Ls1 problems
11-01-2008, 01:40 PM
#1
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
Ls1 problems I have just turned on my LS1, 4l60e tranny, that I have fitted into my 240sx, but I'm having a couple of problems... here they are:
My car feels rich in low rpms in first gear, its as if its wanting to redline but then suddenly on 2500rpms drives normally, (u all probably know how it feels when ur car is rich down low) Things not yet done on my car are, PCV system, its broken from nearly everywhere... I need a new one... my second problem is that I don't have 02 sensors yet... (which one is a more relevant issue to my problem)
My second problem is that I have installed my Fan outside of the normal operating system of the ECU, so I have an external temp sensor which activates my fan, does that harm or reduce anything in my car?!
(my speed sensor isnt plugged, so it ain't shifting over from 1st gear)
My car feels rich in low rpms in first gear, its as if its wanting to redline but then suddenly on 2500rpms drives normally, (u all probably know how it feels when ur car is rich down low) Things not yet done on my car are, PCV system, its broken from nearly everywhere... I need a new one... my second problem is that I don't have 02 sensors yet... (which one is a more relevant issue to my problem)
My second problem is that I have installed my Fan outside of the normal operating system of the ECU, so I have an external temp sensor which activates my fan, does that harm or reduce anything in my car?!
(my speed sensor isnt plugged, so it ain't shifting over from 1st gear)
11-01-2008, 08:41 PM
#4
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
ok what about my temp sensor, the one on drivers side head... I have that plugged in and attached to my ECU, but my fans are being triggered from an outside temp sensor... is that a problem? does that cause any complications?!
11-01-2008, 09:32 PM
#6
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
I didn't tune my car in anyway... I just installed the engine, and auto tranny, and removed VATS using HP tuners... nothing else... I didn't touch any tunning part... so what Im aiming at is a stock drivable LS1 on my 240sx... so what do u think? I should remove the 02 sensors using HP tuners? or should I just buy 02 sensors and install them? (don't forget I have no mufflers nor any catalizers only stright pipes, won't that burn my 02's? or in other words won't that render my 02's useless...?!
11-01-2008, 09:35 PM
#7
wrong - any OBDII car, and most pre-OBDII cars, need upstream oxygen sensors. they monitor the air fuel ratio, or more correctly, they monitor the presence of unburned oxygen in the exhaust, and report their findings back to the PCM/ECU.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
Trending Topics
11-01-2008, 09:38 PM
#8
without o2's its running in open loop i think. best thing to do is to install 02's or get a tune that works without them. the computer is trying to use 02's to figure the fuel trim, but without them it just thinks they are broken.
the temp sensor thing is fine, the computer may be commanding the fans to switch on, it doesent know they arnt there though, no harm.
the temp sensor thing is fine, the computer may be commanding the fans to switch on, it doesent know they arnt there though, no harm.
11-01-2008, 09:45 PM
#9
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
wrong - any OBDII car, and most pre-OBDII cars, need upstream oxygen sensors. they monitor the air fuel ratio, or more correctly, they monitor the presence of unburned oxygen in the exhaust, and report their findings back to the PCM/ECU.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
second question, won't my 02's burn or read incorrectly If I have only straight pipes?!
11-01-2008, 09:48 PM
#10
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
without o2's its running in open loop i think. best thing to do is to install 02's or get a tune that works without them. the computer is trying to use 02's to figure the fuel trim, but without them it just thinks they are broken.
the temp sensor thing is fine, the computer may be commanding the fans to switch on, it doesent know they arnt there though, no harm.
the temp sensor thing is fine, the computer may be commanding the fans to switch on, it doesent know they arnt there though, no harm.
11-01-2008, 09:59 PM
#11
yes the rear 02's are just to check that the cats are working. and i have straight pipes running to mufflers. as long as you have at least some pipe after the 02's they should be fine. i have heard that open headers can hurt the 02's, but thats only like 4 inches of pipe, so more than that should keep the 02's safe.
