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Tohatsu TLDI 90 -06 problems

Termari

Member
Hi,

I have a couple of issues with Tohatsu (MD90B) which no one in Finland seems to know anything about.


Few weeks ago engine started coughing when trolling. When I quickly gave it more rpm it put out a huge amount of exhaust and I could continue trolling for like a 15-30 mins until same thing happened. I kept going two more trips, but problem got worse and it started coughing after 10mins of trolling. I was told that the engine uses too much oil. Possible uses the oil % that is used when driving 4000rpm or something like that or it has left the running in -mode on.
Also sometimes when trolling engine raised rpm itself.


I read the diagnostics and it gave me codes:
4500rpm - battery-light ON - Oil-light flashing.
And 4000rpm - battery light ON.
And 4000rpm - battery light ON - OIL light flashing.


I found this engines MD90B service manual and it gives nothing on the first one.
And some battery failures on those two other.


So, I bought new battery with 993cca and thicker wires. Thinking that my old battery wasn´t enough for the ECU and caused that "too much oil" -problem. I also erased the fault codes and did the ECU/TPS reset.
But now engine didn´t even start. It tried but didn´t start.


Found out that the cabels were istalled wrong, I adjusted the cabels so the advancer arm now touch the close-stopper and did the TPS/ECU reset again. Now engine starts but it dies everytime i put gear on.



So, I tried to fix a problem but caused another one. Help, what next?


Ps. Found a MD90C service manual and it shows Oil pump malfunction on that first fault code..
 
I would go to Tohatsu.com and check the dealer locator. With your issues, someone knowledgeable should probably look at it.
 
I would go to Tohatsu.com and check the dealer locator. With your issues, someone knowledgeable should probably look at it.

Yes, that would be great, but seems impossible. From tohatsu.com you can find the finnish dealer Sumeko Co. Tried to call them, but any number I can find isn´t in use, for real, none of them. From site sumeko.fi you can find company named Star Service - which is Tohatsus service. Called them and told my problem (which then was only this coughing when trolling) and they had no idea what it could be and their advice was to buy smaller engine just for trolling.

Now I have called at least 10 different outboard service place that has Tohatsu -logo on their website, but everyone says: "I have no idea, we have had very few of those come here. Have you changed the plugs?"

One service I called said he had some contact in Sumeko Co and asked him, but that guy didn´t know anything.

So I really really would like to have someone knowledgeable check for that engine, but I can´t find anyone from this country.
 
I am certified on TLDI, but it's difficult to dx on a forum. Not sure about Finland, but many dealers in the US. The codes are similar on all TLDI, you you may be over oiling, and may have other issues. The mechanical oil pumps are solid, but the ECU controls the electric pumps, so many possible issues.
4500, bat, oil flash is a failing oil pump
4000 and bat is battery low
4000, bat, oil flashing is battery very low.
I would VERIFY all grounds and power cables, up that battery (as you did), then clear codes and reset TPS and check again.
 
I am certified on TLDI, but it's difficult to dx on a forum. Not sure about Finland, but many dealers in the US. The codes are similar on all TLDI, you you may be over oiling, and may have other issues. The mechanical oil pumps are solid, but the ECU controls the electric pumps, so many possible issues.
4500, bat, oil flash is a failing oil pump
4000 and bat is battery low
4000, bat, oil flashing is battery very low.
I would VERIFY all grounds and power cables, up that battery (as you did), then clear codes and reset TPS and check again.

Okay, thanks.

I did that. Codes are clear and reseted TPS. Starts fine, but idle (900rpm) feels quite low. If I use key to change between (900-800-700) it dies when I go to 700rpm. I have no other equipment to read the rpm than the tacho and it´s not that accurate, but I would say from that it´s more like 800-700-500.
 
Full info is in the Factory service manual. You must use DFI oil, not just tcw-3.

Do you mean this throttle link rod? Image below. And by settings, that TPS is reseted when this rod hits it's "close" mark?

I've been using quicksilver DFI oil, made for optimax.
 

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OK, 2% is about 50:1. That's OK at wide open, but should be a lot less at slower speeds.
I believe you have the electric fuel pump, which is controlled by the ECU, based on throttle position and RPM and load (vacuum).
The TPS determines when the ECU thinks the throttle is closed. The initial TPS setting must be right or everything else can be off.
Your videos show taking up slack in the various linkages; that's normal.
If you are still getting an oil pump failure code, the pump may be bad, dumping too much oil.
At this point, it's only a guess, but an informed one.
 
OK, 2% is about 50:1. That's OK at wide open, but should be a lot less at slower speeds.
I believe you have the electric fuel pump, which is controlled by the ECU, based on throttle position and RPM and load (vacuum).
The TPS determines when the ECU thinks the throttle is closed. The initial TPS setting must be right or everything else can be off.
Your videos show taking up slack in the various linkages; that's normal.
If you are still getting an oil pump failure code, the pump may be bad, dumping too much oil.
At this point, it's only a guess, but an informed one.

Ok. Thank you for answering so many questions so far!
 
Back at solving this problem. Hoping to get the engine working for this summer.
Bought a new oil pump and about to change it, but I wondering how can I make sure there won´t be any air in the oil line after the change?
Found a guide from manual to air bleed (?) the line from oil tank to oil filter, but how to do the same for the rest of the line. Before and after the oilpump?
 
Full info is in the owners manual and the service manual. Mostly, you can gravity bleed the system.
 
Full info is in the owners manual and the service manual. Mostly, you can gravity bleed the system.

Ah. Found it. Had a wrong manual. Sorry.

Another dull one: How could I make sure all the oil hoses from the pump goes to a right place? Previous owner has dissembeld the engine, so could there be a chance hoses from the pump goes wrong and causes dumping too much oil.
 
Thought the new oilpump fixed the problem. 2.5 h trolling and worked fine. Now two weeks later all ****ed up again. Dies when putting gear on. Plugs are like dipped in oil. What would be your next guess, pvanv? Im starting to think it’s the TPS sensor..
 
I read the faulty codes, it gave nothing. And reseted the TPS.
This is what the plugs look like. It´s 3. and 1. plug. nr. 2 was quite dry.
Tulpat.jpg
 
You can test the TPS sensor. I would also verify idle speeds. Check how much oil you are using. And clean or replace those plugs.
 
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