Turbocharger System Troubleshooting; Insufficient Acceleration, Lack Of Power Or Excessive Fuel Consumption - Toyota 7M-GE Repair Manual

TURBOCHARGER SYSTEM - Troubleshooting TC-5
TROUBLESHdOTlNG
NOTE: Before troubleshooting the turbocharger, first
check the engine itself. (Valve clearance, engine compres-
sion, ignition timing etc.)
INSUFFICIENT ACCELERATION, LACK OF POWEk OR
EXCESSIVE FUEL CONSUMPTION
(Possible Cause)
I
1. TURBOCHARGING PRESSURE TOO
LOW
t
(Check Procedure and Correction Method)
Check turbocharging pressure. (See page TC-8)
Turbocharging pressure:
M/T 0.39 - 0.53 kg/cm2
(5.5 - 7.5 psi, 38 - S2 kPa)
A/T 0.34 - 0.42 kg/cm2
(4.8 - 6.0 psi, 33 - 41 kPa)
If the pressure is below specification, begin
diagnosis from item 2.
2. RESTRICTED INTAKE AIR SYSTEM
Check intake air system, and repair or replace
'1
parts as necessary. (See page TC-7)
J
.
3. LEAK IN INTAKE AIR
Check intake air system, and repair or replace
parts as necessary. (See page TC-7)
.
4. RESTRICTED EXHAUST SYSTEM
Check exhaust system, and repair or replace parts
as necessary. (See page TC-7)
Check exhaust system, and repair or replace parts
as necessary. (See page TC-7)
6. ERRATIC TURBOCHARGER
OPERATION
Check rotation of impeller wheel. If it does not turn
or turns with a heavy drag, replace the turbocharger
assembly.
Check axial play of bearing shaft. (See page TC- 14)
Axial play:
0.13 mm (0.0051 in.) or less
If not within specification, replace the turbocharger
assembly.