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I have changed the TPS Unit with a new one but the code still throws.
P0507 Can be an intake air leak. I looked for one using propane and no luck. I double checked all hoses and its a pretty tight vacuum at this time.
The only real problem I have atm is low rpm acceleration and a rough idle.
If I come to a full stop it is not uncommon for me to hesitate my way and lurch forward until I hit about 30 or give up and go wot. Sometimes WOT will pull me right out of it other times it will really act up. If I go to wot right from the line it never lurches... but the cops do not like that much.
I was looking at the IAC valve. I unplugged it and it seemed to run better overall So I pulled it and tested it, It was at 51 OHM from A to B and C to D. Which looks to be good. I cleaned it up with some MAF Sensor cleaner and put it back in.
I will drive it more tomorrow.
Has anyone had any luck fixing this combination of codes and can give me some guidance. I am new to the LS1 and.... am beginning to miss my old carb and distrib setup
Check the voltage coming from the TPS.
It needs to be below about .65V with the throttle closed and should go up to about 4.5V at WOT. I check the voltage via my scanner, but it can be done with a volt meter; I'm not sure of best way to "splice" in.
Searching P0507 on some other forums, one suggestion is to be sure your throttle blade is closing all the way and is not binding. If it binds, you will get a P0121 because the TPS voltage will be over .65V. The PCM will then zero out the IAT trying to get the idle speed down and that might give a P0507. Finally the Adaptive Idle system will lower the ignition advance to lower the idle speed and give you a rough idle.
Perhaps this is not your problem, but is something simple to check.
Check the voltage coming from the TPS.
It needs to be below about .65V with the throttle closed and should go up to about 4.5V at WOT. I check the voltage via my scanner, but it can be done with a volt meter; I'm not sure of best way to "splice" in.
Searching P0507 on some other forums, one suggestion is to be sure your throttle blade is closing all the way and is not binding. If it binds, you will get a P0121 because the TPS voltage will be over .65V. The PCM will then zero out the IAT trying to get the idle speed down and that might give a P0507. Finally the Adaptive Idle system will lower the ignition advance to lower the idle speed and give you a rough idle.
Perhaps this is not your problem, but is something simple to check.
That is some great advice to check. I will give it a look. I have used 2 TPS's that both throw this code. I just changed the pedal since what my original builder did would bind at 20% throttle. And never go to 0 fully. This almost killed me a few times. The code is still thrown tho so I will figure out a way to test the voltage.
I read a bad IAC can cause this... here is my new... IAC. Looks new to me. Could this be causing the Spark retard to adjust timing to lower the idle and causing both the P0507 and hesitant takeoffs I am having?
It is definitely trashed, this engine has less than 500 miles on it. It has been a horror story as I paid a guy to build me a new one and I have wired in the harness after repo'ing the vehicle, replaced all the accessories, oil pump, Replumped the fuel system and cooling systems and replaced nearly all the sensors, throttle body, and plug wires. At this point when I say here is my New *insert item* it's more of a joke and the only way I can laugh at it anymore. I am taking the builder to court to recover the costs he was paid in advance minus some parts.
This is the replacement but I am straight outta cash atm so I need to wait for a payday to do it.
Yikes, these have gone up to $115.
That seems double from a few years ago; perhaps they are no longer made and inventory is getting used up. I see one a ebay for $90 with free shipping from NH.
Google "BWD 31036" to shop around.
So I was watching my EFI system live as I drove. I noticed the spark retard or... Timing adjustment change from 10-35ish as I drove at idle it would go up to about 32-35 as the rpm would adjust. I have not had the money yet to change the IAC but I wonder if this is a good reason why since the IAC may not be controlling the air flow enough to change the RPM's so the system adjust the timing instead. When I accelerate with the forward timing and under load I hesitate and chug until the system can put me back to the right timing?
I am shooting in the dark here as I am new to this whole... Computer runs it type thing. So thoughts would be appreciated.
Would a proper IAC have enough control over the rpm to stop it from changing the timing so much to keep idle correct? Or is this more in the realm of I should call my tuner back out?
Well I replaced the IAC this weekend and while I could definitely tell a difference in the idle feel, it still hesitates on occasion. Noticeably less. I still think it is overtimed.
11-19-2016, 11:16 PM
P0507 and P0121 
