Man it seems like its been forever since I've made a post on here, but now is the time to throw it to the elders and see what they think on the matter.
I'm working on the 92 in my sig, and recently blew the little v6. After working the living piss out of that engine, and pushing it to its limits, she finally gave it up. Now came the v8 swap I had been itching to do forever. Just finished the swap last weekend and i could not have asked it to go any smoother. (perks of having so many new parts and old tbi parts from multiple engines laying around to pick from) I've just about all the "kinks" worked out with the exception of a couple.
Initially codes 13 and 43 were always setting, and I could feel a drastic hesitation or limit in power when I would get in the middle of it. And it always seemed to have a miss or just a rough idle.
Code 43 was expected as, in the 5 years I've owned the truck the knock sensor has never been installed or hooked up. Code 43 would always set intermitantly (hardly ever) and usually during a pull uphill. During its previous 3 engine swaps, Ive searched the harness for the pigtail and/or clipped wire with no success for the sensor itself. And the knock circuit has always been that "oh I'll just fix it later", just to never end up getting corrected. During the other night, I installed a knock sensor and pigtail temporarily cutting the sensor feed wire at the ESC module, and code 43 has not returned.
Code 13 is new, and seems to be the albatros around this swap so far.
Initially I used the single wire o2 that was installed on the v8 that I swapped in (motor was a 20k mile Jasper dealer warranty replacement pulled from a late 87-89ish chevy boxtruck/C+C). According to the snap on brick, o2 values stayed at 438, 434, and 451 and the system stayed in open loop. Swapped sensors for the o2 that came out of the blown 4.3. The tip didn't appear to be in the best shape, but I knew that it worked in the truck prior, so it would at the very least I could get an idea of what was going on. At first everything seemed fine, the engine warmed up, it went right into closed loop, and o2 was fluctuating just like it should. Truck ran like an absolute TOP! No stalling, no hesitation, HOWEVER... Around the end of the test drive it kind of seemed to be running a little "doggy" again, and when I glanced at the readings, it was back into open loop and o2 readings steady at 438, 434, 451.
Yesterday I took it on about a 100 mile(one way) trip to Clovis with the scanner, and was pleasantly surprised to see that every time I checked, it was running closed loop the whole way and even held while climbing the "cap rock". I get to Clovis and its back to open loop. Kinda checked things over in the parking lot and I could not pin point it, but I kept hearing a random spark, almost like a plugwire was arcing to ground every once in a while. I looked, and looked, moved wires around and nothing. Began driving back, and right into closed loop it went, and stayed the whole trip (or atleast everytime I checked or was watching). Had to go get parts for another vehicle 20 miles out so I ended up turning as soon as it got home. Heading out of town, it was in open loop, until I got on the highway. Went into open loop and stayed until I got to where I was going. Same coming home. When I pulled up, I watched the scanner and it was still in closed loop. Sat there and let it just idle, and within 1-2 minutes it switched to open loop and same readings of 438, 434, and 451. That tells me the that it goes open loop at idle, or low speeds, and closed loop at highway speeds.
Being at idle and low speeds, does this indicate a minor vacuum leak causing the o2 to have issues?
OR....
I am running the 1227747 ECM since my 92 is 5 speed, the 4.3 ECM I pulled is 16144288. All data as well as ANY other reference material I can dig up indicates that BOTH of these ECM's only have ONE o2 (single wire) provision. Whereas they show a PCM of the same year to have a single wire o2, as well as a heated o2. My 92 has ALWAYS had a single wire o2 in the manifold, and a 3 wire heated y-pipe o2 pre-cat.
...Unless the harness was changed(its a possibility since the engine had been replaced before I ever bought it, there is a possibility that somebody had swapped harness too since this harness had a smog pump pigtail, and I don't believe that this is a smog truck) why would it have 2 sensor inputs with an ECM that only is able to monitor 1?
