| Author |
Message |
    
Id073897
| | Posted on Tuesday, November 27, 2007 - 05:55 am: | 
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TPS voltage on the unmodified TPS on my bike was .633v at closed throttle. From my experience from working on late model Mustangs, baseline TPS voltage was to be set .980v at closed throttle. [...]
The ECM knows nothing about voltages.
What do you think the TPS reset is good for? If the closed throttle TPS reading would be too low, the ECM would raise a trouble code.
Regards,
Gunter |
Heyfred
| | Posted on Tuesday, November 27, 2007 - 12:26 pm: |
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If the closed throttle TPS reading would be too low, the ECM would raise a trouble code.
no
http://fordfuelinjection.com/?p=30
(Message edited by Heyfred on November 27, 2007) |
Id073897
| | Posted on Tuesday, November 27, 2007 - 02:27 pm: |
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I don't care how Ford ECUs handle this situation and I'm pretty sure Ford doesn't worry about Buell ECMs either. These act as described.
Regards,
Gunter |
Heyfred
| | Posted on Tuesday, November 27, 2007 - 02:54 pm: |
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Show me how it works. |
Id073897
| | Posted on Tuesday, November 27, 2007 - 04:10 pm: |
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No problem.
Watch TPS 8bit vs. TPS Volt. or TPS ADC in EcmSpy and try several different positions when resetting the TPS. You will allways see a fully closed throttle at zero TPS 8bit, independent from the voltage applied.
The mininum allowed TPS ADC reading is usually set to 100 (of 1024), which then represents about a bit less 0.5 volts. Just cut the wire, thus less than the required voltage is applied and the ECM will flash the CEL after a few seconds. (BTW: how to detect a broken wire, if no low limit exists? Did you ever ask Ford this question?)
Regards,
Gunter |
Stedee
| | Posted on Tuesday, November 27, 2007 - 07:52 pm: |
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Heyfred, what do you think now? I recently found your post about manually moving the TPS and was considering trying it. My TPS volts closed is .740 volt. This is within the range mentioned in the manual, but was going to give it a try anyhow. The svc. manual gives little about theory, but it does say that the TPS is used as a load input.
I have not seen or used the scantool/software for this system and do not understand how it works.
One would think that if it (TPS)is the load input, (which is poor), raising the return voltage from v-ref would make the ECM respond by a longer pulse-width, and richening the system slightly.
Heck, the TPS and wiring connectors even look like Ford parts. They use a ground, 5-volt v-ref, and a return signal voltage.
So, the O2 as I have read in the manual switches below and above .5 volts and I assume is considered a Feedback to let the ECM know how it is doing and make adjustments.
We talk of fuel trim tables too, and how we can use them to help diagnose driveability concerns by looking at the values the ECM is using.
Would be nice to have a good overview of how these fuel systems work. They seem so primitive compared to modern automotive systems.
I hope to be able to end up with this thing running smoother in light throttle cruise mode.
My exhaust is at K-D now, Kevin said the mod would help.
Now looking at some type of mod to get the breather hoses out of the air filter base so they aren't spewing crap onto the IAT sensor too.
So what happens when a TPS reset is done? Can anyone explain? |
Id073897
| | Posted on Wednesday, November 28, 2007 - 12:38 am: |
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As said before the 10bit voltage digitizer gives a value between 0 and 1024, representing 0 to 5 volts. The TP signal used for selecting a cell in the fuel map is only 8 bit wide (0-255) and the TPS reset maps this range onto the full voltage range. After the reset the closed position (which is usually set by backing off the idle adjuster and snap-shutting the throttle) is always 0 and the WOT position is always 255 in 8 bit resolution, regardless of the real voltages applied.
Nevertheless, if you don't know how sensors work, how ECUs work and how the calibrating software works, you should either learn it or keep your hands off the ECM. It's not a toy, it's a fully blown engine management unit. We identified more than 200 variables and maps in the ECM's storage, which might or might not impact driveability.
I would also recommend reading the EcmSpy threads in the UKBEG forum to learn how the ECM works and might be adapted to your bike's setup.
Regards,
Gunter |
Heyfred
| | Posted on Wednesday, November 28, 2007 - 03:10 am: |
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Would be nice to have a good overview of how these fuel systems work.
http://www.efilive.com/
I took the beginning and advanced classes.
They seem so primitive compared to modern automotive systems.
Yes
look like Ford parts
They are |
Id073897
| | Posted on Wednesday, November 28, 2007 - 03:38 am: |
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I took the beginning and advanced classes.
Great. Then you might consider contributing to the EcmSpy project and help to improve our software or extend the tuning capabilities of the ECM.
Regards,
Gunter |
Reepicheep
| | Posted on Wednesday, November 28, 2007 - 08:33 am: |
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Good to see you posting here Gunter, thanks for the information, and the work on ECM spy... great stuff! |
Sycojomo
| | Posted on Monday, December 03, 2007 - 02:46 pm: |
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1300 miles later, including two 500+ mile trips, my bike is running beautifully.
Okay, I thought I posted something before thanksgiving, but must've forgotten to hit that final "post" button or something. Anyway, here's my update.
I took the bike and had Gary and Brad at Smoky Mountain Harley-Davidson in Maryville, TN ride it the weekend before thanksgiving, and they both really liked it. Gary seemed to think the primary chain might have some play, so I mentioned this to the service department and since I picked the bike back up that Saturday evening, it has been running great. So it would seem my problem was mechanical and not electrical.
Since I picked the bike up, I have run the Dragon's Tail on my way to and from Wilmington, NC, and have thoroughly enjoyed the experience.
Anyway, if you are ever passing through Maryville, TN I recommend their service department. Also, I can't thank Gary and Brad enough for their help.
Now about those headlights... (I know, different thread)
Cheers, Josiah |
Buzzie
| | Posted on Wednesday, December 05, 2007 - 03:08 pm: |
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Hey Gang...not sure if this is the right forum...my first time here...Just a very important statement about all xb models..Before reseting or playing with the tps and the afv....Make sure you have the correct throttle cable adjustment. If your throttle cable it too tight..many times they are from factory...you will be lying to the ecm about having a fully closed throttle plate. makes a hell of a lot of difference. hope this basic statement helps someone |
Bombardier
| | Posted on Monday, December 10, 2007 - 12:27 am: |
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Gunter,
Do you have an opinion about using a 4 wire wide band O2 sensor in place of the std narrow band one wire sensor? |
Loucksgl
| | Posted on Thursday, December 13, 2007 - 09:11 am: |
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Sycojomo -- Glad to hear your bike is doing well. Mine also is running as great as any I have ever owned. I'm the "surge king." Running el fino. As for ECM and electronic toying; My motto is let it be if ya don't understand it. Book keepers don't do brain surgery. Later |
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