2006 mercruiser 350 mag crank but no spark

saurd

Cadet
Joined
Oct 4, 2007
Messages
24
I have a 2006 mercruiser 350-mag MPI Serial number OW348398. It will crank with no spark so will not start. Still in the driveway. Following are some of the things I have checked thus far –
  • Replaced to Coil Module and Coil PT number Sierra Part 18-5465 due to getting a fault ‘EST 1’ – that fault is cleared
  • Verified no spark from the coil
  • Verified the CPS by seeing a RPM reading 130 on the scanner plugged into the ECM diagnostic plug while cranking the engine.
  • Verified the fuel pressure at the fuel rail of 43 psi when cranking the engine. Also noticed the scanner is only reading 2.1 psi of fuel pressure, is there an electronic pressure sensor, if so were is it and how can that be checked out?
  • Verified the neutral switch, continuity in neutral and open when in gear.
  • Verified the kill switch is in the correct position.
  • The 3 fuses in the holder mounted top of the engine are all good. The main breaker appears to be OK. Are there any other fuses to be checked?
Looking for other possibilities. Trying to avoid just replacing parts.

Thank you in advance for your help.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,572
Have you tried replacing the distributor cap?

You have the HSV distributor and while the caps mat look good they go bad quite often. So often many carry a spare
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,123
There isn't a fuel pressure electronic pressure sensor for these engines. The 2.1 should be a default setting or more part of the fuel injector pulse width possibly.

Do you hear a/the normal first key on warning beep?

Though you saw RPM on the scan tool, do you see the tachometer gauge moving too? Technically speaking, 150 RPM would be to low and usually that's hard to see on a scan tool at crank, the RPM's should be closer to 300 - 400 RPM at engine crank. < If low, ensure your battery 12 volt power and Cold Cranking Amps are up to your manual specifications.. Very important on your engine.

Depending of type of tachometer gauge installed on your boat, you may want to try disconnecting either the gray wire at the tachometer or unplug the wire harness plug if a newer type gauge and see if the engine starts up for you.

AllDodge's mention of trying a new cap and rotor is a very strong possibility even if you're not seeing spark out of the coil side due to being a solved issue before for many for unusual phenomenon type reasons.

Being a bravo drive, by chance have you installed a new sea water pump impeller recently and now an issue? If so maybe you have a damaged wire type problem down behind the crankshaft balancer area at the crankshaft position sensor.

All that mentioned and since you had a coil code issue, you may have lost your coil driver within the ECM which is repairable as mentioned here, https://whipplesuperchargers.com/index.php?dispatch=products.view&product_id=73
 
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