Why Won't it start

[dlaing]

I'm still amazed at the difference in the Sport's running with the new battery. Stronger throught he rev range, higher idle.

 

Now I've noticed it's running richer ( higher TPS voltage?) and the fuel lght comes on MUCH sooner and much more brightly.

80319[/snapback]

 

An interesting thought.

I have the Electrex voltage regulator on my bike, and it produces very different voltage at various rpms. I did not notice a difference, but I did think about that possibility.

Perhaps your performance improvement is more related to getting a better ground after swapping the battery

But I suppose a bad battery could give you one less volt, which might shift your ECU map cells over one position, leanward.

[docc]

If this is true it is odd and should give cause for concern. With engine running, the battery OCV shouldn't affect unregulated voltage at the alternator, and provided the battery isn't such a short circuit that the generator output is pulled down (and if it was the battery would be fried dry) the charging regulation and secondary signal supply regulation within the ECU should hold the sensor voltages stable. Hence I can't see how fitting a new battery could affect mixture, fuel consumption or the appearance of the idiot lights if the electrical system was healthy.

80324[/snapback]

 

I certainly agree. If it were just the sense of 'stronger running' I'd say it was my wishful thinking. While the old battery kept a steady 12.7v the new Hawker is 12.84 v. Yet the regulator should level this off to its presets.

 

Here again, the tach is about 300 rpm higher at idle, fuel economy dropped about 2 mpg, and the fuel light came on at 4.3 gallons instead of 4.6.

 

No huge differences but enough to suggest a significant change. I did change the relays from Bosch to GEI as well but after I noticed the rpm increase.

 

I'll have to go into the TPS and see if it's throwing a higher mV than when it was last set.

[luhbo]

Normaly bad batteries show a higher internal resistance than good new ones, so if ever than the voltage at the clamps should be higher with bad batteries than with good ones. IMHO

 

The TPS sees approx. 5 V, produced by an internal V-regulator in the ECU. So it should also make no difference whether you have 11 or 13 V at the clamps.

 

What could be affected is indeed the mixture, because of the relation of injector opening/closing time to injection time. With lower voltages and especially at higher RPM your mixture could become leaner, as the nozzles open and close slower.

 

Hubert

[dlaing]

The TPS sees approx. 5 V, produced by an internal V-regulator in the ECU. So it should also make no difference whether you have 11 or 13 V at the clamps.

80598[/snapback]

On the Carl Allison, this old tractor, Will Creedon TPS instructions, they recommend setting with the engine running(mostly on the left cylinder).

I always presumed this was to produce more volts at the clamps.

I had trouble getting mine to idle running on the left cylinder, so I just measured with igniiton on and engine off.(maybe that is what I am doing wrong....)

 

What could be affected is indeed the mixture, because of the relation of injector opening/closing time to injection time. With lower voltages and especially at higher RPM your mixture could become leaner, as the nozzles open and close slower.

80598[/snapback]

Good point!