Mazda MX-5 1990 Workshop Manual page 167

TROUBLESHOOTING GUIDE
F
STEP INSPECTION
5 Check for air leakage of intake air system
c::7'
page
F-93
6
Check if airflow meter vane moves smoothly
7
Check for correct engine compression
c::7'
page B-1 0
Engine compression: 1,324-932 kPa
(13.5-9.5 kg/cm
2
,
192-135 psi) - 300 rpm
8 Check if spark plugs are OK
WEAR AND CARBON BUILDUP
PLUG CAP
~~ii~
1.0-1.1mm
(0.039-0.043 in)
BURNS
DAMAGE AND
DETERIORATION
DAMAGE
9 Try known good ECU and check if condition
improves
c::::r
page F-127
ACTION
Yes Repair or replace
No Go to nest step
Yes
Go to nest step
No Repair or replace
c::7'
page F-92
Yes
Go to next step
No Check engine condition c.:r page 8-10
- Worn piston, piston rings or cylinder
wall
• Defective cylinder head gasket
• Distorted cylinder head
-Improper valve seating
• Valve sticking in guide
Yes Go to next step
No Repair, clean,
or
replace
c:::r page G-20
05UOFX-020
F-23