TLDI cutting out when the boat slams

[whosmatt]

Hi all,

Took a trip out 18 miles from San Diego harbor today. On the way back, I ran close to full throttle for quite some time. When I'd hit a swell and the boat slammed down, the motor would cut out for a split second. This is a 50 TLDI purchased in Feb this year. There weren't any alarms, and the motor ran great otherwise... I ran it WOT for a while in the bay when i got back and it was fine then. The oil level was relatively low when i got back, but not low enough to set off the alarm.. maybe 1/4 of the tank. Just wondering what might cause this.

Thanks,

Matt

 

[TOHATSU GURU]

Re: TLDI cutting out when the boat slams

Loose wire somewhere.

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Loose wire somewhere.

Where would you start if you were troubleshooting this? I'm going to check the battery connections first, but after that?

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Loose wire somewhere.

I think I may have found it... With the motor running on the muffs, I wiggled the battery cables at the battery and under the cowl, nothing changes. Then, I moved on to the next obvious thing... the kill switch. I found that with the lanyard inserted, I can bump the switch from beneath, basically just pushing it in a little, and the motor dies. This makes sense. I guess I'll run it down to the dealer and have them replace it. Thanks,

Matt

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Yep. Old thread, but it's mine so I'm resurrecting it.

Update. I did replace the kill switch, even though I hadn't been able to replicate the problem since the occurrence described in my original post. Anyway, fast forward almost a year, and another 100 hours or more on the motor, and I'm still having issues. Basically the motor will seemingly randomly cut out for a split second, just lose rpm, then pick up as if nothing happened. Seems to happen at any rpm, regardless of conditions -- but not very often. Sometimes I'll run a whole day with no problems, sometimes it happens a couple of times an hour.

So, I figured I'd grab the diags from the tach. Here's what I found: Overheat condition: see my previous posts for this one. I know when/how that happened. CPS fault. Assuming this got logged because of the RPM changes, due to the note in the service manual. Finally, FPP fault.

So, I went over the basic stuff... checked the plugs (actually replaced them with the original ones that came with the motor, the ones I took out after 10 hours) cleaned and re-gapped. Checked my fuel fittings, found that I was pumping air with the bulb so I removed and re-seated the connections and was able to get it to stay firm both while stopped and while running. I adjusted the throttle cable a touch to get it to seat against the stop while at idle, and then reset the TPS according to the manual instructions.

Fired it up after these steps and it seemed to run fine, perhaps a touch smoother than before, though hard to tell on the hose.

Took it to the water and ran for an hour or so. No problems for a while, but I was (finally) able to reproduce the original problem I posted about, by crossing a wake at WOT and slamming the boat. Once again it cut out for a split second, and then continued running as normal. I was able to get this to happen 3 or 4 times. Unfortunately, I didn't clear the codes before doing this, so I'm not sure if I got any additional info.

I've wiggled every electrical connection I can touch with the engine running and can't reproduce the problem other than by launching the boat off a wake, and then only sometimes.

So... what do I check next? If I take it to the dealer, do I just tell them to launch the boat off a wake until they witness the issue?

Thanks,
Matt

 

[82rude]

Re: TLDI cutting out when the boat slams

so if your launching off a wake, if your motor clears the water, would you not be hitting the rev limiter?

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Possible, but don't think so. The motor is running generally 5400 rpm at WOT, trimmed out. If it was hitting the rev limiter I'd expect to hear it rev up first, as it has a ways to go before the limiter kicks in. I've had the limiter kick in when the prop loses bite and it doesn't seem like the same thing.

-M

 

[TOHATSU GURU]

Re: TLDI cutting out when the boat slams

It has to be a loose or bad connection somewhere. Unfortunately, the only way to find it is if it is bad while the test procedures are being run. You may have to live with it or at least live with it until gets bad enough to show up in a static test.

 

[whosmatt]

Re: TLDI cutting out when the boat slams

It has to be a loose or bad connection somewhere. Unfortunately, the only way to find it is if it is bad while the test procedures are being run. You may have to live with it or at least live with it until gets bad enough to show up in a static test.

