2009 Silverado 5.3l rough idle

[Ashtonross]

Please help I recently purchased this truck after my last was totaled the truck has been airbagged an has some wiring messed with. it ran perfect for two weeks an then randomly started idling really rough wanting to die out. I’ve replaced the fuel pump, spark plugs, starter, positive and negative wires from battery, new MAP sensor an the oil pressure sensor it’s throwing po106 po507 po573 po2119 but when I clear them the truck won’t start unless I spray starting fluid. It gets enough fuel pressure an I’m checking for vacuum leak tmr anyone have anything to add? It would be much appreciated

 

[mrrsm]

When you fired your "Forum Shotgun" at this unfortunate problem at the Internet... it looks like you got a reply from another place that might be helpful:

 

[Mooseman]

Put the parts shotgun away. Lets look at this code by code:

P0106 - MAP/Barometric Pressure Circuit Range/Performance Problem
Since you replaced the MAP sensor, you have to check to see what the the readings are like. Sensor might be fine, could be a problem with the vacuum itself. Could be related to the throttle body codes.

P0507 Idle Air Control System RPM Higher Than Expected
P2119 Throttle Actuator Control Throttle Body Range
Both of these could be the cause of your problems. If the throttle body is not working correctly, like it's staying jammed open, it would cause a lower vacuum giving the P0106, cause a higher than normal idle and say it's not in range.


P0573 Cruise Control/Brake Switch A Circuit High
Unrelated to your problem. Probably just needs a new brake switch

Without a way to check live data using an advanced scanner or Torque Pro, I'd try replacing the throttle body with a used one from a pick-a-part yard. Give it a shake test to be sure there aren't any broken bits inside and it moves smoothly gently by hand before leaving the yard. Clean it before installing it. If your codes are resolved but the idle is still a little rough, it may need to have the idle relearned using an advanced scanner.

 

[Ashtonross]

Put the parts shotgun away. Lets look at this code by code:

P0106 - MAP/Barometric Pressure Circuit Range/Performance Problem
Since you replaced the MAP sensor, you have to check to see what the the readings are like. Sensor might be fine, could be a problem with the vacuum itself. Could be related to the throttle body codes.

P0507 Idle Air Control System RPM Higher Than Expected
P2119 Throttle Actuator Control Throttle Body Range
Both of these could be the cause of your problems. If the throttle body is not working correctly, like it's staying jammed open, it would cause a lower vacuum giving the P0106, cause a higher than normal idle and say it's not in range.


P0573 Cruise Control/Brake Switch A Circuit High
Unrelated to your problem. Probably just needs a new brake switch

Without a way to check live data using an advanced scanner or Torque Pro, I'd try replacing the throttle body with a used one from a pick-a-part yard. Give it a shake test to be sure there aren't any broken bits inside and it moves smoothly gently by hand before leaving the yard. Clean it before installing it. If your codes are resolved but the idle is still a little rough, it may need to have the idle relearned using an advanced scanner.

I’m also leaning towards a faulty throttle body because sometimes it’s starts sometimes it won’t an sometimes it’s idles just fine an then it just randomly starts acting up again but for the past day it won’t start or idle without starting fluid

 

[Ashtonross]

I’m also leaning towards a faulty throttle body because sometimes it’s starts sometimes it won’t an sometimes it’s idles just fine an then it just randomly starts acting up again but for the past day it won’t start or idle without starting fluid

I have a snap on d10 reader I’m just not sure how to use it I can check an clear codes that’s all I’ve fiqured out so far

 

[Mooseman]

There should be a menu of special functions for the idle relearn. For the live data, look for desired/requested throttle % and actual throttle %. If the two don't match, either it's the throttle body or the pedal sensor. The pedal you can confirm by just pushing on it and seeing that it's reacting as desired but if the throttle isn't, then that's your problem child.

This one talks about it. Maybe all you need is the relearn.

 

[Ashtonross]

I was just out there messing with the throttle body it wouldn’t open but a 1/4 of a inch when I push in the gas I sprayed it with wd/40 an it started opening all the way. Before I realized this it was running good for about 10 min I gave it some gas an it ran up to 3k rpm an stayed there so I turned it off an that’s when I started inspecting the throttle body

 

[Ashtonross]

There should be a menu of special functions for the idle relearn. For the live data, look for desired/requested throttle % and actual throttle %. If the two don't match, either it's the throttle body or the pedal sensor. The pedal you can confirm by just pushing on it and seeing that it's reacting as desired but if the throttle isn't, then that's your problem child.

This one talks about it. Maybe all you need is the relearn.

 

[Ashtonross]

View attachment 102727

 

[Ashtonross]

There should be a menu of special functions for the idle relearn. For the live data, look for desired/requested throttle % and actual throttle %. If the two don't match, either it's the throttle body or the pedal sensor. The pedal you can confirm by just pushing on it and seeing that it's reacting as desired but if the throttle isn't, then that's your problem child.

This one talks about it. Maybe all you need is the relearn.

Just cleared all the codes an did a idle relearn it still didn’t want to start. I used starting fluid it cranked right up an is idling just fine as of right now

 

[Mooseman]

I think your throttle body is either really caked up or needs replacing. Did any of the codes come back? They could be pending instead of hard set.

 

[Ashtonross]

I think your throttle body is either really caked up or needs replacing. Did any of the codes come back? They could be pending instead of hard set.

Ya po106 and po2119 popped back in after I turned the truck off an it wouldn’t start again