How to manually check codes NSD90B TLDI

[kpjenk21]

I was wondering if someone could list the steps i need to take in order to check for engine codes on my 90Hp Nissan TLDI outboard. I just bought the boat from someone and when i took it out it idled fine in fwd and reverse but when i went to accelerate it would sputter and stall. It would then it had issues starting. took it home cleaned the spark plugs which were black with soot and had oil on them. once cleaned i put muffs on and it started after a couple of tries and it even accelerated fine. turned it off and now won't start again. bought new plugs, new screw on fuel flter, and ordered a new fuel filter that goes under the cowel. want to check the codes on it to see what it says. thanks!!

 

[stresspoint]

this post might help >https://www.marineengine.com/boat-f...i-errors-and-self-diagnosis-functions.466019/

 

[kpjenk21]

okay so i figured out how to self diagnose. now to what it means...

codes i got were:

batter voltage abnormally low
battery voltage low
faulty #2 TPS
#1 tps power supply low
#2 tps power supply low

would this be a faulty Throttle Positioning Sensor or just too low of voltage...hence "battery voltage abnormally low" code?

 

[MattFL]

Taking a guess, I would say the low battery voltage is leading to the low TPS voltage. Most likely it's a 5V tps, check the wires to the TPS and see if the V+ line is giving anything close to 5V. If the TPS is getting 5V then you might have a faulty TPS. If the TPS is getting something less than 5V then my best guess is the problem is upstream of the TPS.

 

[stresspoint]

test the battery voltage with the motor idling then gradually speed the rpms up .
post back results.

 

[kpjenk21]

Taking a guess, I would say the low battery voltage is leading to the low TPS voltage. Most likely it's a 5V tps, check the wires to the TPS and see if the V+ line is giving anything close to 5V. If the TPS is getting 5V then you might have a faulty TPS. If the TPS is getting something less than 5V then my best guess is the problem is upstream of the TPS.

measured voltage at the TPS and it is reading 5V. Got boat started with muffs on battery measured 13v got to rev the engine up some to see what voltage would do and it stayed the same. Motor didn't like the rev up and spit sputtered and stalled. I'm guessing due to TPS issue...Friday all new gas lines that run between tank and motor come in so i will do another test run once that stuff is switched out. Guessing i should order a new TPS?..

 

[kpjenk21]

test the battery voltage with the motor idling then gradually speed the rpms up .
post back results.

13v at idle stays same at rev up even though the rev up isn't very strong due to spitting and sputtering and eventual stall out.

 

[MattFL]

Next check if the TPS is working properly. You need to supply 5V to the TPS then check the feedback wire to read 2 things: (1) what does it read at idle, and does that value match the spec in the manual, and (2) does the value change smoothly as the throttle opens. If it does not then there's a problem with the TPS. From what you're describing, it's a possibility that your TPS might be bad. You can either plug the TPS in and back-probe the feedback wire with a pin and use a multi-meter, or you can use a tool like this (click here for Amazon link). The video on the Amazon listing shows how it works.

 

[kpjenk21]

Next check if the TPS is working properly. You need to supply 5V to the TPS then check the feedback wire to read 2 things: (1) what does it read at idle, and does that value match the spec in the manual, and (2) does the value change smoothly as the throttle opens. If it does not then there's a problem with the TPS. From what you're describing, it's a possibility that your TPS might be bad. You can either plug the TPS in and back-probe the feedback wire with a pin and use a multi-meter, or you can use a tool like this (click here for Amazon link). The video on the Amazon listing shows how it works.

Thank you! I went ahead and ordered a new TPS. Hopefully this helps with my issues. It stands to reason that it will considering the issues I'm having. Once it's on I can then see if anything else pops up on the codes. Looks pretty easy to install 4 bolts..only other thing on it is that metal arm I'm guessing that just pops out somehow?

 

[MattFL]

Check if the TPS itself has slots or round holes for mounting. If it has slots, you'll need to adjust it to a specific value when you install the new one. If it has round mounting holds then just bolt it on, though there may or may not be a TPS calibration procedure for the ECU in this case. The service manual will be your friend here.

If it has slots, BEFORE YOU LOSEN IT take a reading at idle. If the TPS is working properly at idle, then you can adjust the new TPS to the same value and most likely it will be fine.

