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TPS on a Honda BF75 EFI 2007, art. nr?

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Pikeman59

Member
Does somebody know the art nr. on the Throttle Position Sensor on a Honda BF75 EFI 2007? Honda only sells the complete Throttle body?
All help appreciated.

Pikeman59
 
I'm no expert on the BF75D but, sadly, it looks as if the TPS is only sold as part of the throttle body assembly as seen on item #3 in the link below.

https://www.boats.net/catalog/honda...ta-2007-and-later/silencer-case-throttle-body

It appears that the TPS and the MAP sensor both come with the throttle body while, strangely enough, you could purchase the MAP sensor (item 11) separately even though it's
100+ coconuts with shipping.
It's hard to know why they do stuff like this but they do. I suppose it's because most people don't know how to adjust a TPS these days so they don't even want to let us try.

The TPS sensors are not a high fail component on most engines so I hope that you have thoroughly tested the TPS and are positive that you actually need a new one. It is probably the easiest sensor on the engine to test and a good quality multimeter is usually all that's needed to "sweep" it through it's range to detect any faults with it's operation.

Good luck.
 
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Agree with jgmo, I 've worked on these from their inception and have never had a faulty TPS, even after submersion in saltwater
 
Alan Hicks said:
Care to discuss why you believe you have a bad TPS?
Click to expand...

I have a twin setup with Honda BF75 EFI 2007 and I switched everything between the engines to find out why suddenly the starboard engine lost 400-500 rpm at WOT. Switched ECU:s, coils, injectors, props. And changed plugs, fuelfilters, high and low pressure, high pressure fuelpumps and checked the fuel pressure = OK. fuel hoses changed and of course external fuel filters. The only thing I can think of is the TPS because I have a erratic idle on that engine and that engine works perfectly fine and inline with the port engine but the last 20 of throttle opening doesnt do a thing to rpm and speed but the port engine revs just fine up to 5800. I have had this problem a long time and a Honda mechanic checked the engine and no error codes whatsoever. Maybe its the TPS that is malfunctioning at throttle opening? I will do a TPS check tomorrow, AGAIN, and then we will see. This engine drives me crazy.
 
Your Honda mechanic should have checked the actual function of the TPS, DrH shows the varying voltage output in real time. If he can't do that then I suggest you swop the throttle bodies over, this things a bloody expensive to replace just to see if the problem goes away. Maybe try another Hinda dealer too, there's a lot more you can do with DrH than check for fault codes, anyone can do that using the MIL light system
 
Agree with doing a bit more "swaptronics" troubleshooting in this case. Since you're fortunate enough to have a good running engine to swap throttle bodies with, you should take full advantage.

If the problem follows the TB then you'll KNOW it's probably the TPS or throttle body in some way.

If the problem doesn't follow the swap then I would say that you may have a fault in the TPS wiring or in one of the connectors. Like Ian says, the Dr.H should tell what the signal return from TPS is. But, you can also backprobe the connector to get throttle setting voltages with a multimeter and then compare those to the good running engine readings. This can be done with Key On Engine Off (KOEO) and manipulating the throttle from idle, part throttle and full throttle.

If the signal is "skewed" the the sensor 5 volt reference and ground will need to be physically investigated. Often, something like this is simply a matter of a poor connection due to looseness, corrosion or a bad fit between pin and socket in a plug. Occasionally it's a bad wire in the harness.This sort of.stuff almost never logs a fault code either.

Keep in mind that each wire in the harness is made up of multiple strands of wire twisted together. If a wire has broken strands or is loose in a crimp from flexing, if only ONE strand is still intact and making contact, it will transmit a voltage signal. BUT...it will likely NOT be able to conduct the amperage necessary to make the circuit actually work correctly. This can fool you into thinking that the wiring is ok when it isn't.

