wikkaco0

In addition to the issues with the non vtec calibrations (handful of non vtec cars have had their engines cut out at high rpm without explanation, I seem to have the only working one in Montreal now after a vtec headswap)... it appears the base calibrations for the D17 also do not work in cold weather.

The issue is cold cranking when coolant temperature is about -10 degrees celcius (or 14 fahrenheit) or colder. Leave the car outside when its about -15 celcius and when I try to start the engine just turns over at a nice 180rpm but will not start, at most it will fire once then return to 180rpm.

I suspect the problem pertains to the cranking injector pulse widths in relation to engine coolant temperature. This can be found in the Parameters windows under the Fuel Trim tab in Kmanager. Unfortunately it is very difficult to tune this because I have one or two attempts a day (provided the weather is cold enough) to try new values. I have set my overall cranking fuel trim to 0% and have found the correct values for -1 degree celcius and above in the Cranking base injector pulse table. They are as follows

ECT in degrees C..........-31......-15....-1.....20.....41.....61.....82.....90
Injector pulse in ms........?.........?......65.....30.....20.....15 .....8.......7

I know a linear trend is belived to be ideal and I realize these values are far from linear, but they seem to work down to about -5 degrees celcius out after having left the car out for 24 hours.

Anybody else have this issue or seen something like this? My car is in my garage warming up and wired to a battery charger now. This car is usually stored in winter and has had this issue since I installed the kpro.

Experienced tuners, your help would be greatly appreciated. Guessing values is really starting to get time consuming.

bomerman19

iTrader: (1)

Yeah I have had the cold starting problem before myself it used to be really bad with my stage 2 cam and shitty tempest map. it is not so bad now only very rarely does it ever do it to me and the temp has to drop below 20 degrees F which is probably a little less than -5 degrees celcius.

It is definitely one of the harder things to tune on the car and takes a little bit of practice, especially since most tuners don't tune for cold cranking cause it can be hard to replicate the circumstances.

So here are my questions,
what size injectors are you running?
Stock cam or something different?
What was your cranking fuel trim originally set at before you started playing with it?
and what mods do you have on the car to accompany the k-pro ie IHE turbo?

I know it's a lot questions but all those things can make a big difference in the cold cranking.

wikkaco0

So my suspicions were right, I'm not the only person that is dealing with this. So to answer your questions I have stock D17 injectors (84000km on them, I don't drive it much). All the bolt ons... intake, header, exhaust, no catalytic converter. Right now I have a stage 2 crower n/a cam.

The calibration overall has been tuned quite well on the street. Spent quite alot of time perfecting it. So once the car is running everything is great. It's just getting it started.

Also have a PLX wideband air fuel sensor. I'm not sure if the readings are reliable during cranking because it is being powered by the cars' electrical system. I'll try and wire it up to an external DC source when I have time.

With a 100% stock complete D17A1 with kpro, I also had the same issues. Well it was worse, I wouldn't recommend anybody use a kpro on a nonvtec d17 no matter the setup.

My cranking fuel trim was originally set to what it was in the stage2 base calibration included with kmanager. I started tuning just the cranking fuel trim and came to realize that at -1 celcius, +50% trim worked very well. But at other temperatures it was less than ideal. So I looked at the injector pulse lenght in my datalogs and started editing the coolant temperature based cranking fuel table accordingly, all the while setting the overall cranking trim back to 0%.

Thanks for your input! With any luck we'll have this solved by the end of winter.

emjay

iTrader: (2)

stage 2 turbo cam//750cc injec
kpro
-25 degrees celcius was the only time my car didn't start .. which was ON newyrs it was so cold .. i live in toronto and my car is parked outside average 3-6 hours a day and fires rite up except for newyrs night when it was out for 7 hours str8 -30deg. or more that nite with windchill

katzenjammer84

This might sound like a temporary solution, but it's an easy one: buy an OEM Honda block heater

Coolant/oil will always be warm on cold days.

bomerman19

iTrader: (1)

wide bands do not usually run properly during cranking cause that is when they are cycling through the test cycle. So wide band reading's are kinda pointless for you cold cranking settings.

Also I would not bump the cranking fuel trim up to 50% most i would go is probably 20% the problem with with going that high is you dump a lot of fuel and flood the motor and then It won't start cause it's flooded.

Let me look at the different stage 2 maps that I have and see if I can come up with some better settings for you to run. umm I have a lot to do to night so I am not going to get a chance to look at my maps till late tonight or possibly tomorrow, so bear with.

wikkaco0

Hondatas base calibration for the d17 with crower stage 2 NA cam has a cranking fuel trim of +20%.

