Cuts Out/Misses

SYMPTOM DESCRIPTION
Steady pulsation or jerking that follows engine speed, usually more pronounced as engine load increases. The exhaust has a steady spitting sound at idle or low speed.



SYSTEM OR COMPONENT TO CHECK ACTION




IGNITION CHECK CYLINDER MISS:
CAUTION Do NOT perform this test
for more than 2 minutes,
as this may cause damage to the
catalytic converter.
- Start engine, allow engine to warm-up.
- Shut off engine, disconnect IAC motor.
- Restart engine and remove one
spark plug wire at a time
using insulated pliers.
- If there is an rpm drop, on all cylinders,
(equal to within 50 rpm),
- Reconnect IAC motor with ignition "OFF."
- If there is no rpm drop on one or more
cylinders, or an excessive variation in drop,
check for spark on the suspected cylinder(s)
with J 26792 (ST-125). Spark Tester or equivalent.
-If there is spark, remove spark plug(s)
in these cylinders and check for:
- Insulation Cracks
- Wear
- Improper Gap
- Burned Electrodes
- Heavy Deposits
- SPARK PLUG WIRES Resistance should not
exceed 30,000 ohms, also check rotor
and distributor cap.
NOTE If the previous checks did not find the problem:
- Visually inspect ignition
system for moisture, dust,
cracks, burns, etc.
- With engine running spray plug
wires with fine water mist to check
for shorts.




FUEL CHECK - FUEL PRESSURE Related Tests, Information and Procedures
- FUEL QUALITY
- Restricted fuel filter.



ENGINE CHECK COMPRESSION Perform a compression check
and cylinder leak down test.
Look for low compression, sticking or leaking valves.
VALVE TIMING Remove rocker covers, inspect
for bent pushrods, worn rocker arms, weak
valve springs or worn cam shaft lobes
RESTRICTIONS Intake and exhaust system for
casting flash or other restrictions.