1.6L Diesel Engine Adjusting Modified Injection Pump (GROUP 23, NO. 85-01)

Publication date: 1970-01-01
Reference number: GROUP 23, NO. 85-01

1.6L DIESEL - INJECTION PUMP WITH IDLE SPEED BOOST

TECHNICAL SERVICE BULLETIN

Reference Number(s): GROUP 23, NO. 85-01, Date of Issue: November 8, 1985

DIESEL INJECTION SYSTEM INJECTION PUMP WITH IDLE SPEED BOOST

Model(s): 1986 Volkswagen Golf, Jetta 1.6L Diesel Engine and Turbo Diesel

Group: 23 - Diesel Direct Fuel Injection

Bulletin No.: 85-01

Part Identifier: N/A

Date: November 8, 1985

SERVICE INFORMATION

The diesel pump now uses a manually operated idle boost, allowing better control of emissions and reduced vibration during idle. When you pull the cold start cable to the first detent, the idle is raised to about 900 rpm. By pulling the cable out completely it increases to about 1050 rpm.

The modified pump shown in Fig 1 , includes the following changes:

Previous idle adjustment screw, sealed with tamper proof cap (cannot be turned).
Linkage with cap nut for idle speed adjustment.
Stop screw for minimum idle speed.
Stop screw for speed boost.
Tamper proof cap.

IDLE SPEED, CHECKING AND ADJUSTING

Requirements

Cold start cable must not be pulled out.
All electrical consumers turned off.
Minimum engine oil temperature 60°C (140°F).

- Measure rpm using VW 1367 ignition tester and/or adaptor VW 1324.

CAUTION: The idle adjusting procedure has been changed. The old idle adjusting screw is sealed with a tamper proof cap (See #5 in Fig 1 ) and can no longer be turned.

IDLE SPEED, ADJUSTING

- Measure idle speed.

Specification 850 +/- 30 rpm.

If No

- Turn linkage (2). See Fig 1 .

Turning cap nut clockwise increases rpm.
Turning cap nut counterclockwise decreases rpm.

IDLE SPEED BOOST, CHECKING

- Pull cold start cable out to first detent. Idle speed should increase to 910 +/- 30 rpm.

- Pull cold start cable all the way out. Idle speed should increase to 1050 +/- 50 rpm.

NOTE: The basic pump adjustment performed by the manufacturer, assures that normal idle and boost can be adjusted within the specifications. If however, you cannot adjust the idle or idle boost within the specifications; perform the following adjustment.

Idle Adjustments

If the idle speed cannot be adjusted below 900 rpm by turning the cap nut because it hits limiting screw (3):

- Loosen lock nut on low speed stop screw (3) and turn screw counterclockwise. See Fig 1 .

- Adjust idle speed on the cap nut to 850 rpm by turning the linkage.

- Turn stop screw in until it just touches low idle stop and tighten lock nut.

Idle Speed Boost

If idle speed varies from specification when cold start cable is pulled out completely:

Specification 1050 +/- 50 rpm.

- Loosen lock nut on stop screw (4) and, with cold start cable pulled out completely, adjust idle speed to specification by turning stop screw. See Fig 1 .

- Tighten lock nut on stop screw.

Fig 1: Modified Injection Pump