I did a valve adjustment and took it for a ride. Everything ran fine. The next day I replaced the fuel filter as it was having an existing issue of running to redline at full throttle. It would rev up fine at full throttle up until 6500rpm then fall on its face and not be able to increase the RPM. So I replaced the fuel filter. There was an aftermarket filter in there. The little wire (grounding?) was attached to the metal body of the filter with a hose clam since that filter didn't have a little tab for it. I put in the new OEM filter and attached the little wire snugly with stainless safety wire to where it belongs. What is this little wire for?
I put everything back together and it wouldn't start. It would just crank and crank. Occasionally it would fire up for 1 revolution, but then go back to cranking. I primed the fuel pump a few times and same thing. I pulled the spark plugs and it was a little damp. I dried it off and reinstalled. Same thing. I detached the outlet hose of the fuel pump flange, turned on ignition and confirmed fuel does in fact flow.
Next day I took the fuel pump assembly back out, confirmed everything was still in place. Also removed the hoses that attach to the fuel filter, blew through it and confirmed that it was not clogged and that it was installed in the right direction. Put the assembly back in and unplugged the wiring for it. I pulled the spark plugs again, and with the plug wire still attached, grounded it to the exhaust pipe and crank it and I could see visible blue sparks as it fired. I used the engine turning tool and set horizontal cylinder at TDC from the flywheel side, then confirmed that the timing marks were aligned at the pulley side. Put everything back together and attempted to start again. This time the engine seemed to be able to fire up for a few more revs then die. I was able to keep the engine running by adding a little input at the throttle. When it did run it ran really rough and didn't sound good. If I gave it more throttle than say 15%, it would die out. Also, if I give it too much throttle as it cranks, it would make a loud pop and puff
I'm stomped at what the issue could be. What should I test next? I have read that it could be a TPS. I have a multimeter. How do I test the TPS?<br />
To sum it up:
•Has fuel
•Has spark
•Has compression
•Good timing
Whats next?
This might help:
http://bikeboy.org/ducatitps.html (http://bikeboy.org/ducatitps.html)
Are you sure all of your lines have good integrity? If a line is sucking air you will have a problem. Prime the pump by turning the key on and off and look for fuel rushing around in the tank. The ground wire is to protect the bike from going KABBOM on a fill up (static electricity).
Quote from: howie on June 08, 2016, 02:57:52 PM
Are you sure all of your lines have good integrity? If a line is sucking air you will have a problem. Prime the pump by turning the key on and off and look for fuel rushing around in the tank. The ground wire is to protect the bike from going KABBOM on a fill up (static electricity).
Are you talking about the in and out lines that are connected to the base of the fuel pump assembly under neath the gas tank? Where would I see the fuel "rushing around the tank"?
Just checked the TPS. The signal wire on the connector was slightly frayed exposing some wire underneath. I taped it up (for now) and still no start. Then tested the volt range on the TPS itself from closed throttle to open throttle. The readings were 0.39V to 4.20V with gradual increases in voltage readings as I rolled on the throttle.
This sucks. I'm temped now to open up the fuel tank (again) and throw in the old fuel filter to see what happens. Am I going crazy?
I'm referring to the hoses in the tank. "Fuel Rushing around in the tank" is the best, though poor wording I could think of at the moment. You should not see a lot of turbulence. Might be a good idea to observe on a known good injected Duc and compare to yours. What I suspect is either bad hoses or a loose clamp at the filter. This is diagnostics over the internet, so...
Oh, if you need hose you need alcohol resistant, submersible SAE 30R10 hose.
I will be testing the fuel pressure. What is spec for pressure at the fuel rail?
When I disconnected the output hose and turned on the pump, it only emptied about 2oz into my bottle. Seems kinda low...is this normal?
When I replaced the fuel filter I actually removed the whole tank and worked on it with tank upside down could this have some issue? Where is the vent for the tank?
I don't think you have all the air purged.
Quote from: SwiftTone on June 09, 2016, 09:58:20 AM
I will be testing the fuel pressure. What is spec for pressure at the fuel rail?
When I disconnected the output hose and turned on the pump, it only emptied about 2oz into my bottle. Seems kinda low...is this normal?
When I replaced the fuel filter I actually removed the whole tank and worked on it with tank upside down could this have some issue? Where is the vent for the tank?
