2003 yamaha f115txrb surging

[SkunkBoat]

Exploded views & part#s

http://www.boats.net/parts/search/Ya...XRB/parts.html

Have you tried spraying carb cleaner in the throttle bodies and air control valve?
see "Intake2" diagram, #10. Looks like maybe an air filter #13 on the control valve assy also...

[steplift20]

No we didn't do that but we think it's the throttle positioning sensor If we put it in doesn't look to hard, I heard it has to be adjusted, does it ? and how do I do it

[spareparts]

leave the tps alone, if you dont have the software or a voltmeter dont mess with it. unless its idling odd, the tps is probably ok. there is a chance it could have a dead spot, but its hard to find,. You can try this trick, with the engine running and the cowl removed, tap on the computer with a screw diver handle, not real hard. See if it changes te way it runs. F115 computers are known to give issues.

[steplift20]

It is idling odd, at mid range and low range like putting it on the trailer ,( high range is fine, ) but what your saying is I do need to adjust it the tps I will tap on the computer to see if it does change

[THEFERMANATOR]

You can pick up a cable and software off of ebay for $120 I believe I paid. If you were closer, I'd hook it up for you. I'm not sure if I could copy my disk, but I've heard you can find the software online to download, then you get a usb to obd2 cable, and make 3 jumper wires to connect it(I opted for the premade cable because I wanted it to be a clean connection).

[steplift20]

Ferm thanks for the offer, I'm not to good with computers I live in nj Northern part, the problem is if I bring it in to a marine mechanic you know it's going to be very expensive, it always is and the issue I'm having is pointing to the TPS

[SkunkBoat]

Originally Posted by steplift20

Ferm thanks for the offer, I'm not to good with computers I live in nj Northern part, the problem is if I bring it in to a marine mechanic you know it's going to be very expensive, it always is and the issue I'm having is pointing to the TPS

the air control valve controls bypass air when the throttle is closed or near closed.
The computer adjusts the open/closed timing of the valve by looking at the intake air pressure(there is a pressure sensor there) From my experience on my suzuki, your symptoms are exactly what happens when the iac valve isn't working right.

If I were you, I would do the simplest things first...
1- remove the air filter on the valve and see if it gets better
2- spray the crap out of the throttles and the iac valve(remove the hose and really get in there) and see if it gets better.
3- clean the contacts of the plugs on the iac valve and the air pressure sensor

If none of that helps, you need diagnostics. You can't just start replacing things because they will require adjustment. Your best bet is a Yamaha dealer who will find the problem fairly quickly and fix it. You are going to pay for his expertise, his software, his ability to try a part he has laying around... That will probably be cheaper than buying software, a connector, and maybe not the right part(s).

I don't have a Yamaha and I'm not an outboard mechanic but I did stay at a Holiday Inn....
Are there no blinking indicators on your Tach that might be telling you what is wrong?
I was lucky, the Suzuki flashed a code that pointed to the IAC valve timing.
The Service manual($7 download) had an adjustment that could be done without a computer.

[THEFERMANATOR]

Originally Posted by steplift20

Ferm thanks for the offer, I'm not to good with computers I live in nj Northern part, the problem is if I bring it in to a marine mechanic you know it's going to be very expensive, it always is and the issue I'm having is pointing to the TPS

Tps can cause surging, but so can any of the other sensors on the engine. Pull a $100 bill out of your wallet, light it on fire, if this doesn't bother you, then by all means start throwing parts at it. If it does bother you in any way, pay the money and have it scanned. Way to many engines become projects and end up sold or parted out because people started guessing saying this part points to it, or that. Seen it happen too many times, and don't like seeing it.

[steplift20]

I was just told that a code for the pulse coil came up ,does that sound right to you guys?

[spareparts]

they should have found the pulse coil issue with a spark check on the first trip