car wont rev past 1500 rpm
03-22-2010, 12:16 AM
#1
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car wont rev past 1500 rpm ok for those of you who helped me with the vacuum leak problem and especially those who told me the iac should extend and retract upon turning the key on then off i thank you. turned out i had a bad pcm. i also had a bad maf but never threw a code. however now i have the problem that it idles fine but wont let me rev past 1500 rpm. i havent checked codes again yet but as soon as i do i wil post my findings. its like the ecu wont let it rev any higher. not like it cuts out or anything it just straight up dont go past 1500 rpms like some kind of protect mode. anyone have this problem or know a solution
03-23-2010, 11:51 AM
#7
ok for those of you who helped me with the vacuum leak problem and especially those who told me the iac should extend and retract upon turning the key on then off i thank you. turned out i had a bad pcm. i also had a bad maf but never threw a code. however now i have the problem that it idles fine but wont let me rev past 1500 rpm. i havent checked codes again yet but as soon as i do i wil post my findings. its like the ecu wont let it rev any higher. not like it cuts out or anything it just straight up dont go past 1500 rpms like some kind of protect mode. anyone have this problem or know a solution
Any more details on your setup (motor mods, trans being used, what tune you're running?)
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03-23-2010, 07:13 PM
#8
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Yea that's what I'm thinking cause it's not like it's runnng rough after 1400 or 1500 it's just straight up says no when u try to go any farther. The tune was done by chevy thunder who also made the harness. So does anyone know how to get it out of this so called abuse mode?
03-23-2010, 07:48 PM
#9
I found this searching on the EFILive forum
http://forum.efilive.com/showthread....2abuse+mode%22
So I'm going to try both grounding those pins or changing the parameters for entering abuse mode and see what happens.
I just completed the 0411 PCM swap on my 97 model Vortec 7.4. This engine is in an 89 suburban using a standalone wiring harness, from Painless. I have loaded the calibrations for the 2001 Express Van. The OS running is 12212156. I do not have a VSS hooked up since the 89 suburban didn't have one. I am using a 4spd (SM465) transmission.
Here's the issue: cranks and idles fine, but if I try to rev it up when it gets to a little under 2000 RPM it tries to die. I am wondering if the abuse management parameters are making it do this? If I ground pins 32&34 on the blue connector as if I were going to do a crank relearn, then it doesn't do this at all. Maybe the abuse management is kicking in because I don't have VSS hooked up, manual trans, and no park neutral or clutch signals?
Here's the issue: cranks and idles fine, but if I try to rev it up when it gets to a little under 2000 RPM it tries to die. I am wondering if the abuse management parameters are making it do this? If I ground pins 32&34 on the blue connector as if I were going to do a crank relearn, then it doesn't do this at all. Maybe the abuse management is kicking in because I don't have VSS hooked up, manual trans, and no park neutral or clutch signals?
So I'm going to try both grounding those pins or changing the parameters for entering abuse mode and see what happens.
