Throwing Codes.....
Thread Starter
Launching!
Joined: Jun 2002
Posts: 221
Likes: 0
From: Orlando, FL
Throwing Codes..... Alright... here's the story...
Installed a 232/236 cam... peaked at 6600... I decided to advance it 2* to lower the powerband... well... pistson hit valves... valves bent... ya know how it goes.
I got a set of cleaned up stock heads. Put them on... car has been doing alright.
A week after I put the cam in (before piston mashing), it started throwing the P0121 and idling like crap. I got it tuned, and it went away until I got stupid and played with crap.
Fast forward to post piston mashing....
Its now throwing P0121 every few days... and now it has recently throwin a P0121, P0172 and P0175. OCCASIONALLY after a warm start, the car would act like it was heavily missing. It would have absolutely no power at all, and as I gave it more throttle... it would go away and power would pick back up. The codes stayed away for about 2 weeks once... but now its back.
Any ideas on this one????
Installed a 232/236 cam... peaked at 6600... I decided to advance it 2* to lower the powerband... well... pistson hit valves... valves bent... ya know how it goes.
I got a set of cleaned up stock heads. Put them on... car has been doing alright.
A week after I put the cam in (before piston mashing), it started throwing the P0121 and idling like crap. I got it tuned, and it went away until I got stupid and played with crap.
Fast forward to post piston mashing....
Its now throwing P0121 every few days... and now it has recently throwin a P0121, P0172 and P0175. OCCASIONALLY after a warm start, the car would act like it was heavily missing. It would have absolutely no power at all, and as I gave it more throttle... it would go away and power would pick back up. The codes stayed away for about 2 weeks once... but now its back.
Any ideas on this one????
TECH Enthusiast
Joined: Oct 2003
Posts: 729
Likes: 0
From: Bakersfield, Ca.
Re: Throwing Codes..... Open this pdf file and go to page 52.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
Thread Starter
Launching!
Joined: Jun 2002
Posts: 221
Likes: 0
From: Orlando, FL
Re: Throwing Codes.....
Open this pdf file and go to page 52.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
I'll hope it sets again and use my friends tech 2 to take a look at freeze frame data. Can you see freeze frame info with ATap?
TECH Enthusiast
Joined: Oct 2003
Posts: 729
Likes: 0
From: Bakersfield, Ca.
Re: Throwing Codes.....
Open this pdf file and go to page 52.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
http://carprogrammer.com/Z28/PCM/LS1/Holden_LS1.pdf
I would find out what was out of whack when the code froze, and work from there.
Good luck,
Paul.
I'll hope it sets again and use my friends tech 2 to take a look at freeze frame data. Can you see freeze frame info with ATap?
With EFILiveV5/ATAP you can, not sure with other versions.
They should stay set and have the freeze data there if you have not reset them yet.
Paul
Thread Starter
Launching!
Joined: Jun 2002
Posts: 221
Likes: 0
From: Orlando, FL
Re: Throwing Codes.....
With EFILiveV5/ATAP you can, not sure with other versions.
They should stay set and have the freeze data there if you have not reset them yet.
Paul
They should stay set and have the freeze data there if you have not reset them yet.
Paul
Thread Starter
Launching!
Joined: Jun 2002
Posts: 221
Likes: 0
From: Orlando, FL
Re: Throwing Codes..... Well... I got some autotap data on it tonight.
Read the freeze frame out of the PCM, and it does it when the PCM is requesting 1% throttle, and it sits at 0%.
Conditions for DTC P0121
No MAP or TP Sensor DTC's set: True
Engine Run Time Greater than 10 Seconds: True
Engine Coolant Temperature Greater than 0C: 200F (whatever that is in C)
IAC Between 0 and 255: Couldnt find it. But it probably was.
MAP is less than 55kPa: False
MAP is more than 65kPa: True - 69kPa
MAP is steady: I guess it was. At idle it would stick around the same area.
Predicted Throttle Angle: 1%
Actual Throttle Angle: 0%
Apparantly it throws the code at idle. KMH was showing 0. RPM was at 950. That tells me idle, as well as the actual throttle angle.
Did some driving around... one time... the sensor would barely go above 1 volt. Turned it off, started it back up, it started getting correct voltages again.
Anyone have any ideas???
Read the freeze frame out of the PCM, and it does it when the PCM is requesting 1% throttle, and it sits at 0%.
Conditions for DTC P0121
No MAP or TP Sensor DTC's set: True
Engine Run Time Greater than 10 Seconds: True
Engine Coolant Temperature Greater than 0C: 200F (whatever that is in C)
IAC Between 0 and 255: Couldnt find it. But it probably was.
MAP is less than 55kPa: False
MAP is more than 65kPa: True - 69kPa
MAP is steady: I guess it was. At idle it would stick around the same area.
Predicted Throttle Angle: 1%
Actual Throttle Angle: 0%
Apparantly it throws the code at idle. KMH was showing 0. RPM was at 950. That tells me idle, as well as the actual throttle angle.
Did some driving around... one time... the sensor would barely go above 1 volt. Turned it off, started it back up, it started getting correct voltages again.
Anyone have any ideas???
Thread Starter
Launching!
Joined: Jun 2002
Posts: 221
Likes: 0
From: Orlando, FL
Re: Throwing Codes..... Did a few WOT runs tonight... the SES light came back on, and the crappy idle returned. Im wonderin WTF is going on. Im getting a TPS from a friend tomorrow... hopefully that will take care of it.
Anyone who has monitored their TPS % or Voltage... what are they at with your foot off the gas????
Anyone who has monitored their TPS % or Voltage... what are they at with your foot off the gas????
Trending Topics
TECH Fanatic
Joined: Mar 2003
Posts: 1,839
Likes: 0
From: La Porte, TX
TTT guys I'm having this same problem, what should TPS voltage be at Idle. I have done a search and am getting many different answers. Some say .4 some .6 some .9 some 1.0??????????????? who is right? Does anyone know what "GM says" the TPS voltage at idle should be?
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