The best way to see if a given wire will conduct electricity from point A to point B is to remove it from the circuit (especially from the computer) by unplugging the connectors at both ends and then LOADING it by connecting 12 volts at one end and a light bulb at the other. I use a spare tractor headlamp for doing this. If an 18 or 22 AWG wire and it's connectors can make that lamp shine bright I know that it is in good shape. It also helps to flex the wire middle and ends to make sure that the lamp doesn't flicker either.

I can see how frustrating this is for you and I, along with everyone else here, wish you the best of luck getting this thing sorted out.
 
Tested the TPS on both engines and used the Honda shop manual and also tested the voltage at idle and WOT.

Starboard engine ( the one that lost 400-500 rpm)
Ground OK
Voltage 5.01
Resistance in the TPS 0.67 ohm at idle - 1.13 at WOT.
Voltage 0.55V at idle - 4.8V at WOT

Port Engine (The good one)
Ground OK
Voltage 5.0V
Resistance in the TPS 0.67 ohm at idle - 1.29 ohm at WOT
Voltage at idle 0.48V - 4.03V at WOT

Any thoughts about the numbers?

Thanks

Pikeman59
 
My thoughts are that there IS some obvious difference between the two....

...the most significant being the WOT voltage.

In my experience with automotive TPS the 4.8 volts might....MIGHT.... be "out of range"

I typically like to see 4.5 volts maximum but I have seen higher on perfectly running engines with no complaints. While the higher signal voltage DOES match up with being a possible out of range condition and does match up with what you are experiencing.....

.....would this make me condemn the TPS?
In most cases, YES.

BUT....in MOST, or at least many, automotive instances I can swap out a new TPS for under $50!

In THIS case, it's around $400!

It's your $$$ and your call but if it were me and I was staring at a "known good" part that I could try before spending the cash....I would do the swap first and test the performance empirically.

Good luck.
 
jgmo said:
My thoughts are that there IS some obvious difference between the two....

...the most significant being the WOT voltage.

In my experience with automotive TPS the 4.8 volts might....MIGHT.... be "out of range"

I typically like to see 4.5 volts maximum but I have seen higher on perfectly running engines with no complaints. While the higher signal voltage DOES match up with being a possible out of range condition and does match up with what you are experiencing.....

.....would this make me condemn the TPS?
In most cases, YES.

BUT....in MOST, or at least many, automotive instances I can swap out a new TPS for under $50!

In THIS case, it's around $400!

It's your $$$ and your call but if it were me and I was staring at a "known good" part that I could try before spending the cash....I would do the swap first and test the performance empirically.

Good luck.
Click to expand...

Thank You for Your input. I think I will switch the throttle bodies and see if the lack of RPM follows the throttle body. If so I will try to find a new TPS or maybe a used throttle body that works fine. I found a TPS on ebay that looks exactly as my original one and should, at least regarding to the seller, fit the Honda BF75.
Original New Turn Right Throttle Position Sensor TPS SN2329 For Honda BF75 | eBay
 
Well, as a guy that has worked on cars, trucks, heavy equipment and even military tanks (my job in the U.S.Army)....I have grown VERY leery of AM (after market) parts in the last couple of decades. But, having said that, I recently put an AM TPS on my beloved old Gen1 Durango 4x4 and it works just fine.

So...your Ebay find could be a real bargain. I hope so anyway.

But your decision to do the swap and see how it runs first I think is a wise one. That will definitively answer the question.

If you do decide to try the AM TPS, make dang sure that the internal circuit matches that of your Honda before powering it up. If it doesn't and you end up sending the reference volt output directly to ground that might possibly destroy the ECM. Not trying to scare you but I really don't trust our replacement parts stream these days at all!

Please keep us informed about how it goes.

Good luck.
 
jgmo said:
Well, as a guy that has worked on cars, trucks, heavy equipment and even military tanks (my job in the U.S.Army)....I have grown VERY leery of AM (after market) parts in the last couple of decades. But, having said that, I recently put an AM TPS on my beloved old Gen1 Durango 4x4 and it works just fine.

