Engine Control - New ECM, Cold Driveability/Startability

90toyota05 REFERENCE ENGINE
NUMBER 024
DATE 08-31-90
MODEL MX8 MA7 '86-'90
TITLE 7M-G(T)E ECU / COLD START INJECTOR TIME SWITCH MODIFICATION

This bulletin contains additional information to TSB Volume 10, Engine # 010 previously issued 09-01-89.

The modified cold start thermal time switch listed in Engine TSB # 010 is still available for 1986-1989 Supras and Cressidas equipped with 7M series engines to improve startability only.

A modified TCCS ECU is now available for 1989-1990 Supras and Cressidas which improves both cold driveability and startability.



The proper repair for these conditions should be determined by the customer complaint as listed below:
NOTE: 1989 model Cressidas and Supras have both repairs available. If the only complaint is hard starting, the Thermal Time Switch should be replaced. If there is a cold driveability complaint, you must install the new ECU.
CAUTION: The new TCCS ECU should not be used with the new 45~C Thermal Time Switch. This ECU has improved cold start injector control logic and is designed to work with the original 22~C time switch only.



The illustration below shows how to identify the temperature range of a cold start injector time switch.



PART NUMBER INFORMATION:
PRODUCTION EFFECTIVE:

The new (45~C) cold start injector time switches are available for field repair parts only.



Production change information for the modified TCCS ECU is as follows:
SERVICING INFORMATION:

Before replacing an ECU or a cold start injector time switch, perform a thorough inspection to verify that all engine mechanical, fuel and electrical/electronic systems are to recommended specifications.

PARTS RETURN INFORMATION:

The replacement ECU's are remanufactured by Nippondenso-Los Angeles (NDLA). In order to maintain cores for rebuilt units, the original ECU must be sent to NDLA as soon as it has been replaced.

Note: Please complete the core information and core credit forms which are enclosed with the remanufactured ECU.

Return Cores to: Toyota Motor Distributors C/0 Nippondenso-Los Angeles 3900 Via Oro Avenue Long Beach, CA 90810