I've had a hunting idle problem since I turbo'd my car that was due to the p28/hondata not controlling the evap purge control solenoid correctly.....
so, I've unplugged the purge control solenoid and all is well with the idle.

My understanding is that the p28 doesn't know what to do with the purge solenoid so it leaves it open during cold startup, causing fuel vapors to be allowed into the intake manifold and causing the strange idle.

Question is, if the purge solenoid is left unplugged (valve shuts off flow from the cannister to the IM), will pressure build up inside the fuel system (and subsequently the evap cannister) and cause problems?

I've been told that all you have to do is unplug the electrical connector to the purge solenoid, and plug the vacuum line from the cannister to the solenoid, which doesn't really make sense to me, because once the solenoid connector is unplugged, it is essentially like the vacuum hose is plugged anyway because the flow is shut off?

and if the hose is removed from the charcoal cannister will it not bleed excess fuel vapors directly into the engine bay?

Any experience with this would be helpful, thanks.

specs are:
2000 civic hatch
1999 b16a2
garrett turbo
p28
hondata

 

my god...its a real tech question! (kinda...)

I rode around w/ a p28 and unlpugged evap w/o any issues.

 

thanks, any other opinions welcome and appreciated.
a link to a write up about this would be great, if possible. I searched and found questions about it but no real answers

thanks again

 

crazyness, i was thinking the same thing "its a real tech question!", excuse my n00bness but u sure its not just ur iacv or fftv? mine were hella dirty and it fixed my hunting idle for good

 

I have a similar problem, that does the same thing you described, but it also while driving holding the gas steady will act like I just took my foot off the gas, when in fact i never moved it and then it just goes back to normal, like it hic ups or something.... Any ideas?

 

yea, I'm sure it's the purge solenoid, because it's fixed now, but I'm still unsure about the fuel system pressure.

 

bump this thread for more input, cause I'm in the same boat.

 

Bump ME TOO obd1 jdmd15b vtec with po8

 

bump too, i have a p28 b18c1 and sometimes my i dle surges from 1000 to 1400 and then back down and back up when im at a stop or dont have my feet on the gas... not sure what it is, i checked for vaccum leaks already too

 

i think you need to t it off and let it it bleed partial and yes it with vent into the engine bay but you could t it to bleed else where with given length of hosing or bleed into a home made canister ... be inventive--

 

bump because I might be having this problem also.


Modified by VTcivicHB at 1:29 PM 11/1/2005

 

How about disconnecting the EVAP purge solenoid and reroute both the vacuum tubes to where they connect to one another instead of running in series with the solenoid?

 

so what happens if you drive the car with the purge solenoid unplugged?