Type IV EFI Field Guide

Electrical Checking/Testing

System Check With Volt/Ohmmeter

The entire A.F.C. System can be checked electrically at the control unit plug using an ohmmeter or volt meter according to the following chart.

Use this handy form to track your results.

OHMMETER TO TERMINAL

SPECIFICATIONS

CHECKS

1 and Ground

Disconnect white injection wire at coil ohms: hook wire to ground 0 ohms.

Wire to #1 terminal on coil.

3 and 18

Press accelerator pedal down fully. 0 ohms

Full throttle enrichment circuit thru throttle switch.

5 and Ground

0 ohms

Ground Circuit

6 and 9

200-400 ohms

Air Sensor Circuit

6 and 8

130-260 ohms

Air Sensor Circuit

8 and 9

70-140 ohms

Air Sensor Circuit

6 and 7

40-300 ohms

Air Sensor Circuit

7 and 8

100-500 ohms

Air Sensor Circuit

6 and 27

Max. 2800 ohms at 68°F

Air Sensor Circuit

13 and Ground

2100-2900 ohms at 68°F 270-390 at 176°F

Head Sensor

14 and 10

Approx. 7 to 9 ohms

Injector wire and resistor

15 and 10

Approx. 7 to 9 ohms

Injector wire and resistor

32 and 10

Approx. 7 to 9 ohms

Injector wire and resistor

33 and 10

Approx. 7 to 9 ohms

Injector wire and resistor

16 and Ground

0 ohms

Ground Circuit

17 and Ground

0 ohms

Ground Circuit

34 at control unit and 37 on the double relay

Approx. 30 ohms

Auxiliary air regulator and wires.

VOLTMETER TO TERMINAL

SPECIFICATIONS

CHECKS

4 and Ground

Min. 9.5 volts during cranking 0 volts at all other times

Signal from starter

10 and Ground

12 volts with key ON
0 volts with key OFF

Voltage supply to computer

20 and Ground
(California uses 28 and ground)

12 volts with key ON and sensor flap open (or bridge terminal 36 to terminal 39 of air flow sensor plug)

Pump Circuit

control unit plug numbering

AFC Pinout