OK. I have a 2000 Civic EX... OBD2 ver. 2, P2P ecu whatever you wanna call it. I have the afc hack w/ the dsm 450's on it working fine. My lo settings are -40 at idle, and -38 across the board and hi settings were dyno tuned. I just borrowed a friend's obd2 ver. 2 conversion harness to plug in a P28 I bought. Well I plug it in fire it up... car feels like it's going to stall. I richen it up to about -32 and it stabilizes.... rev it up... seems fine. I turn the car off, then turn it back on, the car started up rough (similar to when the engine got flooded once when my fuel pump would stay on priming). Then after a while it stabilizes. I didn't get a chance to drive it since my friend was leaving. Is this normal? I didn't expect the maps in a p28 to be that different for idle than a p2p. Also, I'm running 3 day old ngk bcpr7es-11's gapped at 0.030.

 

I don't think it has anything to do with your tuning. Try unplugging your evap purge solenoid (the little black box on top of the fuel rail), it fixed all my idle and start-up problems when I converted to the P28.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">I don't think it has anything to do with your tuning. Try unplugging your evap purge solenoid (the little black box on top of the fuel rail), it fixed all my idle and start-up problems when I converted to the P28.</TD></TR></TABLE>

thanks man... i'll give that a try. dumb question but what exactly does the evap purge solenoid do?

 

Not exactly sure, but it is some type of emissions that OBDII uses, but not OBDI. It has something to do with the evap can that sucks up the gas vapors.

 

hrm still kinda funky idle . i'm gonna let it cool down, plug it up again and drive around for a while. drives totally fine just stumbles a lil on idle.

 

i tried the exact same thing.. with my p2p ecu i was running rich, but when i plugged in the p28 ecu it was running very lean. i richen up the setting and it was back to normal.

 

yah i noticed the car liked a lot richer settings... i guess time for a retune

 

are you tuning w/ reading from the a/f guage or the wideband? the a/f guage can throw off the correct value.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by @irborne &raquo;</TD></TR><TR><TD CLASS="quote">are you tuning w/ reading from the a/f guage or the wideband? the a/f guage can throw off the correct value.</TD></TR></TABLE>

neither really for right now. just trying to get it to idle straight lol. when i said i was going to tune it, i meant on the dyno. right now it runs good... a/f gauge looks ok and egt's look nice.

 

As an emmisions requirement, fuel tank vapors need to be trapped and later purged into the manifold to be burned. The EVAP Purge solenoid is what does this job. It is a pulse-width controlled device allowing more or less flow to happen under various driving conditions. At idle, the purge soleniod should be closed. It is a normally closed solenoid, so try unplugging it like the other poster has suggested.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">As an emmisions requirement, fuel tank vapors need to be trapped and later purged into the manifold to be burned. The EVAP Purge solenoid is what does this job. It is a pulse-width controlled device allowing more or less flow to happen under various driving conditions. At idle, the purge soleniod should be closed. It is a normally closed solenoid, so try unplugging it like the other poster has suggested.</TD></TR></TABLE>

Yes I actually just read about this some more last night. I found out also that if you unplug the purge solenoid, it releases them through a valve on the actual canister into the atmosphere instead of into your intake, as a saftey precaution.