5.3 swap running pig rich
05-28-2012, 11:15 AM
#1
5.3 swap running pig rich just fired up my 5.3 swap for the first time and it is running incredibly rich. I am planning on converting it over to open loop speed density so I have no maf and have removed all of the factory o2's as I will just be running a wideband. it will be going turbo soon. anyways, to start it I have to hold the throttle wide open. when it does start it pours black smoke like a diesel and won't idle, I have to keep giving it some throttle. my friend was trying to set a baseline tune on it with hp tuners and just couldn't pull enough fuel from it to get it down. I actually ended up opening a vacuum port and it would somewhat idle. it would surge like a blown alcohol motor then. what am I missing here?
05-28-2012, 03:11 PM
#3
motor is a bone stock junkyard pullout from a 99 silverado, harness and pcm from 01 yukon. harness was just stripped down to stand alone via the diagrams and instructions on lt1swap.com. and initially he just turned off the VATS, and all the codes for the items that were removed. I knew it would probably be a little off, but not this bad. he also said it was still getting one code though, a bank 2 injector control. what could cause this code?
05-28-2012, 09:20 PM
#7
hmm... interesting I will have to confirm which injectors I have. I think I have the issue dialed down to the ECT. I traced the wiring but found no issues. checked grounds etc. problem is it's hard for me to tell if I make a difference now because my friend isn't here with the HPtuners to see if the ECT is reading or not if I change anything. IAT sensor was also reading -38* but I don't have an IAT sensor on it right now so that is to be expected I guess. going to double check the wiring and such again to make sure i didn't miss anything
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05-30-2012, 11:16 AM
#12
only one sensor is missing so I kinda of expected it to be a little off. but no to the degree it is. and I still can't find a reason why the coolant temp sensor shouldn't be reading. I mean the truck won't even start unless it's at WOT and then it struggles to stay running after that
05-30-2012, 07:23 PM
#13
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only one sensor is missing so I kinda of expected it to be a little off. but no to the degree it is. and I still can't find a reason why the coolant temp sensor shouldn't be reading. I mean the truck won't even start unless it's at WOT and then it struggles to stay running after that
05-30-2012, 08:10 PM
#14
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well you took off the o2 sensors which would be a fall back for the ect sensor so the computer litterally has no idea whats going on at all... what was your injector duty at idle like 60% haha
05-30-2012, 11:20 PM
#15
yeah it only runs when he has the comp on it so I don't damage anything. I want to be able to see what it's doing. not having the IAT plugged in won't make the coolant temp not read will it? I can't find any reason why it shouldn't be working. I have been kicking around the idea of throwing a pair of 02's back on it in the y pipe before the turbo. the injector duty at idle was around 20, but a quick blip of the throttle would set them to 96%
05-31-2012, 01:08 AM
#16
omgwtfhax...
so I decided, oh I'll just reconnect my bank 1&2 sensor 1's to the harness and use m y stock ls1 manifolds and y pipe for now to get it basically running. then I discover that for whatever bastard reason my harness uses a different upstream harness. it has a gray wedge shaped connector instead of the traditional square, and lt1swap.com shows they wire in differently as well. damnit, now I have to got buy a different set of o2's to put it back to closed loop. GM why can't you keep things the same and consistent? what the hell was gained by changing up these sensors?
so I decided, oh I'll just reconnect my bank 1&2 sensor 1's to the harness and use m y stock ls1 manifolds and y pipe for now to get it basically running. then I discover that for whatever bastard reason my harness uses a different upstream harness. it has a gray wedge shaped connector instead of the traditional square, and lt1swap.com shows they wire in differently as well. damnit, now I have to got buy a different set of o2's to put it back to closed loop. GM why can't you keep things the same and consistent? what the hell was gained by changing up these sensors?
05-31-2012, 01:30 AM
#18
i'm working on that now, however my information seems to be conflicting. according to the wiring schematic, the ECT sensor loops from the PCM (C1 pin 74 yellow wire) through the sensor back to a low reference which by the schematic says should be C2 pin 80 gray wire. the wire from the sensor is gray, but on the same site the PCM pinout shows no such low reference back to the pcm, and both C1 and C2 have different wires assigned to pin 80. I also confirmed this with my pcm, it matched the pinout. so, where does this other gray wire go to?
here is what I am going by:
http://www.lt1swap.com/pictures/fig_2.gif
http://www.lt1swap.com/99-02_vortec_pcm.htm
here is what I am going by:
http://www.lt1swap.com/pictures/fig_2.gif
http://www.lt1swap.com/99-02_vortec_pcm.htm
05-31-2012, 01:47 AM
#19
dammit.... found the problem... found another diagram showing where the gray wire ties in. apparently it ties in to C1 pin 41 which is listed for a trans sensor ground. thinking I wouldn't need this I swapped it over to pin 42 like it says to be able to add in an electric fan control. I know what I have to do now but not looking forward to doing it.... 
Yep... 