This short video might help you understand how it works, and why it might behave the way it does if it's bad.

 

[stresspoint]

that output not changing is a bit of a worry, even as it sputtered it still should have gone up slightly , at least .5 of a volt.
next test is to test the voltage regulator and the stator output coils, post back results.

some early fuel injection ECU s have a trigger voltage , just a thought ,i am wondering if you are not quite making enough to reach a stable voltage to keep everything running correctly ???

 

[pvanv]

As I mentioned on that other forum, I would expect at least 14v when running. There is a procedure, spelled out in the Factory service manual to set the TPS initial value. If that's wrong, all bets are off. You MUST reset the TPS initial value after replacing it. The FSM for the C model is good to use and still in print. Only thing different is your model has a slightly lower (about 10 psi) pressures for fuel and air.

 

[MattFL]

As I mentioned on that other forum, I would expect at least 14v when running. There is a procedure, spelled out in the Factory service manual to set the TPS initial value. If that's wrong, all bets are off. You MUST reset the TPS initial value after replacing it. The FSM for the C model is good to use and still in print. Only thing different is your model has a slightly lower (about 10 psi) pressures for fuel and air.

Out of curiosity; on that model motor, do you adjust the TPS itself (slotted mounting holes, rotate the sensor to adjust it), or is the TPS itself fixed and you instruct the ECU to learn whatever the TPS reads at idle?

 

[pvanv]

The TPS is fixed. You set the TPS initial setting in the ECU.

 

[kpjenk21]

Check if the TPS itself has slots or round holes for mounting. If it has slots, you'll need to adjust it to a specific value when you install the new one. If it has round mounting holds then just bolt it on, though there may or may not be a TPS calibration procedure for the ECU in this case. The service manual will be your friend here.

If it has slots, BEFORE YOU LOSEN IT take a reading at idle. If the TPS is working properly at idle, then you can adjust the new TPS to the same value and most likely it will be fine.

This short video might help you understand how it works, and why it might behave the way it does if it's bad.

Ok, so i replaced the TPS sensor but still no luck starting. however, it did clear the TPS error codes in diag mode. Still was getting low voltage codes though so i got a new battery. cleared codes, and now have no error codes at all, yay.. Still cannot get it to start. I have replaced the water/fuel seperator, the white fuel filter, the fuel line and primer bulb, and even bypassed the water/fuel seperator. is there a way to check if the black high pressure fuel filter is clogged? undo the outlet hose and see if gas flows out? i contacted my local boat guy but have a few weeks until he can fit me in. so until then i'm up for any suggestions... sprayed some starting fluid and it tries to get passed turning over but just cant get there and stops turning over altogether.

 

[pvanv]

Check fuel and air pressures, as I mentioned on that other forum.

 

[kpjenk21]

Check fuel and air pressures, as I mentioned on that other forum.

Can you send me an Amazon or auto parts store link to an acceptable gauge that would work for fuel and air pressure checks?

 

[kpjenk21]

Check fuel and air pressures, as I mentioned on that other forum.

also, the motor won't start. am i able to get an accurate fuel pressure reading by just turning the motor over?

 

[pvanv]

Pressures should be close. I get my Tohatsu tools from Tohatsu:

TLDI PRESSURE GAUGE KIT​

Description
Dual gauges allow for testing of both air and fuel pressures simultaneously. Connects to shrader valves at fuel rail.

Liquid filled gauges for accurate pressure readings. Prevents erratic needle movement during testing.

A must have for TLDI technicians.

Can also be used to check fuel pressure on our EFI 4-stroke models.
Part #: 3T5728808M
List Price (MSRP): $510.13

 

[kpjenk21]

Pressures should be close. I get my Tohatsu tools from Tohatsu:

TLDI PRESSURE GAUGE KIT​

Description
Dual gauges allow for testing of both air and fuel pressures simultaneously. Connects to shrader valves at fuel rail.

Liquid filled gauges for accurate pressure readings. Prevents erratic needle movement during testing.

A must have for TLDI technicians.

Can also be used to check fuel pressure on our EFI 4-stroke models.
Part #: 3T5728808M
List Price (MSRP): $510.13

OOF! $510 for a damn pressure gauge. i'll have to find something cheaper.