Rebuilding the 5.3 in my 02 Yukon! Need advice/tips!
- Thread starter Nozbich
- Start date
Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
I need some help boys. I just got mostly everything back together minus the MAF sensor, intake tube, and X-Link to run the LS3 TB. When I try to crank it up, it acts like it wants to fire but no luck.
I checked spark on both sides and it’s good, tested fuel pressure at the rail and it’s 58 psi, charged my battery all the way. I checked my injectors using a light and they are all good. I also went over all the grounds, cleaned them, and did the Big 3 upgrade.
I unplugged the fuel pump relay and checked oil pressure and it was 60 psi on the gauge in the truck. With the relay removed, I tried spraying some starting fluid in the intake and it sounded like it wanted to crank. Any thoughts on what else I could check?
I checked spark on both sides and it’s good, tested fuel pressure at the rail and it’s 58 psi, charged my battery all the way. I checked my injectors using a light and they are all good. I also went over all the grounds, cleaned them, and did the Big 3 upgrade.
I unplugged the fuel pump relay and checked oil pressure and it was 60 psi on the gauge in the truck. With the relay removed, I tried spraying some starting fluid in the intake and it sounded like it wanted to crank. Any thoughts on what else I could check?
Marky Dissod
Full Access Member
If you're not in Speed Density mode / if you're in MAF mode, but you don't properly connect the MAF to the intake, I wouldn't expect it to start properly if at all.
That was it!!!!!! You’re the ******* man!
I finally got my throttle body hooked up. I had a hard time finding any information on this. For anyone that sees this in the future, if you have an early 00-02 DBW truck/SUV. You DON’T need an X-Link or LS3 TB, use the LS2 DBW TB and an adapter. It’s way cheaper and achieves the same thing.
Here is a couple pics of my “expert” fabrication skills to get the TB and Air Intake Hose to work, without hitting the clutch fan. Also waiting on my O2 sensors and Hose Coupler to finish connecting to the Air Box.
Here is a couple pics of my “expert” fabrication skills to get the TB and Air Intake Hose to work, without hitting the clutch fan. Also waiting on my O2 sensors and Hose Coupler to finish connecting to the Air Box.
Attachments
strutaeng
Full Access Member
Great! Thanks for the update!
Another update boys,
I got my intake hose hooked up and O2 Sensors in. I got my hands on a MPVI2 and was able to change some things around to be able to get the Yukon running half way decent. This is all brand new to me but using HPTuners hasn't been rocket science by no means. I also managed to recharge the A/C so it's blowing nice and cold. Here is a video of me driving it around to do some break-in mileage before the first oil change.
I got my intake hose hooked up and O2 Sensors in. I got my hands on a MPVI2 and was able to change some things around to be able to get the Yukon running half way decent. This is all brand new to me but using HPTuners hasn't been rocket science by no means. I also managed to recharge the A/C so it's blowing nice and cold. Here is a video of me driving it around to do some break-in mileage before the first oil change.
In your comment about the throttle body, are you saying that there is a 4 bolt throttle body for use on a newer style NNBS/TBSS intake manifold that also has the same plug end as a Gen 3 truck intake throttle body? It's my understanding that the reason for the X-Link is to mate the newer 4 bolt throttle body plug connector to the Gen 3 truck intake plug connector. I don't remember off the top which is which....but one is 6 wires and the other is 8 wires.
What vehicle LS2 throttle body did you use? Car or truck LS2? What adapter are you referencing and what is the purpose of the adapter....Is it to bolt to the intake, or for the wiring 6-8 wire adaptation? Thanks
So I took some pictures of everything for ya and I'll try to explain this in the least autistic way possible. I originally was going to run an LS3 throttle body and an X-Link to accomplish the 90mm TB & GMT900/TBSS intake swap.
BUT, the problem is the 99-02 and 03-07 vehicles DBW TB's are different. On 99-02 vehicles with a DBW system, has 3 connectors (6 wire) while 03-07 DBW only has 1 connector (8 wire). I got lucky to end up with the 3 connectors (6 wire). I ended up having to get a silver-blade LS2 DBW TB (mine is out of a C6 Corvette).
I also got this adapter from: Warr Performance that works specifically with the LS2 DBW TB's and the 99-02 vehicles. Here is the way I wired it up on my yukon:
I hope this helps if you are running into the same issue!
Last edited:
West 1
Full Access Member
- Joined
- Jan 20, 2023
- Posts
- 419
- Reaction score
- 817
Wow, the engine sound like you should be headed to the drag strip. Did you increase the stall speed on the torque converter? I would think the factory design would be tight for that camshaft. Nice work getting it all back and running again.
strutaeng
Full Access Member
Sweet! That's awesome!
Tuning is not my thing but I've messed with HPT here and there, just doing basic things like gear ratio change, reflashing and stuff like that.
Is your speedometer not working? Why is that?
Congratulations on the engine build. Looks like you did great!
Edit: what pistons did you go with? Or did I miss that on your posts?
Tuning is not my thing but I've messed with HPT here and there, just doing basic things like gear ratio change, reflashing and stuff like that.
Is your speedometer not working? Why is that?
Congratulations on the engine build. Looks like you did great!
Edit: what pistons did you go with? Or did I miss that on your posts?
Last edited:
Hahaha I haven't got the exhaust finished on it yet. It's just running out the catless y-pipe currently. I haven't touched the tranny at all yet, I see myself having to do that next for sure. I ended up going with a Truck Norris Cam and it works great.
I'm still watching videos on HPTuners to get my stuff dialed in. I'm still trying to diagnose the reason why my speedo isn't working. I replaced the Vehicle Speed Sensor (VSS) at the transmission, all new wheel hubs/bearings that came with sensors on them, and it is getting signal to the PCM because it reads on VCM Scanner. If I figure it out, I'll post the reason why it wasn't working here. I ended going with these: Summit Racing Forged Pistons
