2004 Tohatsu 90hp tldi error code 7000 and the battery light

fizzle15

Cadet
Joined
Sep 2, 2010
Messages
17
howdy,
I've got a 90hp tldi outboard that has been surging at idle and then also, doesn't want to just throttle up without some finessing. As in if I raise the throttle too fast it seems to sputter and lose rpms. - its new this year - it hasn't really stalled, but it seems close to it. It also runs great from 3000 to 5000 rpms.
at any rate I checked the codes on the gauge and it shows 7000 rpms and the light furthest to the right (that I think is the battery light). I checked my manual and that combination is not there.
Any ideas what it could be.
so far this year I had to get a new battery. and I replaced the fuel vacuum regulator as I thought that was the cause of the surging.
thanks for your help
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
I assume your model is MD90B.

What in the heck is a fuel vacuum regulator?
What manual are you using?
7000 and battery is a FFP issue. Could be a severed line or a pump problem. That info is right in the Factory service manual.
What are your air and fuel rail pressures?
 

fizzle15

Cadet
Joined
Sep 2, 2010
Messages
17
I assume your model is MD90B.

What in the heck is a fuel vacuum regulator?
What manual are you using?
7000 and battery is a FFP issue. Could be a severed line or a pump problem. That info is right in the Factory service manual.
What are your air and fuel rail pressures?
yup md90B - that's a 2004 90hp Tohatsu tldi.
the fuel pressure regulator is what I intended to say - its the vacuum line in the air / fuel rail.
the service manual I have is maybe 345 pages its got a green cover.
it has ffp issue for 7000 and the first light. nothing for 7000 for the third light. - thought it might be different. actually hoped it was something different.
I haven't checked the pressures - I don't have the right fitting for the little shredder valve in my pressure set.
is it for a ford? what size is it.
but yeah - new fuel pump two years ago and it runs at great at high speed - but the transition from idle to speed is rough.
thanks for your help
 

fizzle15

Cadet
Joined
Sep 2, 2010
Messages
17
I assume your model is MD90B.

What in the heck is a fuel vacuum regulator?
What manual are you using?
7000 and battery is a FFP issue. Could be a severed line or a pump problem. That info is right in the Factory service manual.
What are your air and fuel rail pressures?
what factory service manual do you have?
I think I'm going to need a better one if I'm going to keep this thing any longer.
I went back to check mine again - it doesn't have anything for 7000 rpm and oil light off - temp light off - and battery light on.
so its a crap manual -
let me know what you've got - so I can get it too.
thanks for your help
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
Unfortunately, the original MD90B manual is out of print. But the MD90C,( which is available from any dealer), manual has the same codes. The schaeder valves are metric; you can get an expensive gauge set from Tohatsu, or use a tire gauge.
 

fizzle15

Cadet
Joined
Sep 2, 2010
Messages
17
I found an online service manual - for the md90c - it also, doesn't have anything for the oil light - off - temp light - off - and battery light on with 7000 rpm.
Could I trouble you for a photo of the page from your manual?
thanks for your help
 

pvanv

Admiral
Joined
Apr 20, 2008
Messages
6,500
Beware online Factory service manuals; they are copyrighted, and anyone putting them online risks serious legal pursuit. Have you verified the FFP operation?
 
Joined
Sep 12, 2022
Messages
3
Seem to be having a similar is as the previous person I changed the plugs , and all of the sudden it started surging from 1500 rpm to 3000 then it and the lower end locks up when I put it in gear and stalls 2006 model md90b 3t9 s#037638xe I've purged all the air from the system. By doing pumping the bulb and then releasing the top float bolt till the air is out . Have not checked pressures , not really sure how to do that. HELP !!!!
 

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pvanv

Admiral
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Apr 20, 2008
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So it ran fine until you changed plugs? What the heck is a top float bolt? Gauges go on the schraeder valves on the fuel and air rails.
 

MattFL

Master Chief Petty Officer
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Oct 20, 2010
Messages
827
The lower end locks up when you put it in gear? Can you elaborate on that, do you think the gearbox is locking up?
 
Joined
Sep 12, 2022
Messages
3
The lower end locks up when you put it in gear? Can you elaborate on that, do you think the gearbox is locking up?
No it spins fine and then it starts to idle up and then locks up and kills the motor . I think after further research the air compressor is messed up or the tps messing up or throwing an error .the reason I say the compressor is the plugs are wet with fuel when it acts up . I don't think the gears are locking up I think the compressor is locking up stopping the engine. After is locks up I can put engine in gear and turn motor manually to unlock it .
 

MattFL

Master Chief Petty Officer
Joined
Oct 20, 2010
Messages
827
Ask yourself, if the air compressor starts coming apart is it possible for it to put bits of metal into the motor? If yes, then you may want to remove and disassemble or at least give it a good inspection before running it more, if you think it's the air compressor that's locking up.
 
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