Wide sparkplug gaps can give hesitation and lead to spurious MAP sensor codes. Many Fiats suffer from wiring problems, water in loom and rotted looms.
Incorrect CAS clearance or variation between neighbouring teeth is greater than 0.2mm.
A perished diaphragm is a common fault in most turbo charged engines that utilise a by-pass valve. When the by-pass is faulty it can cause engine stalling at idle.
Some vehicles after 1993 may be equipped with an inertia switch that is located under the driver's seat. If the seat is moved forcibly during adjustment for position, the inertia switch could be actuated and the engine will subsequently fail to start.
Refer to the base idle setting procedures.
If the ground wires are too taut they will eventually break. If this so, check the position of the ground wire eyelets. Reposition the eyelets as necessary or solder extension cables onto the ground wires to avoid the problem of the wires breaking in service.
The EGR modulating valve is noisy and poor engine output when cold.
Ensure that the modulator vacuum hose is connected to the white vacuum connection on the throttle body. The blue vacuum connection on the throttle body should be capped. A modified EGR modulating valve was fitted from Tipo chassis number 4792410.
Tipo 1.8 with cat, ECM 4F4U7.P8PLD-EM, 7751798. A modified EPROM is available as a spare part. A modified ECM was fitted from June 1993.
It has been reported that there is a software issue with some Stilo models; the MIL is illuminating and displaying a fault code for the MAP sensor but the fault is with the software, not the sensor. The fault can only be cleared with a software download from a dealer.
