Q: My car sputter and dies, after replacing intake gaskets.

asked by on September 15, 2017

On my mustang it worked fine. But I had a engine light on for intake manifold gaskets. Anyways I bought new gaskets and it came with fuel injector o-rings. I properly cleaned the intakes off good enough to eat off of it. I hooked everything back where I got it after replacing gaskets. But when I was done I went to start it and it now sputter and dies. Right as I start it. If I rev it up it'll stay on until I release. I don't know why it would by a aci or maf because the car worked perfectly before I took it apart. I even took it apart again to make sure it was clean and all connected right. Now I just wanna go crazy.

My car has 189000 miles.
My car has an automatic transmission.

It sounds like the idle air control valve or the mass air flow sensor may not be properly reading the air intake volume, resulting in the stalling as you describe. This may also suggest there may be a bit of a vacuum leak remaining resulting in the incorrect readings. You may need to perform an idle relearn process to allow the IAC valve to adjust. Try doing the following: 1. Remove battery power for one (1) minute. Restore battery power and place air conditioning controls (if equipped) in the "off" position. 2. Firmly apply the parking brake and block the drive wheels. Start the engine, shift the transmission to drive for automatics and neutral for manuals. 3. Allow the engine to run until the engine cooling fan has cycled once, or a maximum of 10 minutes. 4. Turn the ignition key to the "off" position for at least 5 seconds. 5. Repeat Step 2. 6. Allow the engine to run for at least five (5) minutes. If you need further help with this, please reach out to us here at YourMechanic as we are always here to help.

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