Possible solution for occasional idle stumble

Hi there,

my '90 V12 with Marelli had that occasional idle stumble several times reported by other owners in this forum. After looking at the common culprits (CPS, white cable etc.) I finally found the solution for my car: The TPS connector on the harness side, usually buried somewhere down the firewall, showed cracked insulation immediately where the wires exit the molded connector. I separated all wire strains and made sure that there is ample clearance between the wires. Since then, the car is running very well without any more stumble. I suppose some bare wire strains occasionally connected to each other causing electric shorts to the Fuel injection ECU. I obviously need a more permanent fix as water on the bare wires can cause continued trouble.
Perhaps that helps some owners.


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