S300 + Skunk2 intake mani - car stalls cold weather

[jun1or]

Cliff notes:

1.) Skunk2 Mani on my GSR causes crap starts in cold weather, suggestions? (READ #2)
2.) Hondata S300 tuned to around 14 AFR at idle, should I go richer or (READ #3)
3.) Should I adjust Smanager Fuel Compensation idle and light engine load table to > 10% for temps around 5 give or take?

I live in Wisconsin. Recently it's been about 5 -15 degrees in the morning. My car will not start without me pressing the gas for 5-10 seconds. This is due to 2 things from what I can suspect. Skunk2 intake mani and idle tuning on Hondata S300.

I've installed the skunk2 intake manifold which eliminates the throttle body warming. I have also recently(5 months ago) installed a Hondata S300 + wideband on my mostly stock GSR. I've adjusted the maps to be around 14 AFR at idle. I believe this is a bit lean for idle. I've tuned the maps gradually over the past 3 months but I've adjusted idle from 11 to 14 (rather big jump) in 45 degree weather with no major idle changes. Maps look good regardless according to wideband, no major problem areas.

I know what most will say... Well if 14 AFR is too lean, then go richer and see what happens. Cool, I'll try that regardless of this post.

My real quest is for someone with an S300 in cold weather to tell me to change either
a.) low speed map at idle for 12ish AFR or
b.) S300 Smanager Fuel compensation table at idle and light engine load to greater than 6.9% at 7 degrees F, which is factory setting. I'll log S.trim settings to see if ecu is compensating for lean conditions in closed loop and post results on this thread regardless, or
c.) other.

Thanks for your input.

Mike

[jun1or]

When reporting any s300 problems, please include:

- the calibration (as an attachment)
attached

- a datalog of a problem (as an attachment)
I will try and log tomorrow (today) as it's f-cking cold with 14 inches of snow.

- what sort of vehicle you have
91 CRX, USDM B18C1

- what sort of ECU you are using
P06 S300

- anything about the car which has been modified from stock which may affect the ECU (don't include what sort of rims you have nor stereo etc).
Crower stg1 cams, mainly stock.

- a specific description of the problem
see post #1

Again, thanks.

Mike

[jun1or]

(I feel like a dork responding to my own thread at 12am... twice.)

I realize that a datalog will help incredibly. I will do that in about 12 hours. Thanks again.

Mike

[jun1or]

It's about 5 degrees outside here.

I started it a few times and it fired up for 3 seconds and died (as expected), short datalog, next post.

Then I stopped the log and started a second log to which I pressed the gas when starting and got it going just fine... shut it off, datalogged a successful (lukewarm per se) 30 second datalog, next post.

I noticed 1% tps in the datalog even though my foot is off it. I recently calibrated this too. I don't suspect this is the problem but who knows.

Thanks again.

Mike

[jun1or]

Two datalogs comparing:

A coldstart, 5 degree weather, cranked three times, all failed.

vs.

A lukewarm start (warmed engine for 2 mins in 5 degree weather, shutoff) then 30 second datalog with successful start.


Datalogs attached. Notice in the Temp Comp graph view, you'll see that in the cold start failure I have 32% ECT.c and at about 1300rpm when cranking and in lukewarm successful start I have only 17% ECT.c value. Could this be a clue? I'm learning here... Help me out.

Remember I did lean out my idle area of map a bit recently. This might be a waste of time as I'm answering my own question?

I have also not adjusted Cold Start Fuel Trim value as per documentation:



Cold Start Fuel Trim:

Post Start Fuel Adjustment - alters the amount of fuel added immediately after starting the engine. This extra post start fuel is normally slowly reduced to no extra fuel over the period of 10-30 seconds. Changing the post start fuel adjustment will alter the amount of fuel and also the enrichment time period



Mike

[thething96]

I'm not using s300, but I had the same issue(almost gone!). Do you have a wideband hooked up? You might want to check your cranking afr's when really cold. My car would start good at about 40 degree weather. In from Chicago, so it also got pretty cold. I have an AEM wideband, and noticed that when I was cranking the car, afr's were at 10.00. And idle afr's at 5 degree weather was also around 10.50. Adjusting that can help, and also adjusting cold start ignition. Having the throttle body bypass could help as well. Last thing, what % cycle do you have your idle air control valve working at?

[jun1or]

I'm not using s300, but I had the same issue(almost gone!). Do you have a wideband hooked up? You might want to check your cranking afr's when really cold. My car would start good at about 40 degree weather. In from Chicago, so it also got pretty cold. I have an AEM wideband, and noticed that when I was cranking the car, afr's were at 10.00. And idle afr's at 5 degree weather was also around 10.50. Adjusting that can help, and also adjusting cold start ignition. Having the throttle body bypass could help as well. Last thing, what % cycle do you have your idle air control valve working at?

I've moved the idle slider to the left a bit (this wouldn't make sense if you don't have S300 as I'm not being technical am I?).

I do have an AEM wideband also. I bet I'm much leaner. Appreciate the comments.

Mike

[thething96]

I don't have hondata, but running something similar :twisted: . With the AEM wideband, before crancking the car, let the koef for about 20 seconds. After that, the afr readings will be correct. I'm thinking you're running real rich or real lean, only wide band(or your nose if it stinks like fuel), will tell.