PCS on B16 with P72 rom

[2kCivicSi]

I didn't notice I still had my PCS unplugged. It was necessary when using Crome bins as my engine is OBDII and supposedly the signal is different. Has anyone tested if the PCS invert option in ecTune works with OBDII engines? When I plugged it in, I get random stalling at idle and engine won't start when warm unless I press throttle >30% when cranking. This is basically same problem I had with Crome. OBDII B16 with stock PCS control and OBD1 P61 with P72 bin

[calvin]

invert worked i tested it. test with a led. PCS is normally only on when the engine is cold(led on) so if u invert it will be the other way arround. closed on start open on warm

[JaredKaragen]

Invert worked for me; I would click between inverted and normal, and it worked good.

[kelly]

OBD II evaporative system is way different than OBD I and will not work properly whether it is inverted or not. Inverting just changes from there being a problem when cold to when hot. I did get my OBD II evap system to work with my OBD I computer. I did this because I can still plug in the OBD II ECU with no changes and pass smog, and I like having the evap system working. This required an OBD I TB that has a ported and restricted vacuum source for the purge rather than the OBD II unrestricted connection to the intake with the ECU pulsing the solenoid to control the flow rate. I moved the purge connection from the intake manifold to the TB (the nipple sizes are different, but I found a SAE hose that fit on both) and then reprogrammed the purge output in software. You could just run a restriction in the line and use the factory hookup, but I did not test this since I already had the OBD I TB on the engine from when I swapped mine for a bored one. Here is further explanation about what problems will be seen inverted and non inverted: http://www.team-integra.net/forum/displ ... t=dateDESC I read over this and saw that I did not explain what happens if you invert the output with an OBD II purge system. If you invert the output, there will be no purge until 164F ECT. But when it does open up, it will be a major amount of air, and the idle will go up. The ECU will learn this and idle back down. When starting hot, the purge will be open and this results in a large air leak and possibly hard starting. And a backfire will go right into the canister probably blowing it up. And then later when the car is started cold, it will be using the learned lower idle value and the idle will be low. You may not notice this issue. If it is not inverted, you will have full purge flow until 164F. This will probably result in hard cold starting. It will also probably result in the idle cycling at some point because the car will warm up enough to not be fast idling, but the purge will still be open up and the leak will be big enough to bump the idle speed up into the fuel cut range. Then when the purge eventually shuts off, the car will just about die because the ECU has closed the IACV way down to compensate for the vacuum leak that it is not expecting at idle.

[2kCivicSi]

If this is true... then a possible fix would be to make it so we can utilize the EBC function for this purpose.. (IE output on PCS pin) When car is at certain RPM range /manifold vacuum, pulse PCS output. outside that range, hold the output at a set level to prevent it from causing a vacuum leak. At idle even, it could be pulsed at a specific DC to keep the canister purged.

[kelly]

Sounds interesting. EBC was not around when I did all of this. I still had not thought of using it because my current setup works fine. I also use certain outputs so that if I need to flip the switch and go back to stock OBD I or plug in the OBD II computer, I have no problems; purge works on all three setups. Everything works on all three setups with no changes. Yes, I am proud of this. Well, I do have to plug in a resistor for the O2 heater. I saw no need to have it there all the time, especially since the power feed for it will take out the alterantor and the alternator light (why did Honda do it this way?) if it shorts.

[Gaskleppie]

What about just disabling the purge valve? Why must the fuel gases been burned?

[kelly]

If you disable it, you should at least disconnect the canister so it does not get fuel soaked. I disconnected mine and ran the vent line from the tank to the canister down under the car, but at times I would still get a major gas smell from the vapors. I could have capped the vent line and let the pressure escape through the factory pressure valve in the gas cap. This would move the venting to the cap. I figure it is better to use the vacuum/pressure valve in the tank rather than drilling it because drilled it would encourge more evaporation whereas the factory would either require a little pressure to vent or a little vacuum to intake. The factory cap runs higher vent and vacuum pressures than the vent to the canister, and while this probably does not make much difference, I preferred to keep the evaporative system intact. Venting at the cap could still end up in a fuel smell and would be constantly venting vapor to the gas tank filler area which might eventually take a toll on the paint. And after I could tell how much vapor was being vented into the atmosphere with the vent line routed under the car, I preferred to make the system work rather than venting to the atmosphere. The evaporative systems keep quite a bit of hydrocarbons out of the air. And I may need the system intact to pass a smog check. I would rather have everything hooked up and working. I would not keep the canister on the car if it was not doing anything, but then things can always get lost or broken if they are not on the car. So I just thought the best thing to do was to keep it working and in a way that it would work with all of my computer configurations.

[JaredKaragen]

Now that explains the random gas smell I get from my car... good info. I honestly don't see a need to be able to invert the PCS solenoid; but rather if the ECU inverted the output ( - )( + ) then it would be usefull in the OBDII swapped motors.. correct?

[kelly]

Short of pulsing the solenoid, which at the time I could not do, I tried all kinds of RPM, TPS, MAP, VSS, etc. settings trying to get the stock OBDII system to work. I could never get it quite right because the OBD II system flows a ton of air compared to the OBD I system. You can get it so that it is not noticeable without a restriction (this is quite hard because you really have to restrict when it opens using more than one variable due to the major flow), but then the solenoid is switching on and off a lot. And it flows so much when wide open, I was worried about pulling so much air in that the canister would get clogged with dirt much faster. I also wanted the system to work if for some reason I lost software control (NepTune RTP). Point being, I do not remember why I did everything the way I did, just that I considered quite a few things. I spent months getting this right, much of this was due to wanting the OBD II system to work with three computer setups without any other changes. So the main thing with the OBD II system working without pulsing the solenoid is to restrict the flow. This will work fine with just a little software control (invert and keep solenoid closed until 164F). This is close to OBD I except it will purge at closed throttle. Even with the ported TB hookup, I did notice my A/F ratios got too low. Open loop, car did not stall or anything, I was just worried about prolonged stop and go in high ambient temps loading the plugs up. I do not think it even got this rich, perhaps into the low 13's when it was a very hot day and the car was idling for a long period of time while I was tweaking on the software. So to counter this, I eventually allowed no purge until over 8 MPH when I figured there would be enough flow to allow for purge of a very saturated canister. I tried RPM but this switched the solenoid more often because it would switch everytime the engine came to idle. It probably does not matter that much, I just wanted to get it so that the solenoid was switched as little as possible. I guess you really would not even need any software control. OBD I if it fails, will fail with purge on at all coolant temps. I just will not flow anything at closed throttle because the vacuum source is ported. You could just restrict the line and get rid of the solenoid. I ran with the purge on all the time (restricted - hooked to the TB) and it does not flow enough to cause any problems. I also run open loop and the purge can have a dramatic effect on A/F which I had to account for. Always runs richer, unless unrestricted OBD II setup. It is not enough to hurt anything, but I wanted it setup so that I did not have to take into account if the purge was throwing off the ratios when tuning. Inverting the output from -+ would not make any difference. If you inverted from controlling the ground to controlling the power, you would have to rewire, but other than that nothing would change. The OBD I system does not use the solenoid to directly control the flow like the OBD II does. The OBD I solenoid turns the vacuum on and off to a vacuum valve in the canister that then opens up the line to the ported/restricted TB connection. I am tired and am not going to go back over this like I usually do. I think I got everything right.