2000redrocket
Pro
Posts: 1662
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posted May 03, 2008 11:09 AM
for my bike the "syndrome" was a extreem rich contition when giveing it lite throttle at say 2000 to 2600. it would fall to say -6.xx or so and go 10 to 1. so i leaned out the say -6 to -10 area and as it ran better leaning it out i'm carrying more vacume for the same transitions. and to a dofferent colum on the map. it all makes sence and works well. also had the real rich cruseing at 4000 to 5500 i have been helping that also. i went too lean on the area u are in going 4000 down a small grade at 15 to1 and had to go the other way a bit.
i notched my ecu by using a razerknife and just slowly working through the plastic.
  
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shiggsy
Expert Class
Posts: 128
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posted May 03, 2008 11:53 AM
My rings have worn. I was going to check the valve clearances and did a compression test first of all and got :
Cyl 1 2 3 4
psi 180 140 150 150
150psi is bottom of the range so I put a teaspoon of oil on each cylinder and re tested:
Cyl 1 2 3 4
psi 198 170 175 185
Rings have had it.
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2000redrocket
Pro
Posts: 1662
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posted May 03, 2008 12:15 PM
time for a 1270 kit.....
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shiggsy
Expert Class
Posts: 128
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posted June 15, 2008 08:35 AM
 Edited By: shiggsy on 15 Jun 2008 11:27
Found it.
The problem of my injectors suddenly switching, shutting down 3% as I opened the throttle and opening back up as I eased the throttle shut again was down to the TPS....but possibly not in the way you would imagine. My traditional view of the TPS was that it simply told the ECU how far the throttle was open, the more it opened, the higher the voltage the more fuel got added. Close it and its the opposite effect. The stock zero percent throttle baseline voltage for the TPS is 1.084 - 1.086 according to the manual and if you raise this you get extra fuel added everwyere. This doesn't appear to be entirely true.
Theres a line, specifically above TPS voltage 1.28 (typically about 7% throttle but this will move as the baseline moves) where this is true but at and below this line the opposite occurs and fuel gets taken away. The upshot of this is if you raise the TPS baseline (rotate clockwise) you simultaineously richen the AFR above this line and lean it out below effectively bringing the AFR either side of this line back into alignment. If you lower the TPS (rotate anticlock) the AFR below this line richens and above it leans out effectively moving away from each other creating an sudden AFR gap.
As I said above sotck TPS voltage is 1.085, but this is according to Edition 1 of the manual, I have Edition 3 and instead of quoting a specific voltage it specifies a formula based on input voltage which for me gives a base TPS voltage of 1.067, widening the AFR gap. This certainly fitted with the problem I was seeing and feeling.
The bottom line is the TPS, above this are the injectors,
So you can see as I open the throttle the injectors open until I cross over the 1.128 volts line and the injectors suddenly shut off 3%., remaining there until i ease the throttle back below that line and the injectors open up again.
When I realised this was what might be happening I logged two journeys one with the TPS set very low at 1.040v to create a big discrepency and one with the TPS set very high at 1.200v to close the gap and give a uniform reading. The results shown below support this.
I hasten to add ths is real world street riding, my daily commute route actually so there is no high end rev range featured here.
TPS 1.040, big AFR gap. You can clearly see the line is at 7%-8% with some cells having a +2 point AFR change. No wonder it was surging.
TPS 1.200, uniform AFR. No line.
The 1.040 run felt horrible, lots of surging. The 1.200 run felt very good at minimal throttle but not so good on an open road or motorway but there was no injector switching going on at all. I did some more runs at 1.175, 1.150 and 1.125. The 1.150 felt pretty good and at 1.125 the switching was just becoming feelable (it was certainy obvious on the realtime AFR gauge). So it seems to me my optimum base line is somewhere between 1.125 and 1.150.
This is the 1.125 run, you can see the seperation appearing at 5%-6%.
Two things about this caught my attention, one was remebring the first time I checked my TPS setting years and years ago, it was 1.126 and I reset it to 1.085. Perhaps I should have paid attention the bit where it says not to screw around with this. I also changed jobs 6 months ago and my fuel consumption for my new commute dropped to about 35mpg at best. During the course of this testing I had to fill up and my fuel consumption was back up to 40mpg. On my previous commute I spent a a greater amount of time on the motorway, so I was in the lean section more. My new commute means I spent more time in the rich area.
I guess this also means it would also be feasible to rig up a simple 'Economy Cruise switch'. So you could have a rich or stock base map but if you have a long motorway cruise to do just use a switch attached to the TPS that will reduce the voltage into the ECU leaning out that area?
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2000redrocket
Pro
Posts: 1662
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posted June 15, 2008 06:26 PM
very cool. are you happy with where you are keeping it at? sounds better. i think i am going to check my tps idle voltage. problem is as we all know when you move the idel adjustment you move the tps voltage and i am sure my idle screw is not where the factory had it.
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