Hesitant ignition Mercruiser 5.7

[cheswest]

Hi All,

looking for a diagnosis protocol for a hesitant ignition on 1997 5.7 Mercruiser (carb) Thunderbolt ignition. When I turn the key, I get either a "no go" or a 3-4 second "nothing" and then it fires normally - same power as always. I was told that this is a starter issue, so I got a new starter (not usually my technique to use the parts scatter gun approach) but this wasn't it...anyone have a checklist or know of one online to guide me in eliminating possibilities...from the key to the starter. This problem did not happen gradually - like a slower start - it went from not happening to happening.

Cheers

Ches

 

[Scott Danforth]

first, check all your battery cable connections from the battery to the motor. every connection should be shiny metal, and tight. what you are describing can be due to a bad or corroded or loose connection.

 

[alldodge]

I get either a "no go" or a 3-4 second "nothing" and then it fires normally

If your saying you turn the key and nothing, but if you hold it at start position, in 3 to 4 seconds its starts to crank?
Or if you turn to start, and after doing it a few times it will start to crank

Then check your slave relay on top the motor. When key is turned to start there should be 12V on the small terminal Yellow/Red wire, this energizes the relay. You can also jump across the larger top 2 terminals and it with engage the starter

 

[Bondo]

I get either a "no go" or a 3-4 second "nothing" and then it fires normally -

Ayuh,...... Please explain this statement,.....

While the motor is crankin' on the starter, the ignition is supplied battery voltage, by the outer tiny terminal on the starter's solenoid,.....
Once ya let go of the key, the ignition is powered by the key switch,.....

 

[cheswest]

Bondo, I mean - I can have 20 tries and it doesn't turn over at all. Leave it a while, try again and it may go at first touch or maybe after 3-4 seconds turned. Very random.

 

[cheswest]

Thanks for the tips everyone, going to hit the slave solenoid with the multi meter as well as batteries and go from there. As always, brilliant forum. Cheers

 

[Bondo]

Bondo, I mean - I can have 20 tries and it doesn't turn over at all. Leave it a while, try again and it may go at first touch or maybe after 3-4 seconds turned. Very random.

"Hesitant ignition Mercruiser 5.7"

Ayuh,.... So it's a hesitant Starter,...... Not a hesitant Ignition,......

 

[Scott Danforth]

see post #2. by shiny, the connections must be cleaner than your wife's fine china and your kids must be able to eat off of it. if anything looks green and corroded, throw it away and replace it.

 

[Walt T]

I wholeheartedly agree with the above mentioned check your connections. I have run into a starter that sounded bad that turned out to be a bad ground cable connection at the bellhousing.. Pull cables and clean them. If they have rusty steel lugs replace them with copper. I've found rusted steel automotive cables that caused other shops to replace starters and the frustrated boat owner ends up at my shop. I hear the story and do the basics first.... CLEAN CONNECTIONS

 

[cheswest]

Update - started with batteries - all seemed good - well greased and clean Moved on to slave solenoid with the "field medicine" technique of grounding with a screwdriver while key was turned...cranked right away. So, I guess we have a winner. Cheers folks. Always a brilliant source of help and information.

 

[achris]

When you turn the key and nothing happens, what happens to the instruments? Do they go dead, or stay on? Do you hear a 'click' from the engine compartment?

Chris........

 

[cheswest]

Final results....bought and installed new slave solenoid, boat now has a hair trigger startup. Fantastic all. From the most Eastern Tip of North America, grateful thanks to all.