope it holds up. I tried two other car pumps first and couldn't make them work.


Water pump installed again.


After ten or so hoses I found these two. I needed to cut about an inch off both of them, but other than that they work great. If you are using a truck pump and Superior radiator these are your hoses.


Cold pressure hit 60 and the lowest I’ve seen is 45. I’m happy with those numbers. The other gauge is fuel. Sitting right at 59 all the time.


The bracket and switch I made/used for the 4 low signal to the ECM.


The Tap N Cruise display. I hate the box as it is very hard to mount anywhere nice. I wish it was round to fit in a gauge pod. It displays each gear, which will be handy in manual mode, as well as other info.

No fancy shenanigans here. Just simple and clean. Well dirty, but clean.



Love the stock look.


You can see the support rod hitting the filter here. Just need to move the filter out two inches. I keep forgetting to get an overflow bottle. For now a Gatorade bottle is working fine. I need to find an engine cover as well. Once I have a couple hours of driving and am satisfied the wiring is good I’ll loom it up and make it look nice. So far only one wrong wire. I wired the new MIL to crank hot instead of ignition hot. Silly me. It’s fixed now and working fine.

I’m wondering about cooling system pressure. My mind tells me to get is as low as possible to try to save the heater core. I have an 18psi cap now. I think I could get a lower one, but not sure what to try, or how much it matters. Any ideas?

What do you gain with higher pressure besides a higher boil point. Maybe a slight increase in thermal transfer. If you're not anywhere near boiling I don't see a downside to lower pressure. If you overflow the overflow tank then put the 18 back on. On the other hand just carrying a way to bypass the heater core in a pinch would ease my mind. I worry more about the radiator and plumbing that I need to keep going.

Yeah, I’ve been thinking about installing a bypass to the heater core so it wouldn’t see all the fluid, heat, and pressure during the summer months. To hopefully get more life out of it.
This brings me to the big LS debate: loop the two heater lines or plug them? Right now they are looped.

Two 3 way ball vales would allow me to either send coolant to the heater core and keep the loop going or I could close them to remove the flow to the core and keep the loop going.
I could also run two 2 way ball valves that would just block the flow all together.

I have read not to block flow. I would definitely loop.

Well this is a new one for me. I finally got it out for a drive yesterday. Discovered it’s stuck in limp mode. Looks like I’m not getting ignition power to the transmission. I need to work on that tomorrow. I’ve been pretty sick the last couple days. Not doing much today.
Anyways, it got HOT! The headers are uncovered, but from both downpipes, around the oil pan, both cat converters and to the muffler are wrapped. Doing a quick look at the tranny wires I noticed this.




Those are O2 sensor wires just to the rear of the passenger side header. I’ve never seen that happen before. Feeling around, everything seems way hotter than usual. Actual coolant temp was normal. Just seems like the engine bay was holding way more heat. Everything was heat soaked.
Now it has me wondering about putting in vents on the hood. My mind tells me it would help a ton. What’s your experience?

PS. The wiring will all get loomed once I’m satisfied everything is working right.

UNSTUCK said:

Well this is a new one for me. I finally got it out for a drive yesterday. Discovered it’s stuck in limp mode. Looks like I’m not getting ignition power to the transmission. I need to work on that tomorrow. I’ve been pretty sick the last couple days. Not doing much today.
Anyways, it got HOT! The headers are uncovered, but from both downpipes, around the oil pan, both cat converters and to the muffler are wrapped. Doing a quick look at the tranny wires I noticed this.


View attachment 175662

Those are O2 sensor wires just to the rear of the passenger side header. I’ve never seen that happen before. Feeling around, everything seems way hotter than usual. Actual coolant temp was normal. Just seems like the engine bay was holding way more heat. Everything was heat soaked.
Now it has me wondering about putting in vents on the hood. My mind tells me it would help a ton. What’s your experience?

PS. The wiring will all get loomed once I’m satisfied everything is working right.

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How many PSI are you running your O2's at .
I have some ceramic coated headers from some cool guy. Those headers and the JCR High line fender vents keep my under hood temps down. When the doors are off and the radiator fan comes on, you can feel the hot air exiting the fender vents. They function way better than I thought they would.

glockman said:

How many PSI are you running your O2's at .

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Sure is strange. If anything wouldn’t it just keep shrinking? Or split open once it shrinks as far as it goes.

