A couple issues - 5.3 S10 swap
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 372
Likes: 8
From: So. WIS
A couple issues - 5.3 S10 swap OK, trying to work off all the little tuning issues on my swapped S10.
1. GAS Gauge is in/op - reads "Low Fuel" and pegged on empty. I have run the wires, put in a new neutral safety switch/gas gauge rely on the trans. Thinking that the sender may have been shorted?? So is there a way to check this without pulling the box off of the truck?
2. I am stuck in the closed loop circuit. The O2's do not operate. The harness builder and I went over everything. Wires are in the correct position at the plugs, continuity checked, O2's are brand new. Live data reads .445 on bank 1 & 2. According to the manual, this is the closed loop reading, as the number does not change. This causes a fuel dump or rich fuel condition (MPG is 17.5, should be 23-25).
The only thing I can think of is a tuning issue. Is it possible to switch off all of the O2's while tuning? The rear O2's were deleted when we did a base tune. Could all of the O2's gotten turned off???
3. Knock sensors - getting a code on these too. This is a GEN III 5.3 ('99) and is running an LS1 cam, and has the poly motor mounts. I also know that the exhaust is touching the frame on the pass side. So, can these be written out of the ECU?? That would seem to be the easiest way to remove the code (keep it from going closed loop).
The goal here is to be able to have the truck tuned. Can't do that in closed loop operation.
Thanks, Jim
1. GAS Gauge is in/op - reads "Low Fuel" and pegged on empty. I have run the wires, put in a new neutral safety switch/gas gauge rely on the trans. Thinking that the sender may have been shorted?? So is there a way to check this without pulling the box off of the truck?
2. I am stuck in the closed loop circuit. The O2's do not operate. The harness builder and I went over everything. Wires are in the correct position at the plugs, continuity checked, O2's are brand new. Live data reads .445 on bank 1 & 2. According to the manual, this is the closed loop reading, as the number does not change. This causes a fuel dump or rich fuel condition (MPG is 17.5, should be 23-25).
The only thing I can think of is a tuning issue. Is it possible to switch off all of the O2's while tuning? The rear O2's were deleted when we did a base tune. Could all of the O2's gotten turned off???
3. Knock sensors - getting a code on these too. This is a GEN III 5.3 ('99) and is running an LS1 cam, and has the poly motor mounts. I also know that the exhaust is touching the frame on the pass side. So, can these be written out of the ECU?? That would seem to be the easiest way to remove the code (keep it from going closed loop).
The goal here is to be able to have the truck tuned. Can't do that in closed loop operation.
Thanks, Jim
1-What year is your truck and does the fuel guage get its signal from the pcm or directly from the sender?
2-I would like to see an answer here,I think I'm having the same issue with my Jeep swap
3- No,you must have them.Chances are they are corroded from filling up with water over the years,you will need a pair of knock sensors and the harness/connectors
2-I would like to see an answer here,I think I'm having the same issue with my Jeep swap
3- No,you must have them.Chances are they are corroded from filling up with water over the years,you will need a pair of knock sensors and the harness/connectors
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 372
Likes: 8
From: So. WIS
Truck is an '03 S10 EXT Cab, short box. Had a similar issue with my '71 ElCo, turned out to be a broken ground wire. Was an easy fix. With this late model stuff the answer isn't as clear cut. My tank lives under the box, right by the third door, inside of the frame rail. That all means I have to pull the box again to inspect wiring, and pull the sender to manually operate the float to see if that changes anything. (Really would rather not do that). Prior to dropping on the box, I did inspect the area to be sure I had not stepped on or broken any wires. The original start had the gauge working, but lights were going crazy (wrong placement of the jumper ground at the fuse block).
This could be a PCM issue based on the jumper wire issue. I guess that we could of tripped something in the tune? Andrew, what are your thoughts?
O2's and Knock sensors - Yeah, I was figuring this to be the case. Just a PITA to remove the intake and swap them. I do have a spare set on the shelf, and did have a coolant leak when I first got the truck going. Looks like this will be a weekend job since I have the parts.
Sold a hood yesterday, looks like my buddy is going to get the money when he brings over the scanner to check the O2's and why the truck is stuck in closed loop. I'm hoping that this is all it is. With the gas gauge and the O2's acting like this, I'd think that the PCM is at fault in the tuning.
Still looking for ideas, so keep 'em coming!
This could be a PCM issue based on the jumper wire issue. I guess that we could of tripped something in the tune? Andrew, what are your thoughts?
O2's and Knock sensors - Yeah, I was figuring this to be the case. Just a PITA to remove the intake and swap them. I do have a spare set on the shelf, and did have a coolant leak when I first got the truck going. Looks like this will be a weekend job since I have the parts.
Sold a hood yesterday, looks like my buddy is going to get the money when he brings over the scanner to check the O2's and why the truck is stuck in closed loop. I'm hoping that this is all it is. With the gas gauge and the O2's acting like this, I'd think that the PCM is at fault in the tuning.
Still looking for ideas, so keep 'em coming!
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 372
Likes: 8
From: So. WIS
Restricted User
Joined: Mar 2014
Posts: 7,192
Likes: 109
From: Ohio
O2 sensors will read ~445 even if not wired at all.
Chances are, the wiring isn't correct.
Are they case ground, or isolated ground sensors?
Isolated ground sensors all have a tan (usually tan) wire that goes into a splice pack. These must be all pinned into the PCM in the correct spots to work properly.
Chances are, the wiring isn't correct.
Are they case ground, or isolated ground sensors?
Isolated ground sensors all have a tan (usually tan) wire that goes into a splice pack. These must be all pinned into the PCM in the correct spots to work properly.
Thread Starter
TECH Apprentice
Joined: May 2010
Posts: 372
Likes: 8
From: So. WIS
Tan wires Yes, has the tan wires running back to the PCM. Verified pin placement of the tan and the purple wires to the BLUE connector at the PCM. Verified wire placement to the O2's.
O2's are from a 5.7 LS1 Camaro, 2002. Got a set of 4, and tried a simple swap out, no change. Then verified wiring, the called the builder to verify @ PCM. Truck runs well, but only have closed loop operation, therefore is running rich (dumps extra fuel).
Heading to a friends house on Monday to put it on the scan tool to see what's up and go from there. Talked to him last night and he was confused too.
I do know that the ground jumper at the fuse block was in the wrong location (F7 - F8), but everything else worked at the time. Leaning towards this being the cause right now. At least I can still drive the truck right now.
O2's are from a 5.7 LS1 Camaro, 2002. Got a set of 4, and tried a simple swap out, no change. Then verified wiring, the called the builder to verify @ PCM. Truck runs well, but only have closed loop operation, therefore is running rich (dumps extra fuel).
Heading to a friends house on Monday to put it on the scan tool to see what's up and go from there. Talked to him last night and he was confused too.
I do know that the ground jumper at the fuse block was in the wrong location (F7 - F8), but everything else worked at the time. Leaning towards this being the cause right now. At least I can still drive the truck right now.
