civicdrivr

iTrader: (9)

As some of you may know, E30 and myself have installed the new 09 3.7l TL intake manifold on our car. His install went smoothly. Mine, well, it didnt.

At first everything was fine. Then I had a high idle after about 200miles on the setup. I checked for vacuum leaks and replaced the IACV with a brand new unit from Honda.

Right now the car will idle perfectly upon initial startup. However, once I put load on the engine (any load, from tapping the gas to turning the steering wheel) the idle will begin fluctuating between 1k and 2k rpms. I also get a CEL for code P0505, which is the Idle Control System.

Oddly enough, the power steering pressure switch is part of the idle control system. I visually inspected the switch and saw no defects.

Does anyone have any input on this or know of anything else for me to check?

Thanks in advance.

Pseudomaniac

iTrader: (1)

If the mani is bolted up and seated properly and you've eliminated all vac leak possibility, it almost has to be a sensor issue.

I'd be most suspect of the MAP sensor since you've changed the dynamics of the manifodl, but I'm not certain that the logic that checks idle queries that sensor.

I do know that accessory sensors come into play with idle control - Air Conditioning / Power Steering, Vehicle Speed. Any leads stretched too far - bad connections?

Anytime I've had oddities like this, I pop all connectors open, hit em with the electronics cleaner aerosol, dry them, and then put anti-seizing compound where necessary and reconnect. It at least eliminates that as a factor, just sucks when the plastic connector teeth break on you....stupid dry-rotting plastic.

civicdrivr

iTrader: (9)

The mani has been off and on numerous times to check for seating issues. Ive replaced all gaskets and checked the vacuum lines numerous times. The manifold isnt the issue. The MAP doesnt control idle, and if that were the issue Id be getting a different CEL.

None of wires are stretched. The only wiring I touched during the install is Intake Air Temp. The wires needed to be lengthened to reach the intake pipe. They arent shorting out either. They are heatshrinked and taped.

Im getting nervous while I keep looking at the troubleshooting steps for the PS pressure switch. Basically it goes check wires at ECU, if voltage is out of spec replace switch. Check wires at switch, if out of spec repair broken wire. If no broken wires try a new ECU.

Its that last part that has me worried

Pseudomaniac

iTrader: (1)

The painful, but less painful than buying a new computer, step would be to see if it continues to do it with your old manifold back on there of course...

civicdrivr

iTrader: (9)

Did that. Same deal

I even replaced the TB with my old one. It doesnt fix the idle issue. I think that if its doing it only when load is applied its definately an electrical problem.

Pseudomaniac

iTrader: (1)

I agree with your logic - very odd. I'm sure you've checked this... Tried pulling the PCV out and blowing on it yet to see if it's holding properly? What about the little rubber boot around it leaking? - that one evaded me on my B20 Civic for a month....

Pseudomaniac

iTrader: (1)

Here's the procedure from Honda.....

DTC P0505: Malfunction in Idle Control System

Start the engine. Hold the engine at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on, then let it idle.
Check the engine speed at idle with no-load conditions: headlights, blower fan, rear defogger, radiator fan, and air conditioner are not operating. Is the engine running at 750 ±50 rpm ?
YES - Intermittent failure, system is OK at this time.
NO - If the idle speed is less than 700 rpm , go to step 3; if it's 800 rpm or higher, go to step 4.

Disconnect the 3P connector from the IAC valve. Does the engine speed increase or fluctuate?
YES - Adjust the (base) idle speed. If it's impossible, clean the ports in the throttle body.
NO - Replace the IAC valve .

Turn the ignition switch OFF.
Remove the intake air duct from the throttle body.
Start the engine and let it idle.

Put your finger on the lower port (A) in the throttle body. Does the engine speed drop?
YES - Adjust the idle speed. If it's impossible, replace the IAC valve.
NO - Check for vacuum leaks. Make sure the throttle valve is completely closed, and repair as necessary.

civicdrivr

iTrader: (9)

The PCV is brand new, however the seal around it is not. I dont have anything leaking from it though, but Ill still get a new seal. Did the rubber boot cause your idle to fluctuate like this?

I was speaking to a Honda tech and he said I have a very peculiar situation on my hands (not something I want to hear). He recommended checking all the gaskets one more time for any air leaking. He said that since the idle reacts when I turn the steering wheel, the sensor is still operational. Its still detecting a pressure change. Im going to reluctantly check for vacuum leaks once more.

Does anyone know of a way to test an IACV? I googled "Honda P0505" and everyone who had this code replaced the IACV. I installed a brand new one last week and the problem is still not resolved, but its possible that it is faulty.

Pseudomaniac

iTrader: (1)

[QUOTE=civicdrivr;11099590]The PCV is brand new, however the seal around it is not. I dont have anything leaking from it though, but Ill still get a new seal. Did the rubber boot cause your idle to fluctuate like this?
QUOTE]

A split in that seal was the culprit for a surgey idle - but I was Hondata on that motor - and it doesnt care so much about the IACV range other than using it to regulate fuel for the idle.

civicdrivr

iTrader: (9)

Ok. Its a $2 seal so Ill replace it anyway. It was an oversight when I ordered the PCV and didnt catch it till I installed it.

The more I think about it the more I keep looking at the IACV and saying that has to be the culprit. But at the same time the idle raised when I unplug it, so....

I dont fucking know anymore.

civicdrivr

iTrader: (9)

I exchanged the IACV with another brand new one and the CEL went away, but I still have the idle issues.

civicdrivr

iTrader: (9)

Theres something wrong with either the valve (doubt it) or the ECU. I checked the wiring and everything checks out fine. The IACV refuses to close. It stays open very slightly and causes my idle issues. Ill update this when/if I get it fixed.

fuzzy02CLS

iTrader: (2)

Have you killed the battery & the backup fuse? Completely resetting the ECU? Then do the idle relearn.

civicdrivr

iTrader: (9)

Ive reset the ecu and did the idle relearn more then 10 times. No matter what the IACV stays cracked open slightly.

I checked the wiring and everything tests fine. The last thing to test is the ECU. I need to find a 6MT ECU locally that I can use to test.

Rajca

iTrader: (8)

im having someone of the same problem
was urs like this? and what did u do to fix the problem, need update

friesm2000

iTrader: (4)

see your thread

Rajca

iTrader: (8)

replied. also did the relearn and didnt help at all

civicdrivr

iTrader: (9)

This crack was the cause of my headaches:



Spray carb cleaner around the intake manifold and lower runners.

Rajca

iTrader: (8)

will do that tomorrow

AcuraGman

iTrader: (1)

Did you ever find what was causing your idle problem? I'm having the same issue.

Rajca

iTrader: (8)

runner was cracked from over tightening the corner bolt. its in my build thread.