Hey Guys,

 

Been following this forum for sometime and recently took the plunge of getting a Powervision for my 2014 Sportster. I 've got SE slip-ons and an Arlen Ness Big Sucker. I ran the canned appropiate tune from the PV and did an autotune following that. Bike runs great (better response, no decel popping). However at ignition when I start her up, I sometimes get a pop, or it may fail to start on the first turnover, something that never happened before. 

 

Are there any settings I can change under quicktune to help with starting the bike a little smoother? Do I need to take it in for a proper dyno tune? If so does anyone know of any good tuners with experience on PV here in Sydney? 

 

 

Try sending the same e-mail to dyno jet themselves and post their answer back on here.

They are a very helpfull bunch.

You dont have to dyno but it may help, or
Try running a few auto tunes.

Extract the stock tune into a pvt file, then do a compare the following with the stock vs modded tune

IAC warmup temps
idle RPM
Cranking fuel
Warmup enrichment

a wild disparity between the two will be the likely culprit, a delta compare between the maps will help spot it.

hope that helps.

Thanks Brash, very helpful. As its the turnover that causes the pop/cough, looks like the focus is on Cranking fuel, I'll do the compare tonight.

Response from Dynojet:
The startup area of the tune can be adjusted, you would need to use the WinPV software to do this. I would adjust the cranking fuel setting, found under Fuel. Increase the fuel values at the temperature you are having the problem, by 2 as a start. For example, ifthe value in the table is 34.8, change it to 36.8. Then test.

Hi,

Yeah good info Brash

Thanks
Robots

Hey Guys,

This is were it gets interesting, Dynojet are saying to increase cranking fuel by 2, however when I look at delta of new tune to original (pasted below) the delta's are positive in particular for lower temps, so shouldn't I be reducing cranking fuel mulitpliers?

 

hi,

so at this stage the dynojet map provided has higher values than the stock map? yes reduce if trying to get back to stock map numbers

the other things is from -16 to 30 degreeC the numbers should go more like 15, 13, 12, 10, 9 etc

does get confusing sometimes reading delta and which map is compare or active

thanks
robots

Hey Guys,

Created two tunes

1) dropped Cranking Fuel values down by 2 to 30Deg Celsius Temp.
2) Increased Cranking Fuel values up by 2 to 30Deg Celsius Temp.

Tried 1) bike made a definite pop - I shut it off straight away so engine was cold and tried 2) bike started smoothly!

Looks like problem may well be solved, it simply needed more cranking fuel.
COuld be as map is based on SE AC and I have a big sucker, not sure if has a higher air flow rate ...

Thanks all for your help!

Good to see it sorted.

I had a similar issue with my sporty, it actually caused a huge backfire in my new air filter and set it on fire haha.