Even at that the 1227747 computer only has one o2 provision, so it possible that both of my o2's are sending conflicting data to the ECM? (meaning I would eliminate the downstream o2 all together)
Alternate research has also indicated that an o2 reading of .438 is basically a pre-determaned voltage the ECM sends when the sensor is not hot enough to register, which tells me that I just have a lazy o2 and I just need to replace it.
Then I keep seeing about a 3 wire o2 conversion to help with faster closed loop, and I'm curious if this would be my route that I go if in fact I do need to replace the o2.
At first start of the engine after the swap, I could hear a HUGE vacuum leak, but I was also still running with the 4.3 injectors just so i could start it, so it ran like crap anyway. Next days test drive, after swapping in the 5.7 injectors(entire throttle body and sensors are from the 4.3, all I swapped were injectors) it would stall out and die everytime I came to a stop, or throttled down from a hard decel. B12 showed something around the TPS/IAC area but I never could locate it. I did pull the EGR vacuum line and plug it, and that seemed to fix the stalling and dying. But i can still hear a hint of a vacuum leak around that area. It almost sounds like its around the MAP port at the back of the TB. No vacuum leak symptoms that I can notice are apparent, so it makes me wonder if I'm just nut
Something else I noticed with the scanner, and this has been all time, I have proper voltage readings for the TPS, but right next to that on live data, it shows TP% 0. It reads 0 all time with pedal depressed or idle, under no load and under full load. Is the Snap On brick and OBD1 system just too inadequite to register throttle % or do i have a faulty sensor?
.....just a side note
EGR valve - (from)donor v8
MAP - donor v8
TBI injectors - donor v8
CTS - donor v8
Coil - donor v8
EGR sol. - 4.3
o2 (b1s1) - 4.3
o2 (b1s2) - 4.3
TPS - 4.3
IAC - 4.3
FPR spring - 4.3
my 4.3 TB is already lightly modded, and is also the same CFM of the 5.0/5.7 TB. That was the reason for just swapping injectors only.
What do yall make of it?
I'm working on the 92 in my sig, and recently blew the little v6. After working the living piss out of that engine, and pushing it to its limits, she finally gave it up. Now came the v8 swap I had been itching to do forever. Just finished the swap last weekend and i could not have asked it to go any smoother. (perks of having so many new parts and old tbi parts from multiple engines laying around to pick from) I've just about all the "kinks" worked out with the exception of a couple.
Initially codes 13 and 43 were always setting, and I could feel a drastic hesitation or limit in power when I would get in the middle of it. And it always seemed to have a miss or just a rough idle.
Code 43 was expected as, in the 5 years I've owned the truck the knock sensor has never been installed or hooked up. Code 43 would always set intermitantly (hardly ever) and usually during a pull uphill. During its previous 3 engine swaps, Ive searched the harness for the pigtail and/or clipped wire with no success for the sensor itself. And the knock circuit has always been that "oh I'll just fix it later", just to never end up getting corrected. During the other night, I installed a knock sensor and pigtail temporarily cutting the sensor feed wire at the ESC module, and code 43 has not returned.
Code 13 is new, and seems to be the albatros around this swap so far.
Initially I used the single wire o2 that was installed on the v8 that I swapped in (motor was a 20k mile Jasper dealer warranty replacement pulled from a late 87-89ish chevy boxtruck/C+C). According to the snap on brick, o2 values stayed at 438, 434, and 451 and the system stayed in open loop. Swapped sensors for the o2 that came out of the blown 4.3. The tip didn't appear to be in the best shape, but I knew that it worked in the truck prior, so it would at the very least I could get an idea of what was going on. At first everything seemed fine, the engine warmed up, it went right into closed loop, and o2 was fluctuating just like it should. Truck ran like an absolute TOP! No stalling, no hesitation, HOWEVER... Around the end of the test drive it kind of seemed to be running a little "doggy" again, and when I glanced at the readings, it was back into open loop and o2 readings steady at 438, 434, 451.
