Hi all, i have a EG6 with B16 on it. Running Ek9 intake manifold. Had hunting RPM (bouncing off 1000 -2000rpm) everytime i come to a stop at traffic after cruising for while. Occasionally i also have rpm hang at about 2000 rpm. Both of which i cam easily get rid off by turning off the A/C.

i did my fair share of research and decided to switch out the IACV, noting that mine was old and might had been dirty and causing the issues. However, after switch out the Genuine IACV meant specifically for my IM. The problem still persist.

Any help will be greatly appreciated.

 

Switch it out with brand new OEM? Or another used unit?

 

Hi... i switched it with a brand new unit from OEM.
Update: i checked my coolant level.. its topped off with no sign of leak or bubbles. Had my heater core bypassed.

 

And what engine management do you have?

 

im running Link G4

 

If IACV isn't the culprit and you don't have a vacuum link, I would suspect engine management (aka the tune).

 

but the thing is ... it was driving fine the last 1 year. the problem came recently. cant coolant temp sensor or switch cause idle prob?

 

The switch, no. It only controls the rad fan. The ECT can cause weird behavior but I honestly don't remember off the top of my head if idle is one of them. I do believe your fuel economy goes to the crapper being the ECU thinks the engine is never warmed up and stays in open loop mode. The car also runs rich constantly.

 

did a check on the ECT sensor and TPS sensor... the TPS sensor harness from PCM doesnt produce 5.0v steady... it was showing 4.88 and slowly reducing in number. am i correct to assume the readinng from the harness IS indeed supposed to be 5.0v only?

the ECT harness wire seems to be corroded. was unable to get a good voltage reading from the harness

 

Do you have a FITV on the bottom of the throttle body ?

 

Hi, i do not have FITV. May i ask whats the implication if i do not get 5v on the TW Sensor (ECT)? i used my logger to check... and it shows the correct ECT Temp as i compare it to my Defi guages. but i cant understand y i dun get a 5v when i test with multimeter

 

The ECT test is an OHM check at various temperatures. Not a voltage check.

TPS is not supposed to be 5 volts out, it's 4.75 or something if I recall. Your 4.88 is good for wide open. Then .475 volts for closed I think. Been awhile.

 

I meant i used multimeter to measure the voltage at the connector (from the ecu harness) for the TW sensor. should it read 5v like all other sensor connectors?

 

Pull out your idle adjustment screw and check if the o-ring is cracked or damaged. The one on my Civic was bad and was causing air to leak past it, it was also so worn that it was allowing the screw to come loose! My symptom was idle surging after car was warmed up. Easy thing to check so why not.

 

It is NOT a 5v circuit, it is a resistance circuit as TomCat39 stated above. Only the TPS and MAP sensors are 5v circuits on your engine.