Engine Cranks Over but Will
Not Start or Starts Hard
2. Determine if there is fuel present by looking down
the carburetor venturi while actuating throttle.
There should be a stream of fuel coming out of
the accelerator pump nozzles if the carburetor
has fuel.
Important Information
3.
Check ignition system operation. Remove coil
wire from tower on distributor cap. Hold coil wire
near ground and check for spark while cranking
engine over. Repeat procedure with spark plug
wires. If there is spark at the spark plug wires, re-
move the spark plugs and make sure they are
correct type and heat range, and not fouled or
burned.
1.
First, determine which engine system is causing
the problem. To make an engine run, basic com-
ponents - fuel, spark (ignition), and compression
-
are required. If all three components are pres-
ent, the engine should run. If any one of the three
are missing, weak, or arriving at the wrong time
the engine will not run.
4.
Run a compression check on engine to make
sure the engine is mechanically OK.
Thunderbolt IV (HEI) Ignition (No Spark)
Cause
Moisture on ignition components
Battery, electrical connections, damaged wiring
Ignition switch
Special Information
Distributor cap or spark plug wires arcing
Shift interrupter switch (Alpha One Models Only)
Shorted tachometer
Disconnect tachometer and try again
Ignition timing
Spark plugs
Fouled, burned, cracked porcelain
Faulty insulation, broken wires
Spark plug wires
Cracked or dirty distributor cap
Faulty ignition components
Check components
Engine synchronizer (if equipped) hooked up
series on purple ignition wire (dual engines only)
Synchronizers must be hooked up directly coil
terminal (parallel chute)
Index
90-823224--2 796
TROUBLESHOOTING - 1C-7
| Categories | Mercury MerCruiser Manuals |
|---|---|
| Tags | Mercury MerCruiser 454 CID, Mercury MerCruiser 502 CID |
| Model Year | 1993, 1994, 1995, 1996, 1997 |
| Download File |
|
| Document File Type | |
| Copyright | Attribution Non-commercial |
(4 votes, average: 4.5 out of 5)
Marine readers have rated 1993 1997 Mercury-MerCruiser GM V8 454 CID 7.4L and 502 CID 8.2L Marine Engines Service Manual Number 16 4.5 out of 5.0 based on 4 product reviews. Hugely helpful service manual! Perfect. Thank you!
Manuals are all Important for Technician
This book is invaluable if you do your own repairs. Great book.
Could not find a copy until a search brought me here.
Excellent print.
Thank you