Check the ISCV action. If ISCV operation is poor, clean the ISCV with white spirit. Check the throttle housing and throttle valve for oil and carbon deposits.
Note: A modification to improve airflow was introduced in order to combat excessive oil and carbon deposits. The modification is available as a service upgrade and was fitted in production from 1990.
Ensure that the ISCV securing screws have not been over tightened.
On very early vehicles, the CO may be reset to between 1.2 and 1.5% CO with the aid of a suitable FCR. In later models the CO is not adjustable.
Ascertain the colour of the ISCV connector. If the ISCV connector is green, fit a modified harness as described in ‘ISCV Seizing’.
The following modification is available to early engines with the green ISCV connector. All later vehicles with a black ISCV connector have been modified during production.
Ascertain the colour of the ISCV connector. Continue only if the ISCV connector is green. Fit a modified ISCV harness (part number 96132512) between the ISCV and the multi-plug connector. The modified ISCV harness contains a diode.
A common fault that affects most Fiat vehicles is water in the wiring loom leading to corroded connectors and rotted wiring looms.
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 0.2 mm.
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.
Failure of the CTS.
Wide sparkplug gaps can give hesitation and lead to spurious MAP sensor codes.
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 an engine stalling at idle situation.
