Mirage L4-1597cc 1.6L SOHC Turbo (1985)
Ignition Cable: Customer Interest
Engine - Turbo Cross-Fire Shock
SUBJECT:
TURBO CROSS-FIRE SHOCK
NO.
STB-85-08-011
DATE
June, 1985
MODEL
1985 Turbo Models
BACKGROUND Cross-fire shock can be felt as a severe miss or engine harshness, particularly at intermediate engine speeds under boost conditions, as
for example, ascending a freeway grade in 5th gear. It is most likely to be felt when the ignition cables are moist or dirty. Cross-fire shock occurs when a
spark plug fires prematurely on the compression stroke. The mixture in the cylinder ignites, trying to force the piston down backward, and this causes the
"shock". It is the same as random unexpected spark advance. The cause is incorrect routing of the spark plug high-tension cables and/or the cable from
the coil to distributor.
DIAGNOSIS TIPS
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On automatic-transmission models, this condition may be mis-diagnosed as ELC damper clutch vibration.
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If the ELC is disconnected, the torque converter absorbs the engine speed change, making diagnosis difficult or masking the symptom
entirely.
CORRECTIVE ACTION
Cross-fire shock can be eliminated by connecting the ignition secondary cables properly to the coil, distributor and spark plugs, and by supporting the
cables so they do not touch each other. The following sketches show the required connection patterns and routing for the ignition secondary cables on
Starion, Cordia/Tredia and Mirage. Be sure to include the coil secondary wire when checking the cable routings!
