2006 DF175 Charging/idling issues

[redlowrey]

The reason I asked about the battery is, with a fully charged battery and even with the alternator not charging and the engine at idle would not drop the voltage to 10 volts at the battery. If I was chasing the problem the next step would be fitting a 0 to sixty amps in either direction meter in series with the sixty amp fuse and see just what is going on.

[Harper2]

I think Red is onto something here. I cannot figure how you could be charging all five batteries with one DF175 (if that is indeed the case). Maybe the three trolling batteries aren't on the charging system, but I ask because I wouldn't expect you to mention them if they weren't involved in the equation. And with with #2 battery cable running to the starter, I'm not surprised your engine quit when you disconnect the white wire. The motor should keep running with the white wire disconnected. It won't start reliably that way, because of the voltage drop via the main ECM relay during cranking without it. I have two batteries, charged through the dual battery isolator system, and 00 battery cables to the motor. I used to have an occasional starting problem, even with the white wire hooked up. The problem was that the batteries were not fully charged, especially after a number of starts throughout the week. At the time, the batteries were not split into house and start battery functions. But since rewiring the factory setup, I've not ever had the problem again. Outboard motors don't have real hefty alternators like some cars. I top off my batteries with a charger before putting the boat away after every week-long outing. And not having a trolling motor, mine are never drawn down anywhere near what yours would be. Do you put your batteries on shore chargers at all when the boat is not in use?

[artdf175]

valve tool,,thanks.. I try to be creative where possible.. if was reasonably priced I would just have purchased one..
5 Batteries? send pictures.. I guess I am having difficulty with 3 for trolling motor.. unless it is electric..
I agree with Harper in the house and starter should be wired using the isolator arrangement..
how do you have the 3 trolling batteries tied into the system?

the sucking sound ..maybe not good..
while the mechanic is checking valves.. should have him do a compression and leak down test..

and as Red mentioned try a fresh new battery.. to do a good test . disconnect all the other batteries .. that will eliminate a lot of guessing.. IF by chance that works.. start adding batteries back to system and IF it is a battery arrangement problem..you should find what is wrong
good luck and keep us posted

Thanks for all the help and expertise. I have 5 batteries in the boat, 2 for house and cranking and 3 for trolling motor. Art nice job on the valve tool. I appreciate manufacturing at home it's tough but rewarding. Every single connector and terminal have been wire brushed shiny including the ones under the cowling. While the motor idles rough it seems to make a loud sucking sound right before it quits. It may just be the sound a motor makes right before it quits, I am not sure. I am currently waiting on the mechanic to adjust the valves. We'll see!

[captchancey]

As far as I can tell the motor at above 1200 rpm's or so runs great just like it always has. The top speed is the same and the load on the motor seems just as powerful as the first day I drove it. The 3 batteries are hooked to a 36volt trolling motor and they are charged with an onboard charger consistently. The boat has a new battery as of 2 weeks ago. The battery's are wired to an isolater switch for house and cranking.

[artdf175]

Good evening
I just did a long reply this phone just deleted
Anyway. Understand
Is there a chance the charger for the trolling batteries are sucking so much that the overall voltage drop below specs
Have you tried isolating he motor and battery from the rest of the system and testing ?
You might review the specs for that charging system and see what kind amps it is drawing down
I will have to get the manual out again to tell you what the specs are on the big motor. It puts out 12V @ 3000 rpm but don't remember the amps
Give the isolation idea a try
Art

[RussArran]

From the manual:

Output: 12V 44A (528W)/3000 RPM
Regulated Voltage: 14.2 - 15.2 V

You might need a solar panel... ;-)

[Harper2]

As I understand it, your trolling batteries are not hooked up to the outboard at all, correct? If so, we can eliminate them from the conversation. Let me ask you this, Ben... do you have a service manual? The procedure for checking the charging system is too long and there are too many checks for everything to be posted on the forum. If you don't have the manual, you really need to get one. There are a number of checks to do on the charging coils and continuity checks at numerous places that need to be systematically performed so as not to skip over and miss something. To take any hit-and-miss approach is thus far proving to be fruitless, and will likely continue to do so. Use another multimeter to check your voltage at the voltmeter terminals to confirm that the gauge is accurate to start with, then if the voltage is really that low, start the procedures in the service manual.

