Poor Cold Performance/Sag/Surge - Engine Controller (18-12-91)

WARNING: This page is about the Monaco ES, which is a different variant/trim than selected.

Publication date: 1991-09-09
Reference number: 18-12-91

POOR COLD PERFORMANCE/SAG/SURGE - ENGINE CONTROLLER

TECHNICAL SERVICE BULLETIN

Reference Number(s): 18-12-91, Date of Issue: September 9, 1991

COLD ENGINE POOR PERFORMANCE/SAG OR SURGE ON ACCELERATION

Model(s): 1991-92 (BB) Monaco Equipped with Single Board Engine

Controller (SBEC II)

Group: Engine Performance

Bulletin No. 18-12-91

Date: September 9, 1991

Symptom: Cold Engine Poor Performance/Sag Or Surge On Acceleration

SERVICE INFORMATION

1991 vehicles built after MDH 10-08-XX are equipped with a SBEC II.

These vehicles can be identified by an eight in the twelfth position of the VIN.

SYMPTOM/CONDITION

The vehicle will exhibit the two following conditions. First, the engine will sag and/or pop back during the first aggressive throttle tip in. This will happen within the first ten seconds of a cold engine start up when the ambient temperature is between approximately 60°F - 90°F (15°C - 32°C). Second, with the engine fully warm, the vehicle will exhibit a surge while traveling 30-40 MPH (50-65 KM/H).

DIAGNOSIS

Verify that the system is functioning as designed using the appropriate diagnostic test procedure.

PARTS INFORMATION

QTY.	PART NAME	PART NUMBER
1	Engine Controller	4605101
1	Authorized Modification Label	4275086

REPAIR PROCEDURE

This procedure involves replacement of the engine controller (SBEC) with a revised engine controller.

Following the service information, replace the original engine controller with the revised engine controller (4605101).
Type an authorized modification label, PN 4275086 as shown in Figure 1 and attach near the VECI label.

Fig 1: Authorized Modification Label