Fuel Delivery and Air Induction: Application and ID

NOTE: These vehicles were available with two different fuel, ignition, and emission systems in 1991. The systems can be distinguished from each other by; - Shape and position of the ignition coil, air cleaner, and relay box, along with several other component differences in the engine compartment.

Visible Differences:
A "relay cluster" on early model vehicles versus a "power distribution" center on late model vehicles.
EARLY '91

Relay Location/Identification:

LATE '91

Power Distribution Center (PDC) And Diagnostic Connector:

A Solid State Ignition (SSI) on early model vehicles versus a Direct Ignition System (DIS) on late model vehicles.
EARLY '91

Relay Location/Identification:

LATE '91

Ignition Coil-Pack:

An Idle Speed Regulator (ISR) on early model vehicles versus an Automatic Idle Speed (AIS) motor on late model vehicles.
EARLY '91

Throttle Position Sensor And Idle Speed Regulator:

LATE '91

Throttle Position Sensor (TPS)/Automatic Idle Speed (AIS) Motor:

EARLY '91

Engine VIN Code [1] U
Engine Displacement 3.0L (182 cu. in.)
Engine Configuration V6
Fuel System Multi Point Fuel Injection (MPFI)
Ignition System Solid State Ignition (SSI)
Computer System Electronic Control Unit (ECU)

LATE '91

Engine VIN Code [1] U
Engine Displacement 3.0L (181 cu. in.)
Engine Configuration V6
Fuel System Multi Point Fuel Injection (MPFI)
Ignition System Direct Ignition System (DIS)
Computer System Single Board Engine Controller (SBEC-II)


Remarks:
[1] The eighth digit of the VIN denotes engine code.