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MD508 Tiller 2008 Startup issue

D

DJD

New member
After the numerous warranty-covered issue of fuel starvation, blamed on Southern climate(Florida) and ethanol, the Tohatsu installed a transom-mounted fuel pressure booster unit. This worked, although not perfectly 100% of the time. They eventually upgraded to a more powerful unit to replace the initial after further, continual dealer bringbacks. Very frustrating experience to say the least, although Tohatsu has admitted to several other motors having same issue.
Recently, now, out of warranty, I have developed a startup issue...although this only happens intermittently, while out fishing. The "on" position has its typical audible and visual cycle before silencing, the start position will yield ZERO. Removing the 15A fuse(pt/t & ignition) to examine yielded 0 visual break. I reinserted same fuse and it then started. This was occurring while fishing about 20 % of the startups. I coated all fuses(with factory rep recommendation) with dielectric grease. While out fishing yesterday, it only happened twice, but still a pain in the arsenal!
BTW, I have tried new fuse replacement with same results.

Thanks in advance
DJD
 
Intermittent electrical issues are the worst. You could have a bad/fractured wire near the fuse, a marginal switch, flaky solenoid, etc. It will likely take time and patience to find the issue. If popping the fuse out/in always fixes the issue, look in that area. The start schematic is pretty simple, so you could use a good volt meter to probe while engaging the start position. For example, it would help to know whether the switch is sending 12v to the solenoid... whether the low-current circuit to the start terminal of the switch is getting 12v, etc.
 
Thanks Paul for the courtesy of a quick reply. further details from yesterday revealed that the drive pinion gear was staying in the raised position which I guess for safety, would not allow electrical continuity that would disallow the startup attempt. I forced it down and the continuity was re-established. After inspecting my battery specs, I found the possible culprit...the CCA was 550 and my manual recommends 800- 900 CCA. Even though I have used this battery for 18 months with no issue, I guess replacement to a larger power plant is viable. I'll let you know, thanks again.

Doug(in sunny Fla.)
 
Doug,

I would inspect/clean/lubricate the "starter bendix" (the drive that extends up to the flywheel) to maker sure that it pops up when start is called, and drops back down after starting; otherwise, the starter mechanism may get damaged by being engaged while the motor is running. Typically, the higher speed of the running flywheel forces the pinion gear to retract down, but that may not happen at slow speeds.

There is a possibility that the starter did jump up when you hit the start switch, but did not have enough current to crank the flywheel against the compression of the motor. That could be because of a low battery, or a poor connection (such as corrosion in a wire connector), or a defective starter (or solenoid) itself.

Yes, it's best to use a high-amp battery on any TLDI. 1000 MCA (or better yet, 1000 CCA) is preferred, usually available in a group 27 or 31 battery. It's important to note that all lead-acid batteries lose capacity over time, and while your 550 CCA battery was adequate on a hot day a year ago, it has less "wallop" today. Also, batteries tend to have lower capacity as the temperature falls. So you are getting a double-whammy of cooler temps and an aging battery. The usual issue with a battery that does not have adequate capacity is that while the starter will crank the motor, during cranking, the voltage drops to the threshold where the ECU doesn't initialize properly. That can lead to all sorts of weird operation problems. If that should happen, the TLDI will usually start, but run poorly. The correction to that issue is to replace the battery with an adequate one, and then reset the TPS initial setting... Often the first thing we will do in the shop.

If I had the motor in our shop, I would start with a better battery, carefully inspect all wiring connections (especially grounds), check over the starter motor, and if there are still problems, troubleshoot from there. Be advised that the TLDI (or any DFI motor of any brand for that matter) is a complex machine, and is not really "shade tree mechanic" friendly; you will want a Factory service manual (from any dealer) -- not an aftermarket manual (which is too general) to do any maintenance/repair beyond regular operating of the motor. One nice features of the TLDI is that the ECU can tell you any problems it has seen and recorded. You need the Factory service manual (and a Factory tachometer) to perform those tests.

Because of the learning curve associated with a TLDI, we typically recommend seeing your dealer for service. But if cost and convenience make that impractical, you can certainly study the manual, and, armed with average mechanical ability and proper tools, you can do most of the service/repairs yourself.
 
Well i have had continual issues since purchasing the TLDI50. Same as what you are having now. I am based in Australia and in the end I gave up with the engine. Asked the dealer to trade the engine out to a 4 stroke. Will be done by next week. TLDI had less than 25 hours and 3 months old
 
Sorry to hear about your "struggle", what year was your motor. Good to hear that Tohatsu allowed the alternative. When the TLDI functions as designed, it runs like a scalded cat,lol!! No perfect world, good luck with the 4 Stroke.
Doug
 
engine was 3 months old

Tohatsu has brought nothing to the table

All was done by the dealer

yes when it was running it went like a scalded cat that is for sure
 
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