So...your Ebay find could be a real bargain. I hope so anyway.

But your decision to do the swap and see how it runs first I think is a wise one. That will definitively answer the question.

If you do decide to try the AM TPS, make dang sure that the internal circuit matches that of your Honda before powering it up. If it doesn't and you end up sending the reference volt output directly to ground that might possibly destroy the ECM. Not trying to scare you but I really don't trust our replacement parts stream these days at all!

Please keep us informed about how it goes.

Good luck.
Click to expand...

If I can get my hands on a TPS, new or used, is it hard to dial in to the throttle body?
 
It's got to fit pretty much exactly in the hole with the slot in the sensor matching up with the end of throttle plate shaft.

You don't want any air and dirt to leak past the sensor.

The one in the picture you sent has slotted mounting holes for adjustment.

You would want to adjust the voltage values to get as close to the ones you measured on your good engine by sliding it under the screw heads.

You could actually try slotting your bad sensor's mounting holes and try to get a better adjustment on that one the same way. I've actually seen that done before as a good ol boy fix when a replacement wasn't available.

Do any adjustment with the screw heads as tight as you can and still allow the sensor to move. That way, when you cinch the screws, the settings won't change as much.
 
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jgmo said:
It's got to fit pretty much exactly in the hole with the slot in the sensor matching up with the end of throttle plate shaft.

You don't want any air and dirt to leak past the sensor.

The one in the picture you sent has slotted mounting holes for adjustment.

You would want to adjust the voltage values to get as close to the ones you measured on your good engine by sliding it under the screw heads.

You could actually try slotting your bad sensor's mounting holes and try to get a better adjustment on that one the same way. I've actually seen that done before as a good ol boy fix when a replacement wasn't available.

Do any adjustment with the screw heads as tight as you can and still allow the sensor to move. That way, when you cinch the screws, the settings won't change as much.
Click to expand...

Adjusting the existing TPS may be a good idea to start with. The holes in the original TPS is slotted so adjusting it as close as possible to the other TPS is doable.
 
Was down to the marina today to try and calibrate the TPS and found out that the TPS is mounted on the throttle body with some type of rivet instead of an allen or standard bolt. Totally missed that one. :( Is it a rivet or is it threaded and can I saw a groove in the round head and screw it out with a screwdriver?
 
That is why I suggested swopping throttle bodies if you insist on experimenting without diagnostics. You cannot simply screw on another TPS, if it is faulty you have to replace the whole throttle body, it's very expensive if it is not the problem
 
I am well aware of that the throttle body is one unit together with the TPS. But is the TPS riveted or with a machinescrew that is treaded?
 
My guess is that it's probably riveted. If it is, swapping out the TB and testing performance is probably your best bet.

You can always grind the rivet heads off later if you find that the swap works out and you still want to try adjusting as a cure.

After all, once you know for sure that is the problem you can safely assume the TB in it's present state is "junk" and you won't be ruining an assembly that isn't at fault.
 
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Okay, this is ny last bit of advice on this subject. Swop them over to confirm it is faulty, once you remove that sensor you have stuffed that throttle body and may be replacing it for nothing and still end up with the same problem. I have seen so much money wasted on this forum where parts have been swppped oit unnecessarily.
 
Just re reading, rough idle is not caused by a TPS, this has all the symptoms of low compression pn one cylinder, have you done a compression test?
 
Yes I have and compression is perfect on all cylinders, what else to expect after 280 hrs.

OK I will swap the throttle bodies and see what happens. If I cant adjust the TPS I better swop them. Bummer.
 
It's not that hard and will hopefully elliminate guess work. Failing this, you should check the support bush in the midsection for the drive shaft, they can also sap horsepower.
 
Another question, is the gasket behind the throttle body reusable or do I need new gaskets?
Looking in Honda parts diagram and cant find any art. nr. for this specific gasket.
 
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