For 1990-2009 cars

# DRIVEABILITY SUMMARY WARM AMBIENTS

DRIVEABILITY SUMMARY - WARM AMBIENTS

#### VEHICLES AFFECTED: 1982-87 PASSENGER CARS WITH 5.0L LG4 ------------------ (VIN CODE H) ENGINE OR 5.0L L69 (VIN CODE G) ENGINE WITH 3C CARBURETORS

Some vehicles may exhibit driveability symptoms related to the combination of high ambients, hot soaks and relatively high Reed Vapour Pressure fuels.

Several bulletins have been issued on this topic and this bulletin is intended as a convenient easy to use summary. As usual, normal service procedures should be utilized to assure that the vehicle is set to specifications before proceeding to use the service procedures recommended in this bulletin.

#### WARM AMBIENT DRIVEABILITY SUMMARY

SERVICE VEHICLE REFERENCE CONDITION PROCEDURE LINE BULLETIN # --------- --------- ------- ---------- Surge After Hot Soak * Canister F, G PSB #86-650-113 Which Is Eliminated Purge Delay When The EVAP Canister Harness Asm. Is Disconnected.

* Use only on applications listed on the appropriate reference bulletin. This delay harness should not be used on 1987 and newer model vehicles that are equipped with closed loop purge systems.

Surge After Hot Soak Free Flow F, G PSB #86-650-102 Which is Not Eliminated Carburetor Main Metering a)when The EVAP Canister Jets Is Disconnected.

Surge After Hot Soak Carb. Blower F PSB #87-650-110 Which Is Not Eliminated Fan Kit

a) when the EVAP Canister Is Disconnected And b) Free Flow Carb Main entering Jets Have Been Installed.

Deep Sag At Wide Open In Tank F PSB #84-6-233 Throttle (WOT) Normally Electric Occurring At High RPM/Or Fuel Pump Near Shift Points On Kit Automatics.

Tip In Hesitation On A Accelerator F,G PSB #87-650-120 Warm Engine Pump Check Ball Spring Kit

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.