Start up/Idle issues
Thread Starter
Pro
Joined: Aug 2003
Posts: 573
Likes: 109
From: Louisville
Start up/Idle issues
For the last few weeks the car wouldn't turn over when cold on the 1st try but would always start the 2nd time. The tuner took out 2 degrees out of timing and added 15% cranking fuel. Now if the car sits and idles for a few minutes and you shut if off it smells like a lot of fuel and it won't start for 30-40 min. I'm at a loss for what this could be unless it's related to the timing.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,308
Likes: 3,924
From: Cape Coral, Florida
Have your tuner undo the changes he made to solve the fueling (flooding problem) he created. Then look into cleaning the IAC (idle air control valve) on the throttlebody. If it's gummed up/ sticking that could make the electric motor take longer to open and by the time you try to start the second time it's open enough to start the engine. The IAC valve when open bypasses the closed throttlebody butterfly when the engine is cold to get more air into the engine (kind of like a choke but in reverse) the engine adds more fuel and the engine starts.
Hope that helps.
Hope that helps.
Thread Starter
Pro
Joined: Aug 2003
Posts: 573
Likes: 109
From: Louisville
Have your tuner undo the changes he made to solve the fueling (flooding problem) he created. Then look into cleaning the IAC (idle air control valve) on the throttlebody. If it's gummed up/ sticking that could make the electric motor take longer to open and by the time you try to start the second time it's open enough to start the engine. The IAC valve when open bypasses the closed throttlebody butterfly when the engine is cold to get more air into the engine (kind of like a choke but in reverse) the engine adds more fuel and the engine starts.
Hope that helps.
Hope that helps.
Moderator, Tech Contributor
Joined: Sep 2013
Posts: 15,308
Likes: 3,924
From: Cape Coral, Florida
I’d put a fuel pressure gauge on the car and check pressure key on engine off and then how fast the pressure bleeds off…you’ll have to get underneath the rear of the car and see if there are any possible fuel leaks down there…also putting a scan tool on the car and looking at some live data…O2’s, fuel trims etc…if an upstream O2 sensor is “stuck” lean you will have a rich exhaust smell…happened to me ( bad O2 sensor) a few months ago but no trouble stating on the first try.
Thread Starter
Pro
Joined: Aug 2003
Posts: 573
Likes: 109
From: Louisville
I’d put a fuel pressure gauge on the car and check pressure key on engine off and then how fast the pressure bleeds off…you’ll have to get underneath the rear of the car and see if there are any possible fuel leaks down there…also putting a scan tool on the car and looking at some live data…O2’s, fuel trims etc…if an upstream O2 sensor is “stuck” lean you will have a rich exhaust smell…happened to me ( bad O2 sensor) a few months ago but no trouble stating on the first try.
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