Concerning the idle problem, again the manual is essential. It will be one of the components in the engine management system, a MAP sensor, temp sensor, IAC, TPS, who knows? Again, unless each step is done, everybody will just keep chasing his tail on this one. Have your service center hook up a computer to it. I really don't think we're going to solve this the way it's going.

[captchancey]

Correct Harper
No service manual. I am trying to get a mechanic in to do the valve adjusting right now. I will let you guys know the outcome then. Thanks for taking all the time you guys have already. I really appreciate it.

[captchancey]

Now I am being told I need to remove the injectors and have them professionally cleaned to fix the problem. They believe the poor idling at low idle is coming from a clogged injector that will open at high rpms but not low rpm's. I am skeptical but will get it done. The mechanic said there is almost no chance the valves are making it idle poorly.

[captchancey]

I went to Suzuki tech today and they said it was the idle control valve and then I said I replaced it. They then told me to back off the idle screw in the throttle body. Once I took the screw completely out the engine it would idle and not quit. However the idle was increased to about 1100 rpms. If I put my hand over the throttle body completely it will still idle but if I cover the little screw hole it will idle down and shut down. They pretty much checked all the things you guys mentioned on here. It all looks good. Still no fun!

[Harper2]

Any progress on the system voltage? I've been thinking about that one a bit, and am wondering why the motor even keeps running if the voltage is truly that low, since there have been numerous instances of the ECM just shutting everything down because it didn't like the low voltage it was seeing. Have you tested the voltmeter for accuracy? I also just recalled that when my boat was a couple months old, the Faria voltmeter went bad, reading way low. Faria replaced it under warranty.

Now with your latest post, I'm wondering about the mechanic's comment on the injectors. Pressure at the fuel rail should be pretty much the same at idle and at speed, and the ECM varies the pulse duration to adjust fuel amount, so I thought that it didn't make much sense that they'd perform at one RPM and not the other. But it got me to thinking that if your voltage is really that low, and the ECM still allows the motor to run (which it obviously does) then the lowest voltage at idle might just be causing the injectors to struggle to open properly, getting just barely enough to activate the coils, but then they'd get enough voltage at a higher RPM to not be affected, and all would smooth out. Just grasping at straws here, it sounded good to me.....oof, it's a tough one.....

[captchancey]

I appreciate any and all help. Nearly everything that has been mentioned I have rectified it if I could. Today I ordered the computer software and connectors that will allow me to read all the codes on the computer as well as the service manual. I am stubborn and don't like for things to beat me. I'm still fighting. The local suzuki dealer couldn't get me in until next weds so I have to get on the ball now. Thanks for all the help.

[redlowrey]

Fix the charging problem first, then worry about the rough idle. I find it hard to believe that you cant find the problem, you have replaced the two main components, unless the magnets fell out of the flywheel or the sixty amp fuse has blown it should be easy to find. Do some voltage drop tests from the battery, starter motor, from the white wire that goe's from the solenoid to the terminal block, the output wire from the rectifier to the terminal block check the fifteen amp fuse and the thirty amp fuse although they wont stop it charging. Rough idle can be caused by numerous things air leaks, dirty injectors, uneven compression, tight tappets, worn cam lobes, bad plugs, leads, coil packs. low battery voltage causes low primary voltage saturation in the coils reducing spark out put,and slow injector operation, pulse width modulation is also effected. All these things will make the engines manifold vacuum eratic and because the map sensor uses manifold vacuum for information the signal line voltage will be all over the place.

[captchancey]

I will be taking the injectors off tomorrow and have them cleaned. The computer software should be here by Friday and then I will run a diagnostic to see what else may be the problem. Today the Voltage on the Voltmeter stayed above 12V all day, sometimes a little above 12.