11-01-2008, 10:20 PM
#13
TECH Apprentice
Join Date: Jan 2006
Location: Phoenix, AZ
Posts: 369
Likes: 0
Received 0 Likes
on
0 Posts
wrong - any OBDII car, and most pre-OBDII cars, need upstream oxygen sensors. they monitor the air fuel ratio, or more correctly, they monitor the presence of unburned oxygen in the exhaust, and report their findings back to the PCM/ECU.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
the ECU cannot enter closed loop fuel mode without ready status from many sensors, two of which are the upstream 02s. without upstream o2s, the car will be stuck in open loop fuel mode and be running extremely rich, thinking it is still cold and trying to warm up. it could possibly even figure out after a bit of time there is an error in the upstream 02s and enter fault/protect mode, and run extremely poorly, if at all.
your tuner can turn off the rear or downstream 02s, which monitor the presence of unburned oxygen molecules after the catalytic converters. these can be turned off or to status not ready with a tuner and not have any drive ability issues on the car because they are largely an emissions related device, not so much a fuel trim calculator.
the only way you could get the car to run without upstream o2s is with aftermarket upstream 02s feeding the pcm signal (which is upstream 02s anyhow) or with a completely standalone engine management system programmed to run constantly in open loop and never look for upstream 02 signal.
having no 02 sensors will clear up 99% of your driveability symptoms. sure, cracks in the pcv line will cause it to run a bit rich as all that post-MAF unmetered air is being seen in the 02 feedback, but at this point you're not getting any feedback anyway.
you can tune the FACTORY pcm to run without feedback from the o2's, it doesnt need them. (we used HP tuners). you dont need a standalone system.
you get **** gas mileage, but drivability is not sacrificed in the least. my car has been running for over a year with no o2 sensors and i have 0 issues with low speed or cruising driving.
while in his case, YES a lot of his problems are related to the fact he has no o2's, they are not REQUIRED if you tune them out of the system.
i do not recommend running without them if its a street car, but its not a NECESSITY.
11-02-2008, 02:36 AM
#14
Launching!
iTrader: (1)
Join Date: Oct 2007
Location: Germany
Posts: 277
Likes: 0
Received 0 Likes
on
0 Posts
Kamin....you may want to relook at your info. Sure an engine will run with gas, spark, and air...but you want it deliver the most power and efficiency you can get for free....by using o2 sensors! It's plain silly to not use o2 sensors on a fuel injected engine!
11-02-2008, 05:22 AM
#15
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
I guess all of you are right, since each one is talking about a very different situation and mentallity to what purpose he is using his car... Im using mine for racing (where im depending on less weight more than power) and as a daily driver also... but someone who probably takes the 02 off has another cheap alternative for daily driving since ur mileage will be shitty as Kamin said...
11-02-2008, 11:46 AM
#17
Why don't you scan your car and see what codes you have?
On a side-note, the only way temperature would have anything to do with drivability is if you overheated the engine and the ECU put you into 'SAFE MODE'.
On a side-note, the only way temperature would have anything to do with drivability is if you overheated the engine and the ECU put you into 'SAFE MODE'.
11-02-2008, 01:59 PM
#19
no, youre wrong.
you can tune the FACTORY pcm to run without feedback from the o2's, it doesnt need them. (we used HP tuners). you dont need a standalone system.
you get **** gas mileage, but drivability is not sacrificed in the least. my car has been running for over a year with no o2 sensors and i have 0 issues with low speed or cruising driving.
while in his case, YES a lot of his problems are related to the fact he has no o2's, they are not REQUIRED if you tune them out of the system.
i do not recommend running without them if its a street car, but its not a NECESSITY.
you can tune the FACTORY pcm to run without feedback from the o2's, it doesnt need them. (we used HP tuners). you dont need a standalone system.
you get **** gas mileage, but drivability is not sacrificed in the least. my car has been running for over a year with no o2 sensors and i have 0 issues with low speed or cruising driving.
while in his case, YES a lot of his problems are related to the fact he has no o2's, they are not REQUIRED if you tune them out of the system.
i do not recommend running without them if its a street car, but its not a NECESSITY.
this is not a tune. this is a ghetto make it work, or suitable for a racecar. if you take a car that's tuned in such a manner say to an elevation or a dramatic change in temperature, anything that would affect the air charge, the car is going to run even shittier because it's working off preset tables with no adaptive strategies.
that's not tuned, that's a car stuck in limp mode.
11-02-2008, 08:15 PM
#20
TECH Regular
Thread Starter
iTrader: (1)
Join Date: Oct 2007
Posts: 415
Likes: 0
Received 0 Likes
on
0 Posts
I kinda agree that 02's are actually needed... I don't agree so much with the different climate change though cause thats the job of the MAF sensor... anyhow, my opinion is that I should buy the 02's and I'm going to soon...