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Old 11-29-2012, 01:06 PM   #16
stever975
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Spraying the IAC seems to have helped the stalling but not eliminated it. Is that plausible? Seems to be screwing in and out OK anyway.
As I've mentioned before, if you don't have the P0505 DTC set (CEL isn't on), then the IAC isn't the problem.

The IAC motor is only used for idle control when the bike isn't moving and the throttle plates are closed (TPS < 1%). If the ECM can't control idle using the IAC, the P0505 DTC will be set and the CEL will illuminate.

If the bike stalls and there's no DTCs set, then the problem is most likely a spark plug or fuel flow issue (injectors, fuel pump, or fuel filter).
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Old 11-29-2012, 01:11 PM   #17
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Originally Posted by stever975 View Post
As I've mentioned before, if you don't have the P0505 DTC set (CEL isn't on), then the IAC isn't the problem.

The IAC motor is only used for idle control when the bike isn't moving and the throttle plates are closed (TPS < 1%). If the ECM can't control idle using the IAC, the P0505 DTC will be set and the CEL will illuminate.

If the bike stalls and there's no DTCs set, then the problem is most likely a spark plug or fuel flow issue (injectors, fuel pump, or fuel filter).
Yes, that's what the thread is about. My feeling is the fuel pressure is down, although it is possible there is an air leak on the inlet side. Unfortunately I have no reasonably easy way to test it, so I will get everything I can sort sorted first.
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Old 11-29-2012, 01:37 PM   #18
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Yes, that's what the thread is about. My feeling is the fuel pressure is down, although it is possible there is an air leak on the inlet side. Unfortunately I have no reasonably easy way to test it, so I will get everything I can sort sorted first.
An air leak below the throttle plates would cause the engine to idle high. The ECM would try to compensate by moving the IAC pintle in until it closed completely without reaching the idle set point. You'd then see the P0505 DTC.

I doubt you have an air leak but the standard procedure for checking this is to start the engine and direct a small jet of propane to the region where you suspect a leak. The engine idle will change if propane can enter the intake tract.
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Old 11-29-2012, 01:46 PM   #19
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An air leak below the throttle plates would cause the engine to idle high. The ECM would try to compensate by moving the IAC pintle in until it closed completely without reaching the idle set point. You'd then see the P0505 DTC.

I doubt you have an air leak but the standard procedure for checking this is to start the engine and direct a small jet of propane to the region where you suspect a leak. The engine idle will change if propane can enter the intake tract.
I chucked easy start at it. No obvious signs of anything. Seems to me the IAC would attempt to compensate for a small air leak and the results would be unpredictable.

But I think we both agree that low fuel pressure is the most likely problem. It only stalls immediately after being trashed, which to me implies the fuel pressure drops and then recovers.

If I can't successfully map it with this new base map, then I think I will call it case closed and buy a suitable pressure tester. However there is zero chance of managing that in Portugal, and I'm not in the Uk until Feb 3rd. So, even though it is top of the list of probabilities, it is the last thing to test.

So far I have changed the base map to a Harley one, fixed a dodgy connector to the Twin Scan, and sprayed the IAC. I've successfully mapped the mid range, tomorrow, with luck, now I am happy the whole map is not dangerously lean, I'll do some WOT mapping and see if I can get suitable AFR ratios. If not, I call low fuel pressure.
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Arnotts, D&D, SEPST, custom paint or all chrome according to mood, GRC seat, wave rotors, Muscle wheels, Burleigh bars, V-Gauge, assorted pretty bits.



2007 VRSC-AW (Fun).
2007 KTM 990 Adventure (Off Road and Touring).
2006 Triumph Daytona T955i (Evil).
2009 Fatboy (Heavily Tarted Up Show Pony).
2011 Bonneville (On long term loan).
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Old 11-29-2012, 06:04 PM   #20
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Louis, with the Race Tuner you can copy and paste maps into excel files and save them. No need to throw away a map. Just remember to label each map and maybe use one spreadsheet of a workbook for notes so you can remember what you did later.
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Old 11-30-2012, 02:08 AM   #21
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Louis, with the Race Tuner you can copy and paste maps into excel files and save them. No need to throw away a map. Just remember to label each map and maybe use one spreadsheet of a workbook for notes so you can remember what you did later.
Phil, with the SEPST, once you have the map in front of you, you can save it directly, no cutting and pasting required. But the SEPST cannot (or more accurately is designed not to, because Harley are Corporate Evil personified) read maps from the bike. Ergo your first unavoidable step when you use a SEPST is to lose whatever map is currently on the bike.
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Arnotts, D&D, SEPST, custom paint or all chrome according to mood, GRC seat, wave rotors, Muscle wheels, Burleigh bars, V-Gauge, assorted pretty bits.



2007 VRSC-AW (Fun).
2007 KTM 990 Adventure (Off Road and Touring).
2006 Triumph Daytona T955i (Evil).
2009 Fatboy (Heavily Tarted Up Show Pony).
2011 Bonneville (On long term loan).
1978 Triumph Bonneville Based Racer (Needs A Rebuild)
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Old 12-10-2012, 05:21 AM   #22
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Fuel pressure seems OK, I'm able to map it with no silly numbers.

Bloody thing is still stalls though. No codes.

I do remember last time I had the airbox off the gasket tore, and this being Portugal and a replacement gasket being a month's lost riding away, I bodged it with silicon. Could a small gasket tear be it? Might be around the IAC...

Note - I don't care about the stalling, it doesn't bother me. I know how to ride with no idle. I'm only interested in it as a symptom of something serious.
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http://www.flickr.com/photos/acam
http://www.thegentlemansnapper.co.uk

Arnotts, D&D, SEPST, custom paint or all chrome according to mood, GRC seat, wave rotors, Muscle wheels, Burleigh bars, V-Gauge, assorted pretty bits.



2007 VRSC-AW (Fun).
2007 KTM 990 Adventure (Off Road and Touring).
2006 Triumph Daytona T955i (Evil).
2009 Fatboy (Heavily Tarted Up Show Pony).
2011 Bonneville (On long term loan).
1978 Triumph Bonneville Based Racer (Needs A Rebuild)
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