high idle on startup then gets rough once warm
12-19-20, 11:26 PM
#1
Junior Member
Thread Starter
high idle on startup then gets rough once warm
Hi all,
I have done some researching, testing, and I've come to a point where I am stuck.
My car is idling much higher than it has before. Once warmed up, the idle drops to ~500rpm and becomes rough, almost as if it's seeking for more air to stabilize.
I pressure tested the system looking for boost leaks and found none apparent. I then also sprayed the injectors with soapy water and no change - so I think those seals are tight.
The only change I've made is the spark plugs, I went 2 steps warmer, and I'm on my second set in the past 4 months.
My car has run terribly rich since I've had it. Like idles at 11 rich. I was hoping to get a Haltech in to replace the Apexi to control and have visibility into the variables, and get a proper tune.
This is also a single turbo build.
Should I pull the injectors and flow test them? Should I do a compression test? Someone mentioned a pinched side seal but I'm not sure, this motor has about 1200 miles since the rebuild.
I'd love to talk about this more to brainstorm. Happy to provide more details.
Thank you!
I have done some researching, testing, and I've come to a point where I am stuck.
My car is idling much higher than it has before. Once warmed up, the idle drops to ~500rpm and becomes rough, almost as if it's seeking for more air to stabilize.
I pressure tested the system looking for boost leaks and found none apparent. I then also sprayed the injectors with soapy water and no change - so I think those seals are tight.
The only change I've made is the spark plugs, I went 2 steps warmer, and I'm on my second set in the past 4 months.
My car has run terribly rich since I've had it. Like idles at 11 rich. I was hoping to get a Haltech in to replace the Apexi to control and have visibility into the variables, and get a proper tune.
This is also a single turbo build.
Should I pull the injectors and flow test them? Should I do a compression test? Someone mentioned a pinched side seal but I'm not sure, this motor has about 1200 miles since the rebuild.
I'd love to talk about this more to brainstorm. Happy to provide more details.
Thank you!
12-20-20, 08:11 AM
#2
So high idle on start-up and then it hunts, or lopes up and down when it warms up.
I would check for a vacuum leak after the TB somewhere. Vacuum hoses, or worse case scenario the upper to lower intake manifold gasket. A search in the tech section using terms like “hunting idle” and/or “vacuum leak” might be helpful.
I would check for a vacuum leak after the TB somewhere. Vacuum hoses, or worse case scenario the upper to lower intake manifold gasket. A search in the tech section using terms like “hunting idle” and/or “vacuum leak” might be helpful.
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