JDMEMone

Hi guys, So last year I put together a B16 its on Pro 1's and high comp pistions and its been tuned. ran perfect all last year, so over the winter I redone a little bit of the wire harness and double checked everthing with another oem harnes and everything was pefect.
Now I am having a problem with the car idling at 2k and surging even when its fully warmed up. I have burped the cooling system, replace swapped the IACV checked for vacuum leaks if I unplug the IACV the car idles at 700 but then dies. anyone got any suggestions?

simplejackk

The name of the valve is escaping me, but the pcv valve that sits either on or under your intake manifold, Could that be going out? When i installed a 70mm throttle body and intake manifold mine was idling super high, even after being warm, and when i unplugged the iacv it idled but died shortly after and i replaced that valve and it was ok.

JDMEMone

That is blocked off, Im not running the pcv. Everything is blocked off. Bypast the FITV on the TB so it runs directly to the IACV.

JDMEMone

So I was messing around with the car today, and I switched out MAP sensors and when I unplug it while its running it barely idles. (pro 1's) but when I plug it back in it still idles and 2k and surges to 3k. so I got the bright idea and plugged pulled the connector on the MAP sensor on the TB and plug it into a MAP sensor that was out in the open and it idled perfectly. Can anyone explain this?

JDMEMone

Calling on RonJ??? So i have tried everything, I pulled off the intake mani last night and now im gonna see if it has any vacuum leaks and check every where else. ANY SUGGESTIONS ANYONE????

JDMEMone

anyone?

Former User

Any CEL codes?

Have you checked the FPR?

JDMEMone

No code, car is EM1 but tuned on Neptune P28, I have not checked the FPR but i do and a fuel pressure gauge on the Rail but i dont remember the PSI, when I put the mani back on I will update, but i will mention, that when a pinch off the return line that comes off the stock FPR the car idles normal.

em1hondaguy

Id check for a vacuum leak first. First put your intake back on. Then buy a vacuum gauge and see how many inches its pulling for vacuum. Or another easier way is to buy a can of carb cleaner and while the car is running spray around the intake if theirs a leak the idle will drop down. Now you can also just take a ciggarette or cigar and take a hose and blow smoke through one of the vacuum ports if theirs a leak smoke will come out where ever the hole is. I dont understand why you guys bypass your pcv systems on these motors. B16 are picky about that. I work for honda and every civic that i have worked on that has a b16 has had the idling issue because they try and bypass the pcv system. Its designed to relieve crankcase pressures and the air it is releasing is used to control and stabilize the idle and iac. Reconnect your pcv. Also have you tested your iacv? I will post the alldata info for you tomorrow so you can go through your car and check everything. These motors arent like the older motors where they have the thermal idle control valve and you can bypass them. The air coming into your motor is always changing and the iacv cannot adjust for that constantly by using the pcv sytem it is using a constant controlled amount of air venting from the crankcase to control idle. Also having the crankcase ventilation blocked off is gonna cause problems for you. The excess pressure now stuck in the oil pan/block now is building up can cause unstable oil pressures and rob you of hp. It can also cause you to blow out seals in the bottom end causing oil leaks.

JDMEMone

EM1hondaguy i have used the starting fluid test with no luck. I dont run the PCV because I have a catch can, the black box is plugged and the two fittings on the back are running to my catch can. tonight i will put the intake back on, do the smoke test. Also i have a IL4 TB thats a 68mm, and the coolant lines that go to the Thermo Idle are plugged and the coolant line that come of the head to go to the TB, that is now bypassed and runs to the IACV. I will also check the fuel pressure at idle. (surging idle)

em1hondaguy

Starting fluid wont work. But i dont think u have a vacuum leak. Im thinking either you have a faulty iacv a bad map or bad fpr. I will post the alldata test on how to test the iacv and map sensor with a voltmeter. Cant remember but with the p28 ecu u could
Jump certain pins to make the cel flash codes at you. Also check the number 15 fuse when that fuse blows it causes the alternator and o2 and speed sensor and various other sensors not to work. And your sure you have no air pockets in the coolant system. Also check temp sensor to make sure its reading properly if giving an inaccurate temp the ecu will then have the iacv change the idle and other sensors such as tps and map will think the engine is running hotter than it is and the ecu will change those setting as well to compensate. And cool sorry for the misumderstandin about the pcv thought u just elimanted the crankcase ventalition

em1hondaguy

If you have a thermo idle valve on you intake are you running an older b16 manifold

JDMEMone

EM1 Thanks for helping man Its a Type R intake mani, with a inline four throttle body. Check the fuel pressure today after i put everything back in and at idle (2500 rpm) lowest i could get it was 55-60 psi. then i pull the connector on the MAP sensor and hooked up on that was open the the atmosphere the idle idle at 1k and the psi was still 60 psi