I’m stuck with my headers but would consider wrapping them if need be.

I don’t see high lines in this build either. I like it the way it is.

I’ll try some heat resistant loom and see where it goes from there.

funny, I was just watching this video earlier today. Thermal image of jeep hoods:

YouTube Video

I pulled the TCM wire connector tonight. I was able to confirm both 12v battery and ignition voltage on their respective wires. Could not see any issues with the pins on either side. I plugged it back in and went for a drive. It shifted great! Definitely needs more tuning, but we’re making progress again.

Little more progress. I’ve been fighting a long crank time (3-4 seconds) and a cam sensor code. Turned out I had the 5v reference and the cam signal wires reversed. What’s worse is that I actually wired the solid blue reference to the blue/white signal wire when I was shortening them. In my defense that white tracer is barely noticeable. 😂

Bob with Tap-N-Cruise is working with me to resolve the tap shift error I’m getting now. He’s checking calibration numbers for the right software. Hopefully that will be easy.

I need to reinstall the skid plate and put some miles on it. My tags expired in July so I’m living on the edge at this point.

Dyno tuning is scheduled again for this Wednesday. Hopefully it will be a done deal by then. I then need to rewrite the VIN somehow and then it should pass emissions. We’ll see.

Ok, so back to limp mode. It happens every time I start the engine. It’s a P2534 code which is general for a particular module is not seeing ignition voltage. In my case the code is being requested my the TCM. There’s not a lot out there about this issue. A few guys have talked about it on LS1Tech and HPTuners, but there doesn’t seem to be a definitive answer.

Supposedly the issue is actually happening when I turn the engine off. The way I wired the ignition hot to the transmission, it turns off immediately when I turn the key off. The ECU technically does the same but keeps itself powered up for a few seconds while it goes through its shutdown procedure. At this time it sees the voltage has already dropped out from the transmission and doesn’t like it and the code gets set.
My problem with this is that my scan tool shows 0 ignition volts all the time at the transmission. It does see ignition voltage at the ECU though. I know I have ignition voltage because as soon as I clear the code the transmission functions perfectly through all the gears, minus tap shift, which I think is its own issue.

The ECU controls the “powertrain relay” which I did not take advantage of. Supposedly the ecu will turn this relay off when it finally turns itself off. Wiring ignition power through this circuit could solve the issue, but doesn’t explain why I never see voltage.

Another probable cause is the “accessory wake up” circuit. Most people seem to think this is not needed. As I understand it the BCM sends this signal all over the place to turn things on. My transmission has one of these wires. I have no BCM so didn’t bother with it. I read of a guy who wired this wire to his ignition wire and his limp mode went away.
This kind of makes sense to me. My TCM is functioning, but doing so while “asleep” that’s why it doesn’t show ignition voltage while running. It may also explain why I don’t see transmission fluid temp. I believe that sensor is inside the transmission so I should see it on the scan tool. Getting 12v to this would be much easier than running a powertrain relay. I just hate to guess on this as I can’t find actual information from GM on how this circuit works. Just want to verify the trans does need to see 12v here and not like ground or maybe even 5v.

Have you tried the 3 day ~$22 subscription to GM/AC Delco service information to get the full wiring diagrams and troubleshooting? I've been reading the crap out of it for thinning down the harness on the MG Midget ecotec swap this weekend. It's been a huge help in figuring out what can go, what must absolutely stay, and the control polarity for different circuits.

GM has some good theory of operation write ups about each specific area and how it is supposed to working. Not trying to insult anyone's intelligence, but it basically walks you thru what happens from the ignition switching on, until it's off again. I would think that could help you with defining the accessory wake up functions and if things are 12 (+) or (-).

If you go this route, download EVERYTHING you can for your drivetrain. If it won't let you download your can usually do print to .pdf screenshots.

I have full access to alldata. I didnt think about diving into their theory stuff. Most of their stuff comes right from the manufactures. That’s a good idea though and will keep it in mind if I don’t have something solid by Tuesday.
And don't worry about insulting my intelligence. I’m not smart enough to ever feel insulted.

At the dyno shop right now….. 😬

2

UNSTUCK said:

At the dyno shop right now….. 😬

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243 HP! 🤣

Probably. No full throttle runs yet. Just a few part throttles.

And I hear a nasty rattle when he’s coasting it. 😕