Hey guys, hoping someone can give me some insight here.

If I get into boost for a period of time, like a 1st through 4th pull, or multiple back to back pulls, the AF ratio just plummets to below 10:1 afr (pegs guage rich) IN VACUUM/ PARTIAL THROTTLE, causing it to sputter occasionally. After a few minutes/ seconds depending on how long it was in boost, it returns to normal operating AF ratio suddenly, not gradually. The problem is NOT present at idle.

The problem is amplified when run in closed loop; however, it still happens running in open loop. When in closed loop, it takes a MUCH longer time to return back to normal operation.

This has been a problem ever since it's been boosted 26k miles ago. I do my own tuning and cannot for the life of me figure out why it's doing this.


Here's my setup:

d16y8 stock w/ ARP headstuds
Hondata s300
AEM wideband
TD04H turbo @ 14psi
DSM 450cc injectors

 

anyone? please? lol

 

Bump, need some ideas!

 

post a screen shot of your fuel and ignition maps.

 

Any abnormallities in the datalogs like sensors not reading right, or ECT or IAT very high??

 

subscribed

 

Please post the Cal and a datalog. this will make it easier to trace down a problem.

 

Exact same problem here... Boosted B18B. I am beginning to think it may be an issue with the stock FPR

 

OK, sorry it took me a while to get back to you-- I do not have a datalog of the condition; however, I will go out and get one here shortly.

ECT has never gotten over 204 degrees F --- not too sure about IAT. I suppose that's a factor we can look at. for now, these are the maps as well as the fuel parameters.

 

Just took the car out to recreate the issue; however, I wasn't able to.

It's <10 degrees F outside, and I couldn't get the ECT above 183F, and the IAT wouldn't budge over 50F--- even doing miles of back to back pulls in excess of 100mph--

So I figure i'm going to have to wait till a warmer day where the chances of the car getting heatsoaked are more likely.

 

Whats with the vac colums ,are they backwards or is that the way it is with the s300?

 

The labels are backwards, but it acts like it's going the correct way. Why I don't know.... but it works just fine. anyone else's like this? know why it's like this by default in s300?

 

You can go into options > settings > Units > and change Vacuum base units from absolute to atmospheric.

 

did you do a swap in the car from a nonvtec to vtec motor? did u wire in the vtec pressure switch? if not, try to jumper pins A4 & D6 on the ecu.

On a side note, i see you r running a Y8 motor. did u get it tuned? Your timing looks pretty high for a Y8 motor.

 

hrmm... what exactly does that do?


and for the timing-- I thought WOT was 30 degrees stock, so I figured that 15 degrees at 14psi (it's off by two psi due to this being a CO car-- high altitude so map reads off by 2psi) was pretty conservative...

so just a little bit more than 1 degree of timing pulled for each PSI. Motor runs strong, no pinging audible.

Please, correct me if i'm wrong--- perhaps I may have been misinformed.

 

No swap. Factory motor with 170k.

I tuned it myself.

 

It sets it so it reads atmospheric pressure as 0 the way you wanted it. Also, you can compenstate for your elevation if you would like...

 

I would love to compensate for the elevation... I think I found it, Do I just adjust the offset of the map sensor under the parameters window?

 

Sorry guys, we have gotten an influx of snow the last few days, and there is only more to come. I can't really take the civic out to test. I will update when the weather allows me to datalog the condition.

 

D16Y8 stock timing in VTEC and high rpms is around 19-20*. All the Y8 motors i have tuned needed timing around 12-14* (low boost ~10psi). 15* at 10-12psi might be fine, its just in your lower boost levels timing seems high. from 3400rpms and up and -27 to 2.5psi looks to be on the high side.

 

Interesting. I did some reading on turbod16 and the y8's timing. Claiming that it's 9 degrees off at the crank and 4.5 at the cam due to the cam sprocket if you run a p28 ecu due to the differentiation between the z6 and y8 Cam gears.

This could allocate why I haven't blown up. This would put me around from the last datalog at about 9* at 14psi because the datalog showed 18* right?

My question is, is that reallyoff? i synced the timing with a timing light matching up with hondata, so I figured the values I put in my maps were what the engine was seeing as well.

 

take it to a tuner before you damage the engine. there could be many variables tuning, air temps./ and or a mechanical issue. my recc. especially if u are not familiar with the s300

 

Pretty sure she's not going to blow up-- beaten on daily for a year and a half with 26k miles boosted and 170k on the untouched bottom end, I figure she would have gone already if something was very far off.

I'm fairly familiar with the s300, i'm just trying to pin down a few issues-- it's all about learning, and with a throw-away y8 stocker, what better way to learn?

I was able to re-create the issue yesterday, but my laptop died and i lost the datalog. Air temps don't seem to be an issue. When the rich condition occurs there is little to no variation there. ECT was at 180 degrees. Again, the only thing that seemed out of the ordinary was the AF ratio at 10-11 AFR in vacuum, then after a period of time it came back to normal.

I'll try to get a clean datalog for you guys. Sorry it's taking me forever-- End of the semester work for me.

 

How do you compensate for the elevation?

 

where is ur 02 sensor loacted in the exhaust stream, possibly flooding the o2 sensor with a rich mixture if to close to turbo.