The spec should be for pressure at the return line, and should be mid-40s. The fuel pressure regulator resides inside the tank on the flange. If the return line is blocked, the pump will overpressurize the fuel line and vent through the relief hole in the top of the pump. Not at all obvious on a stock S2R tank.
Also it will be too rich to run properly.
Quote from: ducpainter on June 09, 2016, 10:05:32 AM
I don't think you have all the air purged.
Purge it by priming the pump multiple times? I'll try it again.
Quote from: Dirty Duc on June 09, 2016, 10:32:31 AM
The spec should be for pressure at the return line, and should be mid-40s. The fuel pressure regulator resides inside the tank on the flange. If the return line is blocked, the pump will overpressurize the fuel line and vent through the relief hole in the top of the pump. Not at all obvious on a stock S2R tank.
Also it will be too rich to run properly.
Do you know which injector the fuel output hose feeds fuel to first?
Yes.
Yes, prime it again.
You should be able to hear the pump tone change as it picks up the fuel, and hear gurgling as the air purges out of the system.
S2R, it doesn't matter which hose goes to which fitting.
Quote from: SwiftTone on June 09, 2016, 11:15:37 AM
Do you know which injector the fuel output hose feeds fuel to first?
Not off the top of my head, and I don't have a stock setup anymore to look at. I don't remember whether I matched the ST outputs to the "correct" fuel hoses.
Like Speeddog says, it doesn't matter.
On the bikes with external pressure regulators it matters, but not on the ones with the pressure regulator in the tank.
So basically I can actually put the fuel pressure tester between the fuel input/return hose and the input/return connection on the gas tank flange?
You can 'tee' in anywhere along the fuel lines outside of the tank.
Okay so...little progress.
I primed the pump 30 times and I wasn't able to get it running. Then I sprayed intake manifold cleaner into the throttle bodies and it actually ran! As long as I kept feeding it through the throttle bodies it ran and actually got it up to 140 degrees F. So it def isn't a spark issue.
Next I disconnected the return hose and see what the fuel flow was like. Primed and let whatever comes out go into a container. Seems like very little fuel flow. 1-2oz per prime. I've attached a video below. Next I connected the fuel pressure tester between the return hose and input nipple on the flange. prime it a bunch of times until it got pressure. It was only able to build pressure to 5psi and once it stopped priming it would drop down to 0psi. To eliminate the possibility of leakage outside the fuel tank, I then connected the fuel pressure tester at the output nipple on the flange, only this time I plugged the end of the hose with my finger. Same results. 5psi when priming and quicking dropping off. I've attached video of this as well.
So this leads me to believe that it's something inside the actual gas tank that is faulty. I've already checked twice and made sure the hose clamps are tight. The hoses in there are the plastic type so it doens't need replacement unless its cracked. If it's a faulty fuel pressure regulator, the pressure would be too high right? So does this mean that it's the fuel pump itself?
I feel like I'm getting close! Thanks all!
Fuel pressure video: https://youtu.be/6OcTlGET3Wo
Fuel flow video: https://youtu.be/Hzo0AA03M8g
Your fuel pump sounds sick. It should make a much higher pitched whine instead of that miserable buzz.
You have those hard plastic lines in the tank? I don't think they are really reusable. Sae 30R10 hose and regular hose clamps....
Those Teflon or whatever lines are the devil.
Once it's primed, it should hold pressure for quite a while.
So either the FPR has a piece of debris in it's valve, or it's come loose/seal is compromised/?? and is leaking.
Or the intake screen on the fuel pump is plugged or....
Fprs are susceptible to alcohol fuels, although mine failed more slowly and that was with methanol...
Try new hoses and clamps first. If you suck air in you will get air out.
Clamps like this http://www.jegs.com/i/JEGS-Performance-Products/555/16046/10002/-1 not like this http://www.homedepot.com/p/Everbilt-1-2-1-1-4-in-Hose-Repair-Clamp-6712595/202309385;jsessionid=FAAD76C2ADC3D300C4F86D9EA60B5ED0
Much cheaper than a fuel pump.
Quote from: Dirty Duc on June 09, 2016, 08:58:27 PM
Your fuel pump sounds sick. It should make a much higher pitched whine instead of that miserable buzz.
You have those hard plastic lines in the tank? I don't think they are really reusable. Sae 30R10 hose and regular hose clamps....
Those Teflon or whatever lines are the devil.
