drewlee

I installed the dsm 450's the other day so I could get a head start on my turbo project.
So I install the injectors and set the settings to -40 across the board. I start it up and my idle is about 1500 rpms at cold start and when it warms up it drops down to about 900-1000 rpms. It flucuates from there going between 900-1000 rpms. At this setting(-40) the car bogs a little bit and hesitates, so I put the setting to about 38 and It didnt bog or hesitate but the idle was about at 1200 rpms with a little fluctuating. I was wondering what you guys thought could be the problem.
All my setting are correct and this is on a 92 civic si with a lsvtec.
If I drive the car it drives great and pulls hard like it did when it had the stock 240's in it.
Let me know if you guys got any ideas.
thanks
drew-

USDM 4G VTEC

my settings are
-37 1-2.5k
-36 2.5k-3.5
-35 to 4k
-34 4.5k
-33 after 5k

fsp31

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by USDM 4G VTEC &raquo;</TD></TR><TR><TD CLASS="quote">my settings are
-37 1-2.5k
-36 2.5k-3.5
-35 to 4k
-34 4.5k
-33 after 5k
</TD></TR></TABLE>

That is a LOT richer than I'm running. I run -40 up to 4000 rpm's, then -38 to redline. The only time I have experienced idling issues is when it is below 40 degrees outside. Then the car idles rather high and erratically. On warm days the car idles perfectly. I believe it is related to the IAC valve and the fact that the AFC is sending such a "high" negative MAP signal to the ecu. It hasn't been enough of an issue for me to bother with though.

drewlee

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fsp31 &raquo;</TD></TR><TR><TD CLASS="quote">

That is a LOT richer than I'm running. I run -40 up to 4000 rpm's, then -38 to redline. The only time I have experienced idling issues is when it is below 40 degrees outside. Then the car idles rather high and erratically. On warm days the car idles perfectly. I believe it is related to the IAC valve and the fact that the AFC is sending such a "high" negative MAP signal to the ecu. It hasn't been enough of an issue for me to bother with though.</TD></TR></TABLE>
So you are saying that you think my IACV is bad?

fsp31

No. Is it chilly where you're at right now? I'm thinking the action of the IACV can be a little weird with the hack. After all, we are telling the ECU that manifold pressure is 40% less than reality. This issue is also related to the "jerky" feeling when you let off the gas. When the throttle closes, the ECU cuts fuel to the injectors... The IACV is also functioning under the same "weird" set of parameters forced on it by the hack, so I wouldn't be surprised if idle is affected occasionally. For my car it's cold air that causes it.

Sorry, I wish I had a fix. Just speculating as to the cause...

drewlee

ok I get what you are saying. It is about in the 70's where I am at.