Slow and No Starting

[juice69]

Got a Mercruiser 3.0L (2004), and just changed the manifolds and riser. Everything looked fine, and noticed nothing out of the ordinary. Started her up yesterday (it took a few cranks as has been the case when cold) four different times throughout the day to make sure everything was ok. Changed the spark plugs (they were pretty black from running rich), and was hoping that would eliminate the slow starting issue. No luck. It cranks a couple times and then slows down to no crank (as i said it's always been somewhat of slow starter when cold). Had the battery tested - and it came back fine. Cleaned up the terminals and connections. Still no go. Checked the alternator and solenoid, and they're both getting power. I did notice that when i took out the last time about 6 weeks ago that the 2nd battery was showing like 9.5 volts on the gps, which seemed odd and not correct as it was showing 12.7 at the post. I hope this is just a starter going bad, but wanted to hear advice from those that know more.

 

[MarkSee]

Re: Slow and No Starting

I had a very similar starting problem last month as you and even though the battery was showing 12.7 and the battery charger was showing it fully charged multiple times, the slow-cranking to no-crank problem continued. Went ahead and bought/installed a new battery, it fired right up and no issues since. Is there a way you could borrow an almost new battery of the right size and cold cranking amps and see if the problem goes away?
Mark

 

[juice69]

Re: Slow and No Starting

I'm sure i could find something. I tried starting again later this evening, and i would get one click and that's it (not even the slow turning engine). What's odd is that my second battery for the house electronics is equally as bad! They're on a seperator (and not even hooked up now), but who knows if that works right anymore! Trying to get the starter off to have it tested is a pain. The bolt on the bottom won't budge. Sprayed with some liquid wrench and will try tomorrow.

 

[Technorunner]

Re: Slow and No Starting

If you have both batterys installed and one of them is bad , the bad battery will drain the healthy battery. So if you have 2 batterys paralell connected i would disconect the one you dont use for start and make sure the other one is charged to full and then try and crank it over and se if it cranks better. A friend of mine had that problem until he installed a switch between the batterys. before the batterys was connected to each other and then to the battery switch so he got back after 3 days, completly empty both of em.

 

[bnicov]

Re: Slow and No Starting

You need to have the batteries load tested. That's the only semi accurate way to let you know what condition they are in. If one is bad, it will suck power from the good one and soon both will be pooched since we are talking about cranking batteries and not deep cycles which are meant to be discharged and charged many times.

 

[Don S]

Re: Slow and No Starting

1. Loose battery cables.... Throw the wing nuts away and get some regular nuts and tighten with a wrench.
2. Corroded battery cable terminals..... Clean the terminals on all the battery cables (each cable has two ends)
3, Defective battery cables & ends ...... Check the cables, if the crimped on terminal ends are loose or corroded, or the cable is damaged and swelled up in spots, the cable is junk.
4. Defective starter. It happens.

 

[Silvertip]

Re: Slow and No Starting

As you are cranking the engine, have someone monitor the battery voltage - AT THE BATTERY TERMINALS. As cranking begins to slow watch for a corresponding drop in voltage. If there is, you have a bad battery. If it doesn't you have bad battery cables or connections. Check the cheap stuff first. You can also jump directly from the battery POS post to the starter solenoid to see if that helps. If it does, it again points to cables.

 

[juice69]

Re: Slow and No Starting

Thanks for the input everyone. To update – right now I’m just getting a single click when I turn the key:

1. Checked the battery under load by hooking it up to my truck, and it started right up. So the battery is not the cause.
2. Checked the breaker on top of the engine, and that is not tripped.
3. Checked the run/safe lanyard switch and it is in the run position.
4. Checked the connections on the solenoids, and they are all getting power (thanks Don, great write-up in the adults only on troubleshooting starting system). I didn’t check the ignition switch yet, but that’s because initially I was getting a slow crank.
5. I cleaned the battery terminals (only the starting battery is hooked up and being used – the house battery is completely off line). I could cleanup the solenoid connection a little better, but I’ll do that after I’m able to get the starter off. I couldn’t get to the ground wire hitting the engine, but I can (and will) bypass this for testing with a good jumper cable back to ground though.
6. Tonight I will use a brand new cable running from the battery to the starter solenoid, and also test by jumping the slave solenoid.

Finally, does anyone have any tips on breaking loose the bolt underneath the starter that holds it in place? I hit it with some wd-40 last night, and hopeful it moves now.

 

[MarkSee]

Re: Slow and No Starting

For a chemical solution for breaking bolts loose, see the below topic and what I have extracted for a mixture that says it will work. When I googled these chemicals, several posters swear this works for loosening bolts/nuts.

Frozen 470 engine/bell housing bolts, motor mount bolts, etc
http://forums.iboats.com/showthread.php?t=528175
Here is a penetrating oil recipe from TomSawyerOwner
"a secret mixture to break loose stuff like this. I was shocked how well the stuff works and I'll never buy another can of penetrating oil again. 50/50 mix of Dextron transmission fluid and acetone. just soak the (part) good and let it sit for a while or even overnite. this mixture is amazing I put it on anything rusted that needs broke loose. Even removed the brake bleeders out of my 1988 bronco with a open end wrench like they were installed the day before."

 

[juice69]

Re: Slow and No Starting

Got the starter off and it was dead so replaced it. Up running and sounds great, not to mention a bunch of clean electrical connections. Thanks to everyone for their help.