SOLVED -high idle rpm, idle surging after PRC intake install

LK7R · Post by **LK7R** » Mon Jan 26, 2009 3:52 pm

Hi,

I wonder if anyone can give me some advice please:

Euro Civic TypeR
PRA ECU with KPRO
Innovative LC-1 WB on ELD15 pin
PRC intake manifold (ITR DC5)
ITR DC5 cams
Spoon 4-2-1 header + B-Pipe
Denso IRIDIUM iK22G spark plugs
ITG Maxogen air intake

Attached cal is the one i was using and it was fine with the original PRB intake manifold. No idle problems at all. I put the car to the garage to have the PRB changed to PRC intake and after the install the car has lumpy idle (please see the datalog). Normal driving is fine just the idle is high ~1500rpm and won't drop to the 750rpm that is in the cal.

Only change that was made was the PRC intake install (i gues that oil and brake fluid change has nothing to do with it ;)).

I have double checked all the vacuum lines and throtle cable.
Noticed that the TPS is 1% all the time so i played with the cable a bit and it was 0% but after some time jumped back to 1%.

Another thing I have noticed is that when i switch off the engine is sort of still want's to run for a few tenths of second. I do not know how exactly to describe it, but before i turned the ignition key to the switch off position, the engine stoped working immediately. Now i switch the engine of and it still goes for few turns. Hope you understand what I'm trying to describe.

Thank you for any advice.

cheers

Dan

fonz600 · Post by **fonz600** » Mon Jan 26, 2009 4:05 pm

Have u done the usual clean IACV solution to idle probs?

fonz600 · Post by **fonz600** » Mon Jan 26, 2009 4:10 pm

Can u stick this in your car and try and bear with it for a day and let me know what it's like by the next day.

Your Idle Valve Duty Cycle was maxed out to the left. I've put it back to the middle for just now.

Note I haven't looked at your datal;ogs, only your map but changing the inlet manifold will prob mean your A/F will need tweaked.

LK7R · Post by **LK7R** » Mon Jan 26, 2009 4:16 pm

Thanks for reply Fonz (i know you would be lurking here ;) ...) the Idle Valve Duty Cycle was maxed becouse I was trying to test most of things before posting problem. It did not help if it was all the way to the left or to the right or in the middle. Just frequency changed (obviously).

The thing that is realy odd is the high idle :?: it doesn't matter if the car is cold or hot - no change at all. It's still around 1500rpm and won't go down. And after some time it starts surging.

Will go through the sticky "IACV solution to idle probs" tomorow to make sure that nothing is overlooked but it's kind of strange that the throtle body would sudently start doing this after just straight forward removal and reinstall...

LK7R · Post by **LK7R** » Mon Jan 26, 2009 4:25 pm

Here is datalog where only 0deg map is used.

It's runing ok at the start, but then i tryied to unsettle it by pressing gas pedal a bit and then it started again from frame 1800 up to frame 1900.

fonz600 · Post by **fonz600** » Mon Jan 26, 2009 4:39 pm

Were new gasket used?

Also Your MAP at idle is a little bit lower than most cars I've tuned so u could be drawing air somewhere. Try spraying soapy water over the joins and hoses etc to see if it bubbles.

LK7R · Post by **LK7R** » Mon Jan 26, 2009 5:06 pm

New gasket between throtle body and intake manifold was used. I have Hondata gasket between intake manifold and engine block, that was reused. I'm also suspecting some vacuum issue. Will have closer look tomorow.

Also looked in some other datalogs from before (taken from my garage where the problem datalog was taken - so no altitude variation is in play) to check the MAP and it is similar to the datalog i have posted ~290 mbar at idle.

LK7R · Post by **LK7R** » Mon Jan 26, 2009 5:10 pm

Also please notice, that the Fuel Status is constantly changing to Open- Driving | Closed.

Confused ... big time!

cranny · Post by **cranny** » Tue Jan 27, 2009 12:28 am

iacv stuck open sounds like. take it off , take it apart , clean it till it spins freely.

LK7R · Post by **LK7R** » Tue Jan 27, 2009 10:06 am

Ok,

i vent trough the IACV cleaning - it was dirty , but moving without any trouble. I cleaned it anyway (those screws!!! ... agrrrhhh... what a pain!).

The problem is still there. So it wasn't IACV.

Any other suggestion?

cheers

Dan

LK7R · Post by **LK7R** » Tue Jan 27, 2009 1:24 pm

:( Hondata - please?

cranny · Post by **cranny** » Tue Jan 27, 2009 2:30 pm

you have a vacuum leak than

Post by **Spunkster** » Tue Jan 27, 2009 3:06 pm

From all indications you have a vacuum leak. You'll have to completely go over the installation of anything you touched when installing the intake manifold and throttle body.

LK7R · Post by **LK7R** » Tue Jan 27, 2009 3:49 pm

OK, vacuum leak is better than anything else ;) ... will check it out.

thank you

fonz600 · Post by **fonz600** » Wed Jan 28, 2009 8:58 am

Since you have re used the inlet manifold gasket I'd be leaning towards that but like I said ealier in the thread try spray soapy water around anything that should be sealed and on hoses etc whike the car is running.