Mitsubishi Eclipse 1990, Service Manual

Page: 280 / 2103

ENGINE
On-vehicle
5. Cover the spark plug hole with a shop towel etc., and
after the engine has been cranked, check that no foreign
material is adhering to the shop towel.
Caution
1. Keep away from the spark plug hole when crank-
ing.
2. If compression is measured with water, fuel,
etc., that has come from cracks inside the
these materials will become heated and
gush
out from the spark plug hole, which is dangerous.
6. Set compression gauge to one of the spark plug holes.
7. Crank the engine with the throttle valve fully open and
measure the compression pressure.
Standard (at engine speed
of
1,350 (192 psi)
Limit (at engine speed of
Min. 1,020 (145 psi)
8. Measure the compression pressure for all the cylinders,
and check that the pressure differences of the cylinders
are below the limit.
Limit: Max. 100 (14 psi)
9. there is a cylinder with compression or a compression
difference that is outside the limit, pour a small amount
of engine oil through the spark plug hole, and repeat
the operations in steps 7 and 8.
(1) If the compression increases after oil is added, the
cause of the malfunction is a worn or damaged piston
ring and/or cylinder inner surface.
(2) If the compression does not rise after oil is added,
the cause is a burnt or defective valve seat, or pressure
is leaking from the gasket.
10. Connect the crankshaft position sensor connector.
11. Install the spark plugs and spark plug cables.
12. Use the scan tool to erase the diagnostic trouble codes,
or disconnect the negative battery cable than
10 seconds and reconnect it.
NOTE
This will erase the diagnostic trouble code resulting from
the crankshaft position sensor connector
MANIFOLD VACUUM CHECK
1. Before inspection, set vehicles in the following condition:
l
En
l
Lig electric cooling fan, and accessories: OFF
ine coolant temperature:
l
Transaxle: Neutral (P range on vehicles with
2. Set up the tachometer or connect the scan tool to the
data link connector.
Revision