Adjustable MAF for C4?
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Cruising
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Adjustable MAF for C4?
I know someone who has a pretty built 84 (large cam, head work, headers, etc etc). The car runs great until he comes up to a stop light. It will throw a code (related to the MAF) and then the car will shut off. He was told that he needs to get an adjustable MAF.
Any of you know if this is true? If so, where can one be found?
EDIT - he has a 1986 setup.
Any of you know if this is true? If so, where can one be found?
EDIT - he has a 1986 setup.
Last edited by CorvettePD; Sep 17, 2006 at 05:22 PM.
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Adjustable MAF? for what reason? They are junk.
He needs to go through his wiring and figure out the problem if he's converted an 84 to use a MAF sensor.
He needs to go through his wiring and figure out the problem if he's converted an 84 to use a MAF sensor.
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Originally Posted by vader86
Adjustable MAF? for what reason? They are junk.
He needs to go through his wiring and figure out the problem if he's converted an 84 to use a MAF sensor.
He needs to go through his wiring and figure out the problem if he's converted an 84 to use a MAF sensor.
What can he expect from tracing wiring? I'm not familiar enough with his car to help trace the problem, but he's been told that the MAF he has will simply not read airflow correctly because of the amount he is now flowing. The several others he has spoke with have been suggesting the adjustable MAF.
Any other suggestions would be greatly appreciated.
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Originally Posted by Carpenter
Sounds more likely an IAC or vacuum problem?
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If he has a MAF on a TPI motor, all he really needs to do is have his chip properly done if he believes it cant read his airflow properly. If he has a code fault and the MAF otherwise works, then either he's got something crossed up with wiring, or the car has the wrong ECM tune.
Many people put down insane numbers using the basic stock MAF sensor, and beyond a certain point you just have to program things in correctly.
I dont feel like that is the issue he's having though. Its something besides the MAF.
Many people put down insane numbers using the basic stock MAF sensor, and beyond a certain point you just have to program things in correctly.
I dont feel like that is the issue he's having though. Its something besides the MAF.
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From: The Top of Utah
Originally Posted by CorvettePD
He must have a newer setup, I do know it has the TPI engine.
What can he expect from tracing wiring? I'm not familiar enough with his car to help trace the problem, but he's been told that the MAF he has will simply not read airflow correctly because of the amount he is now flowing. The several others he has spoke with have been suggesting the adjustable MAF.
Any other suggestions would be greatly appreciated.
What can he expect from tracing wiring? I'm not familiar enough with his car to help trace the problem, but he's been told that the MAF he has will simply not read airflow correctly because of the amount he is now flowing. The several others he has spoke with have been suggesting the adjustable MAF.
Any other suggestions would be greatly appreciated.
I think the wire tracing was to check the MAP to MAF conversion, that an '84 with a MAF has to have. I am not familiar with an adjustable MAF or what it can or will do (there IS such a thing?). It just sounds like this car just needs a properly tuned chip.
RACE ON!!!
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Originally Posted by vader86
If he has a MAF on a TPI motor, all he really needs to do is have his chip properly done if he believes it cant read his airflow properly. If he has a code fault and the MAF otherwise works, then either he's got something crossed up with wiring, or the car has the wrong ECM tune.
Many people put down insane numbers using the basic stock MAF sensor, and beyond a certain point you just have to program things in correctly.
I dont feel like that is the issue he's having though. Its something besides the MAF.
Many people put down insane numbers using the basic stock MAF sensor, and beyond a certain point you just have to program things in correctly.
I dont feel like that is the issue he's having though. Its something besides the MAF.
Okay, I just got off the phone with him, he has a 1986 setup.
Otherwise, sounds good.
Who do you suggest for tuning these? I know he had it previously tuned (he had to send it in) from someone by the name of Weber. He mentioned that the tune was apparently supposed to address this issue. Weber since suggested a new MAF.
In regards to the amount of power you say these can put down...at what point does the stock MAF become an issue?
He also says that there is currently a Bosch MAF in it.
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Oh, while we are on the subject of tuning, I imagine a dyno tune is the absolute best way to dial in, especially considering the mods he has done.
Know of any dyno tuners in the new mexico/west texas/arizona area that is familiar with these cars?
Know of any dyno tuners in the new mexico/west texas/arizona area that is familiar with these cars?
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From: The Top of Utah
Originally Posted by CorvettePD
I know someone who has a pretty built 84 (large cam, head work, headers, etc etc). It will throw a code (related to the MAF) and then the car will shut off.
Originally Posted by CorvettePD
He must have a newer setup, I do know it has the TPI engine.
Originally Posted by CorvettePD
Okay, I just got off the phone with him, he has a 1986 setup.
RACE ON!!!
Last edited by CFI-EFI; Sep 17, 2006 at 05:54 PM.
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Cruising
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Originally Posted by RRT vette
To clear things up...he has a 84 corvette converted to a TPI from a 86 corvette, correct?
He has an actual 1986, not an 84.
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O.K. now we can start. He needs a FSM to troubleshoot the code he has. He doesn't need an adjustable MAF, just figure out what is causing the ECM to throw the code. Could be the MAF, burn off relay, power relay, wiring circuit, connection, or ECM. Have him read what the code is and let us now.
http://www.yjshadow.com/ALDL_codes.htm
Codes on this page may differ from the 86 vette.
http://www.yjshadow.com/ALDL_codes.htm
Codes on this page may differ from the 86 vette.
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Originally Posted by CorvettePD
In regards to the amount of power you say these can put down...at what point does the stock MAF become an issue?
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Cruising
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Originally Posted by RRT vette
O.K. now we can start. He needs a FSM to troubleshoot the code he has. He doesn't need an adjustable MAF, just figure out what is causing the ECM to throw the code. Could be the MAF, burn off relay, power relay, wiring circuit, connection, or ECM. Have him read what the code is and let us now.
http://www.yjshadow.com/ALDL_codes.htm
Codes on this page may differ from the 86 vette.
http://www.yjshadow.com/ALDL_codes.htm
Codes on this page may differ from the 86 vette.
I do know he has looked up the code before and it said something about the MAF. I asked him to run the diagnostic mode again when he gets home and let me know what he gets exactly.
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Cruising
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Okay, he is getting code 34. He ran it again tonight and got a code 12.
Code 34 - Mass Air Flow (MAF) Sensor (Signal Voltage Low)
As far as a code 12, I can't find it in this shop manual. Perhaps he recorded the code incorrectly.
Code 34 - Mass Air Flow (MAF) Sensor (Signal Voltage Low)
As far as a code 12, I can't find it in this shop manual. Perhaps he recorded the code incorrectly.