Not sure what you mean about buzz. Sounds whiney to me. Maybe it's my phone microphone throwing the sound off.
How do I test the power supply? I saw 4 wires at the harness. 2 are black, one is blue/white and the other I forgot.
Quote from: Speeddog on June 09, 2016, 09:07:09 PM
Once it's primed, it should hold pressure for quite a while.
So either the FPR has a piece of debris in it's valve, or it's come loose/seal is compromised/?? and is leaking.
Or the intake screen on the fuel pump is plugged or....
If the fuel pump screen is restricted, shouldn't the system still be able to hold whatever pressure it builds?
What component actually holds the pressure? Is it the FPR? Are those replaceable?
What is the order of fuel flow through the in tank components from input hose to the output hose?
Most of the research on FPRs are ones that are mounted externally, and have vacuum hoses. How do in tank ones differ?
I'll go look at my S2R flange this afternoon. I'm pretty sure they're replaceable... but probably not listed as such from Ducati. IIRC, the S2R deal is sold as a complete assembly only.
Fuel flow:
Pump
filter
out to injectors
back to FPR
into tank
The vacuum hose on the "external" FPR is to reference/adjust the fuel pressure based on engine load. I haven't seen a Ducati that does that, they seem to leave them open (this gives a very slight adjustment to pressure based on altitude)... it is usually more useful in forced induction applications.
The internal FPR cannot be referenced to vacuum... other than that, not much difference in capability or design.
Quote from: Dirty Duc on June 10, 2016, 11:01:50 AM
I'll go look at my S2R flange this afternoon. I'm pretty sure they're replaceable... but probably not listed as such from Ducati. IIRC, the S2R deal is sold as a complete assembly only.
Fuel flow:
Pump
filter
out to injectors
back to FPR
into tank
The vacuum hose on the "external" FPR is to reference/adjust the fuel pressure based on engine load. I haven't seen a Ducati that does that, they seem to leave them open (this gives a very slight adjustment to pressure based on altitude)... it is usually more useful in forced induction applications.
The internal FPR cannot be referenced to vacuum... other than that, not much difference in capability or design.
That's really helpful. CA Cycleworks sells FPRs individually, with 2 different styles; with or without pipe on the side of it. Can you see what is on the stock one? Here's the link to the product: http://ca-cycleworks.com/fpr35x (http://ca-cycleworks.com/fpr35x)
If the flow of fuel is as Dirty Duc says ( Pump>filter>injectors>FPR>into tank), it shouldn't matter if I have a bad FPR or not when I was testing if it was building and holding pressure at the tank output hose since the only component the fuel has traveled through its pump and filter. Shouldn't there be a check valve in the fuel pump?
going to open it up the tank (again) and really look at the components. Anyway to test the fuel pump other than if it primes or not? I've seen submerged tests but I don't feel comfortable doing it with a bucket of fuel. Can I use distilled water without damage?
The fpr is the thing that holds pressure in conjunction with a check valve in the pump... sorry, I was at work earlier (which has nothing to do with internal combustion) then forgot to go out to the shed and look at the part.
If you fill your pump with water you run the risk of not getting it all out and getting it in the injectors which will compound any issue you have now.
I wouldn't.
The check valve in the pump holds "residual pressure". This allows the bike to restart easier after sitting. Your fuel pressure regulator maintains pressure while the pump is operating. Pressure can be falling off because of inconsistent volume. You can use lamp grade kerosene as test fluid as it is less flammable, about the same viscosity as gasoline and, unlike water is soluble.
