Excel L4-1468cc 1.5L SOHC (8 VALVE) (1986)
Timing Belt: All Technical Service Bulletins
Engine - Low Power/Poor Acceleration/Erratic Idle
Group:
Engine
Number:
026
Date:
June, 1991
Model:
Excel
Subject
CRANKSHAFT SPROCKET WEAR
Condition:
Low power, poor acceleration, erratic idle.
Cause:
The crankshaft is keyed to the crankshaft sprocket (timing belt sprocket) by means of flat areas on the sprocket. These flat areas may
become worn and distorted allowing the crankshaft to rotate slightly in the crankshaft sprocket. This condition then gives the same
effect as retarding the timing.
Diagnosis:
On carbureted engines: Put a socket with breaker bar on the crankshaft sprocket bolt and try to rotate the crankshaft back and forth
slightly. If the crankshaft feels like it has some freeplay and rotates slightly without moving the crankshaft pulley, the flats may be
worn.
On MPI engines:
Check airflow sensor frequency and injector duration at idle with MUT. Normal readings should be about 40Hz and 2.8 to 3.3 ms
duration. A worn crankshaft sprocket will cause these readings to be about twice as high.
Correction:
Remove the crankshaft sprocket following procedure in shop manual. Inspect crankshaft sprocket and crankshaft mating surfaces.
Replace as required.
PARTS INFORMATION
PART NAME
CURRENT
MODEL
23120-21000
'86 -'89 Excel
Crankshaft Sprocket
23120-24000
'90 - Excel
WARRANTY INFORMATION
OPERATION
OPERATION
MODEL
MODEL
OP TIME
NATURE
CAUSE
CODES
YEAR
CODES
CODE