Yesterday I took it on about a 100 mile(one way) trip to Clovis with the scanner, and was pleasantly surprised to see that every time I checked, it was running closed loop the whole way and even held while climbing the "cap rock". I get to Clovis and its back to open loop. Kinda checked things over in the parking lot and I could not pin point it, but I kept hearing a random spark, almost like a plugwire was arcing to ground every once in a while. I looked, and looked, moved wires around and nothing. Began driving back, and right into closed loop it went, and stayed the whole trip (or atleast everytime I checked or was watching). Had to go get parts for another vehicle 20 miles out so I ended up turning as soon as it got home. Heading out of town, it was in open loop, until I got on the highway. Went into open loop and stayed until I got to where I was going. Same coming home. When I pulled up, I watched the scanner and it was still in closed loop. Sat there and let it just idle, and within 1-2 minutes it switched to open loop and same readings of 438, 434, and 451. That tells me the that it goes open loop at idle, or low speeds, and closed loop at highway speeds.
Being at idle and low speeds, does this indicate a minor vacuum leak causing the o2 to have issues?
OR....
I am running the 1227747 ECM since my 92 is 5 speed, the 4.3 ECM I pulled is 16144288. All data as well as ANY other reference material I can dig up indicates that BOTH of these ECM's only have ONE o2 (single wire) provision. Whereas they show a PCM of the same year to have a single wire o2, as well as a heated o2. My 92 has ALWAYS had a single wire o2 in the manifold, and a 3 wire heated y-pipe o2 pre-cat.
...Unless the harness was changed(its a possibility since the engine had been replaced before I ever bought it, there is a possibility that somebody had swapped harness too since this harness had a smog pump pigtail, and I don't believe that this is a smog truck) why would it have 2 sensor inputs with an ECM that only is able to monitor 1?
Even at that the 1227747 computer only has one o2 provision, so it possible that both of my o2's are sending conflicting data to the ECM? (meaning I would eliminate the downstream o2 all together)
Alternate research has also indicated that an o2 reading of .438 is basically a pre-determaned voltage the ECM sends when the sensor is not hot enough to register, which tells me that I just have a lazy o2 and I just need to replace it.
Then I keep seeing about a 3 wire o2 conversion to help with faster closed loop, and I'm curious if this would be my route that I go if in fact I do need to replace the o2.
At first start of the engine after the swap, I could hear a HUGE vacuum leak, but I was also still running with the 4.3 injectors just so i could start it, so it ran like crap anyway. Next days test drive, after swapping in the 5.7 injectors(entire throttle body and sensors are from the 4.3, all I swapped were injectors) it would stall out and die everytime I came to a stop, or throttled down from a hard decel. B12 showed something around the TPS/IAC area but I never could locate it. I did pull the EGR vacuum line and plug it, and that seemed to fix the stalling and dying. But i can still hear a hint of a vacuum leak around that area. It almost sounds like its around the MAP port at the back of the TB. No vacuum leak symptoms that I can notice are apparent, so it makes me wonder if I'm just nut
Something else I noticed with the scanner, and this has been all time, I have proper voltage readings for the TPS, but right next to that on live data, it shows TP% 0. It reads 0 all time with pedal depressed or idle, under no load and under full load. Is the Snap On brick and OBD1 system just too inadequite to register throttle % or do i have a faulty sensor?
.....just a side note
EGR valve - (from)donor v8
MAP - donor v8
TBI injectors - donor v8
CTS - donor v8
Coil - donor v8
EGR sol. - 4.3
o2 (b1s1) - 4.3
o2 (b1s2) - 4.3
TPS - 4.3
IAC - 4.3
FPR spring - 4.3
my 4.3 TB is already lightly modded, and is also the same CFM of the 5.0/5.7 TB. That was the reason for just swapping injectors only.
What do yall make of it?