Assuming I wire my wideband controller to an external 12 volt DC source independant of the car, will the readings during cranking be accuriate enough to tell if I need more or less fuel? After I have heated up the sensor to operating temperature of course.

bomerman19

iTrader: (1)

that map throws a lot of fuel at the car bump your cranking fuel trim down to 3 to 5% if you are still having trouble pm me your e-mail address and I will send you a new base map that should help you out a lot. Right the moment my guess is that you are dumping so much fuel during cranking that you can smell it.

bomerman19

iTrader: (1)

Sent you a Special Base map should run really good forgot to mention you should get better gas mileage with this map also.

don't have internet at my house right the moment so it is taking me some time to respond sorry.

emjay

iTrader: (2)

i have a stage 2 turbo cam and kpro and just checked with my tuner .. my cranking fuel trip is 8% which works best

bomerman19

iTrader: (1)

yeah but what size injectors are you running?

That makes a big difference cause it really comes down to the injector pulse and the actual map.

I'm guessing you are running significantly bigger injectors then stock so your tuner probably has your injector pulse or map set real lean so it needs to have alot of extra fuel dumped to get it running. the stock stage 2 NA base map throws so much fuel at the car that it floods it almost every time in the cold. I actaully have had to go to negative percent for cold cranking on the original hondata base map

skipbarber

iTrader: (34)

holy ****. i just posted about this over on the hondata forum. my car has been doing this since last year. I panic in the cold if i dont have someone to help me push start the car. lol. Ive been trying to figure out a solution to this problem for a long time now. let me know what you guys come up with...

Rufus

iTrader: (17)

I never had this problem... then again, I live in Arizona.

wikkaco0

I'm still working on it. Nothing good to report yet...

It's been about -25 celcius here for the last week. Definately a fuel related problem though.

It's been like this for me for almost two years. Doesn't matter if the car is stock or has a built motor. Same issue persists regardless of the calibration chosen.

Anybody know how to tell if a car is flooding or lacking fuel during cranking?

supafil25

iTrader: (2)

i read on another forum that you need to lean out the fuel for the car to start in the cold.

skipbarber

iTrader: (34)

well, i know in my case it's clearly flooding, because when it refuses to start and i push start it, i get a huge black cloud of smoke followed by a very pungent unburned fuel smell. Your theory on using a separate DC power source for a wideband wont work simply because there isnt a sufficient flow of exhaust gases passing by the sensor for it to make an accurate reading.

bomerman19

iTrader: (1)

I'll see about talking to jeff evans tomorrow and see what he has to say on the matter I know he used to tune for cold cranking on race cars but it meant leaving the car with him for a couple of days so it could sit out in the cold which isn't really an option for me since I live so far away but he might have some better settings for the injector pulse

skipbarber

iTrader: (34)

i got mine to start right up today. my settings right now for -24, 5, 31 are 68ms, 50ms 34ms. 34ms might be too short, but my cranking fuel trim is set to -10%. My plan is to keep playing with the numbers until i find something that works.

bomerman19

iTrader: (1)

I'm only having problems when my engine gets cold soaked and gets dropped down to 5 or lower

aspech

I just installed my krpo lastnight. Its pretty cold in chicago, but i believe i'm having the same problem. I'm running the 01-03 Vtec base map. I have a D17A1 Block w/ a A2 head. Stock injectors stock cam. It wouldn't start up right away. When it did, i rev it and it cuts off at about 3000RPM's. 1st gear wont go above 3000RPMS with out the fuel cutting. (i can hear the intake sucking and not going anywhere). 2nd gears fine until about 5-6000RPMs. 3rd/4th gear cuts out if i give it to much gas and 5th gear cuts out if i give it to much gas or go over 50 degree. Now my frist thought was my timing was slightly off but now i'm kind of clueless. Is this pretty much the same problem. Oh, and my car would warm up, rad fan on, and it'd still have the same problem.

filipinop1405

iTrader: (6)

when you say stock cam you talking about the camshaft or cam gear? cuz you do know that you need the modified cam gear that hondata sells or there dealers sell? well just thought i would put that out before someone else asks.

skipbarber

iTrader: (34)

thats not the same problem at all. this thread is about Kpro'ed d17's that dont start at all when cold soaked. datalog your car and post it. youve got something screwy. did you do the vtec head and kpro at the same time?

aspech

stock camshaft hondata modified cam gear. going to try somethings now ill datalog also thanks

aspech

Getting no error codes fuel stats is saying error on the display everyyhing else is fine

skipbarber

iTrader: (34)

you may have loaded the wrong calibration. does it show o2 voltage? if so what is it and does it fluctuate?

bomerman19

iTrader: (1)

were you sitting still when you rev the car cause it sounds like you have your launch limiter engaged

aspech

driving and sitting.

launch control is disabled.

aspech

http://www.7thgenhonda.com/forum/sho...?t=9631&page=5

wikkaco0

I had a very similar problem with a full D17A1 stock setup with Kpro. Issue was resolved when I installed the VTEC head and updated the calibration.

The engine was very sensitive to cutting out when it was just started up too.

Regardless the cold starting issue seems to be something completely different. Anybody have any other suggestions or news for us?

emjay

iTrader: (2)

im running 750cc injectors ... and stil having problem with the cold start ... what should i do .. should i set my crank to -10% .. do i play with the pulse rate and stuff too?