Two potential failure points on the FPR:
The inside membrane, or the outer o-rings that separate the pressure side from the tank
(https://lh3.googleusercontent.com/AvkKYRkfVVlGcUT-jAh3_dt12Imh0SJzatQ4PHI_RGUuaJf3H2M2w8GlFxyRMJujZT_fPChS3HLPGNsNePvLe6Zqw0T2vIJMf2_rFxXb18739mTU9_2wk33-SMnoqJVsrfzOZvem0NzN0hOTkAOfX2UlGlsj9uVbL8Kg37AAcDxbpz5WKye_c8VRr7zX9IjXt4StE9AKTkZDzoV2nwGjKBtJqDonT_ZTTY9clhGLTrRdr3ljSRMZWOEyQdOv0i6QadmFBuRAnjvFOmQqZYzWHQEboc5vWddIn1lJ-lHx1IfAZpJqNxzhDk30gJWqXMBsqo5UYK-ebjZ3csI1LF2iU9Ymd1gPnONlaZhH-J30cEVgKofoyEnEmmuO_DLAD8b96Jk1xOeWdO8rM1ezeOfuuYgKfp0NVRe4dRTWvZlrhhlLZyp0FQt1Kx7nhenItnvO5DlHyu1ZPU9qOVHPedokLluP7MtoLGdZ63YoT9iFBke2udloOEo3IX8xv-RU3WOSMuRP8dLX6G1dKMSUxeKxD82IUFijj4GjE6QNVd1vW1cJRbd-rxkPh7zI-qdYW6HSL2WgGa7BEOJ2uuQsSpPDd3iENzANVjc=w538-h955-no)
(https://lh3.googleusercontent.com/u3fJIvgZGSYN9uI8lJVDE0UyGUD0waQKO250kb27BP2V4UP8x2KLMF5eTs_v-gf3_kyPIckWhYAOupbBpUzypyJo-1mL6k1pwc2OjQKM3dor47FCH_ZNYmt2OtfmRYMkVk0SJhXkZR-aesCntI_z2XrcoeLV5-iL0fJfucvBdOeyVq0kay2RT_gjItoolttczohnsv_tYM-ATQ19uqcxiDR5jZBxD5PM3Ah6DwYwEZlTe7xp8Pa9E1-Wy9ob7LbY31IvE97FM4z_A_XApoHxasRBP0IUitkBRzP3QWKXtqB2oB34ZSv2wTRAqvyNRSy0ql9Rt5oLMhgahv9Uy8p36STIhYWU_s9xH1EjRxDPJkXpB7QN49QIWQbCfrCPI2zt8joAb2_9Plehr36URu2gP6xmAdXaDlza7c47fLzRyypDy7rY66tqueoX1w57fV1yZSq4WYIGSKyQfXmSxyLP7jmUTbkXXhhQtluywtGJgoCvaV18WvsCBrh2eclRwwK6gShsp_pSDGVrOoalrwXUQfE9lVFNkECQXvKKsvKElUw1LUP8_z7FGZV-SyOwJxAKuaU0eU_7wAEs7z4M_TDNSXTcZJhlfwA=w538-h955-no)
You want the CA Cycleworks one with no pipe.
Mystery solved!
But I want to first thank everyone involved for your help. Without you guys and this community I wouldn't have know how to diagnose this. It was really a learning experience.
I pull3d the assembly back out and rigged a simple flow test with the pump and the old fuel filter and the new Ducati filter. I noticed the Ducati filter flowed less water! I can't believe it was the new Ducati fuel filter! !
Admittedly, I bought this filter off of eBay from a highly rated seller to save a few bucks. Never thought a fuel filter could be bad....
So the whole point of me replacing the fuel filter because I was having problems at high RPMS and full throttle. Unfortunately that wasn't resolved. So I'll be back posting in my other thread....*sigh
I replied to your question on my thread, but thought I'd post here too for everyone's benefit:
See this thread here where issues sound somewhat similar to yours: http://www.ducatimonster.org/forums/ducati-monster-s-models/318769-s4rs-took-running-like-crap-2.html (http://www.ducatimonster.org/forums/ducati-monster-s-models/318769-s4rs-took-running-like-crap-2.html)
Culprit turned out to be Crank Position Sensor ... hope that helps.
Cheers!
By the way, for the TPS, which we discussed how to test over on my thread (as a potentiometer, etc.) ... instead of fiddling with testing, if you're interested I can send you my old one. As I mentioned, I replaced mine with a new one from Ca-Cycleworks, but as it turned out the TPS was not the problem and there was probably nothing wrong with my old one. In fact, I have 2 extra TPS right now as I ordered yet another one from Aliexpress, super cheap (maybe $10 or so) but then I decided to go with the Ca-Cycleworks one because they test them on a special bench there. (I suspect what they do is that they have a supplier from China for them, but have invested in a testing machine to make sure they are good and they can guarantee them, which is why they charge $60 for an otherwise very inexpensive part.)
Anyway, as I mentioned, I can send you my old stock one - or if you prefer, I can send the new but untested Chinese one - so you test things out and see if there is an improvement.
Let me know.
Cheers!