I figured. I'm going to re-rig the motor this weekend or next, and I'll check out all the wiring that I can then. I built this boat myself and my battery cables and control cables are a little short for a clean install with a nice loop at the motorwell, so I'm going to pull new ones, and will be disconnecting the harnesses in the process to run everything through a new rigging tube so I'll get to examine the connections up close.
After that, I'll clear the codes, see if I can reproduce the problem, and see if it sets any codes.
Thanks for the replies. The motor has been flawless other than this little hiccup, no pun intended.


Matt

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Well, I did the re-rig. It looks much better now, at least. I took it out on the water to test out a new prop and when I throttled up after clearing the no-wake zone the motor died.. Figured out pretty quickly it was the PTT fuse. Replaced it with the spare and went on my way. Then, it happened again, once I throttled up to a certain point. I debated calling vessel assist but since I was only half a mile from the ramp I took the spare 25A fuse from the fuel pump and idled home. Best I can figure is that I pinched a wire in the control box when I put the new throttle/shift cables in, or that my harness connectors still have some cable pulling lube in them, causing a short. I blew them out with compressed air, but maybe that wasn't enough.

The good news is that I got to examine the cables from the control box / gauges to the motor, and they look good. I was worried that maybe one had been compromised by me pulling other wires through the chase tube after they were installed.
Matt

 

[whosmatt]

Re: TLDI cutting out when the boat slams

Best I can figure is that I pinched a wire in the control box when I put the new throttle/shift cables in
Matt

Yep. Anybody know why they make the wire from the tilt trim switch so long? It got jammed and sliced the outer jacket and the jacket of the "hot" wire when I pushed the throttle control forward... hence the short. Seems like there's a lot of slack cable packed into the control box. The full range of movement doesn't require nearly that much as far as i can tell.

https://lh5.googleusercontent.com/-...a2ma2xns/w653-h441-no/IMG_20130928_120908.jpg

 

[whosmatt]

Re: TLDI cutting out when the boat slams

I took the boat out one more time after repairing the damaged wire in the control box and making sure they weren't binding anywhere.

I will say this -- I think I may have been over-propped before, the new prop makes the motor sound much more happy, and she didn't miss a beat, except once, again when the boat slammed. It didn't set any codes.

Anyway, I'm happy for now; I feel like the motor runs well and the occasional missing (not to be confused with the cutting out problem) I described in the post that resurrected this thread seems gone. I dropped an inch in pitch in the same prop model and gained 300+ RPMs. Not sure why that would be the case, but with a light load (no fishing gear, no passenger, no ice, empty bait tank) I can take it to 5800 rpms WOT, and I think my tach might read a tad low. Hole shot is quick, top speed is the same, but it just feels better and the motor sounds better at all speeds. Less vibration too. Maybe I just had a bad prop.

So - to recap the thread and my steps:

1. Motor cuts out for a split second when the boat slams (sometimes). Hard to reproduce. Have to run very fast in rough water.

2. Over time, the last year or so, the motor has had an occasional miss at any RPM, usually lower. Seemed to get worse over time.

3. I replaced the plugs, reset the TPS and ECU. Problem #2 seems much better, problem #1 is still there.

4. I re-rigged with new battery cables (to the console) and new control cables, for cosmetic purposes. In doing so, I pulled all the wiring from the console to the motor out of the chase tubes and examined it. No problems found. I was looking for jacket and insulation breach from using unlubricated pulling rope. I also installed a new prop at this time, dropping an inch in pitch (props are same mfg and model, just the pitch is different).

5. Test run discovered I had pinched a wire in the control box, causing a short and blown fuses. Test run aborted.

6. Test run #2 the boat runs great, was able to reproduce problem #1 once and had to try very hard to do it. No other problems, apparent improvements all around.

7. I'll stop posting now unless something else crops up. Thanks for the help.



Matt