engine takes off its own
03-19-2013, 05:12 PM
#1
On The Tree
Thread Starter
engine takes off on its own
hi Guys I just got done changing my transmission, and rear end. I pulled my intake off and cleaned it up and every time since then when i put my truck in drive it wants to take off without me even giving it any throttle???
also if im going down the road at any speed and put the truck in neutral (while rolling) the truck stays revved too 1800 rpm??? at idle in park I noticed it is idling 100-150 rpm high than it used too? could it be a Vacuum leak or something or a fuel injector o-ring (reused the old ones)
also if im going down the road at any speed and put the truck in neutral (while rolling) the truck stays revved too 1800 rpm??? at idle in park I noticed it is idling 100-150 rpm high than it used too? could it be a Vacuum leak or something or a fuel injector o-ring (reused the old ones)
Last edited by bbowerman; 03-19-2013 at 05:50 PM.
03-19-2013, 07:48 PM
#7
Not saying this could not happen but I have never heard of anyone having that issue. I wouldn't just randomly open it and close it all the time but I have opened mine to clean them before without issue. On that note we don't even know what year his truck is, that would help so we know if it has a IAC or not. Seeing as though the intake was just removed, obvious signs point to a vacuum leak based on the symptoms.
Trending Topics
03-19-2013, 09:06 PM
#8
Since you did not tell us what year you are working on, here are some possibilities.
If it is a drive by cable. The IAC is the sensitive part that you need to be careful with. Opening and closing the Throttle blade will have no effect on a cable operated set up.
If it's electronic you need to be careful not to force the blade open. Forcing it open can cause internal damage.
If you open an electronic throttle blade to clean it, you may need to have it re calibrated. It needs to relearn the volume of air and adjust the blade opening correctly. Usually you will get a check engine light.
As far as removing the intake goes, If you did not replace the gaskets you most likely have an intake leak.
The intake gaskets have been known not to hold a seal after being removed. They typically flatten out from the heat of the engine and the ethanol in the gas. GM redesigned them with a green material that is supposed to be more resistant to the ethanol. You can spray brake clean around the intake were it seat to the head and see if the Idle changes while it is running. This would indicate a leak. Some times the leak is on the bottom and is hard to detect. It only shows up when you smoke the intake
If it is a drive by cable. The IAC is the sensitive part that you need to be careful with. Opening and closing the Throttle blade will have no effect on a cable operated set up.
If it's electronic you need to be careful not to force the blade open. Forcing it open can cause internal damage.
If you open an electronic throttle blade to clean it, you may need to have it re calibrated. It needs to relearn the volume of air and adjust the blade opening correctly. Usually you will get a check engine light.
As far as removing the intake goes, If you did not replace the gaskets you most likely have an intake leak.
The intake gaskets have been known not to hold a seal after being removed. They typically flatten out from the heat of the engine and the ethanol in the gas. GM redesigned them with a green material that is supposed to be more resistant to the ethanol. You can spray brake clean around the intake were it seat to the head and see if the Idle changes while it is running. This would indicate a leak. Some times the leak is on the bottom and is hard to detect. It only shows up when you smoke the intake
03-19-2013, 10:50 PM
#9
On The Tree
Thread Starter
2001 5.3 drive by cable with IAC
I also noticed that my top end is weaker like at 85 when i stomp it... it used to move better but whatever it isis taking that top end away
I also noticed that my top end is weaker like at 85 when i stomp it... it used to move better but whatever it isis taking that top end away
03-19-2013, 10:59 PM
#10
Then make sure you have no vacuum leaks first. Then disconnect the battery on the negative side and let it sit for 30 minutes. Reconnect the battery and start the truck. Let it idle only for at least 10 minutes. This should allow it to relearn the correct values. other wise you need a factory type scan tool.