5.0 Merc crank no start

[onsiteservice]

Didn't have a lot of time to work on this Saturday going back today to try and diagnose. It's a 2003 Ebbtide with the 5.0 merc with the electric in-line fuel pump. The engine cranks fine but has no power to the fuel pump and the distributor is not firing. Ran fine the day before, checked the drivers safety switch it's OK. What other safety switches would kill fuel and ignition but still allow the engine to turn over? If none, then does anyone know if the power supply to the pump and the distributor are on the same circuit? Both sides of the coil had power, the white w/red stripe wire had 12 volts with ignition key going into the distributor. Any help would be appreciated! Thanks, and sorry didn't have time to get the serial # Saturday....

 

[Bondo]

Re: 5.0 Merc crank no start

Didn't have a lot of time to work on this Saturday going back today to try and diagnose. It's a 2003 Ebbtide with the 5.0 merc with the electric in-line fuel pump. The engine cranks fine but has no power to the fuel pump and the distributor is not firing. Ran fine the day before, checked the drivers safety switch it's OK. What other safety switches would kill fuel and ignition but still allow the engine to turn over? If none, then does anyone know if the power supply to the pump and the distributor are on the same circuit? Both sides of the coil had power, the white w/red stripe wire had 12 volts with ignition key going into the distributor. Any help would be appreciated! Thanks, and sorry didn't have time to get the serial # Saturday....

Ayuh,.... You HAVE Ignition power...

The fuel pump runs ONLY while the starter is engaged, or after it starts, it gets power through the oil pressure safety cut-off switch...

 

[onsiteservice]

Re: 5.0 Merc crank no start

Yes sir I do have igntion power, duh....can't belive I forgot that.....(the oil pressure switch).....still can't figure out the no fire though...especially since the coil is powered up and the wires to the distributor is powered up? I haven't seen very many coils go bad without warning....or signs of overheating.....and for it to lose fuel and fire at the same time leads me to belive it's something simple that is going to make me work for it....LOL

 

[Don S]

Re: 5.0 Merc crank no start

You have power to the coil, but do you have spark from the coil. Check by removing coil wire from the center of the distributor cap, hold the wire about 1/2" from a clean unpainted ground and crank the engine. You should get a bright blue white spark that snaps across the gap. Weak, Yellow spark will not run the engine.

 

[onsiteservice]

Re: 5.0 Merc crank no start

Ok ser# is rubbed off air cleaner its an MCM 5 ltr 03 model. I hooked up another test ign coil still no fire. I'm starting to think either the pickup is bad or the control module. Doesnt the w/g wire from the module to the pickup show ground on key switch or crank? I have nothing on that wire, power or ground. W/R wire shows ground with key off and power when key on??? Boqt rqn fine the day before, put it on the lift and tried to fire next morning, no fire

 

[onsiteservice]

Re: 5.0 Merc crank no start

Just wanted to update the thread, module in distributor was bad, installed new fired up.