imashy14u

I recently put a turbo in my EK SOHC non-Vtec Civic. I'm having idling problems. When hot, the engine idles at about 1500 rpm. I've tried adjusting the throttle position, checked all the vacuum hoses, and everything looks good. I've ugraded the fuel system (larger injectors from a VTec Integra and hi flow fuel pump).

How can I fix the problem and lower the idle speed?

BTW: I'm still using the factory ECU, together with a TSI unit, which works as a piggy back unit (Controlling fuel and ignition timing). Even before the TSI, I was having idling problems.

Can anyone help??

Thanks.

ZexRex

most idle problems are vaccume leaks, is your idle steady at 1500?

imashy14u

Yes. it is steady. But I've checked all the vacuum hoses and everything is fine.

I've tried diconnecting a vacuum hose to see if there are any differences, and there were. The car idles even higher - 1800 to 2000 rpm and then drops back down to 1000rpm and then back up and then back down continuously, like it's searching for the correct idle speed.

Any other reasons why this is happening

ZexRex

still sounds like a leak, mine did that when the intake manifold gasket was fucked b/c the intake manifold flange was warped but im sure urs is fine.

imashy14u

This only happened straight after I put the turbo in. Never happened when it was NA.

It's really giving me the *****! Everyone I talk to can't understand why it's happening.

Can it be my fuel system. But I really doubt it.

BlinD

I'm having this same problem idling at 1.5k and its a vac leak. Cant find it for ---- though . Do yourself a big favor and get a vac/boost gauge if you dont already have one. You should be running around 20 vac at idle.

88crxSi

ok... i've been havng problems w/ my idle as well and i finally fixed it.

different problem then yours, mine was too low..

anyways.. i have become quite familiar w/ idle systems on hondas now so lets have some more detailed info..

like.. when cold is idle at 2k, and slow dropping to 1500rpm while warming up. is it ever below 1500?

imashy14u

BlinD, I've checked all vac hoses and everything looks OK. I've got a gauge and the reading at idle is about 21-22 vac.

crx88Si, cold idle is at about 900-1000 rpm and when engine warms up, it increases to 1500 rpm. Very weird. You'll expect it to drop, correct?

BlinD

Thats weird.

ZexRex

might be something with the iacv (idle air control valve), you can take it off and clean it with carb cleaner. its on the back of the intake manifold and has 2 bolts and 2 coolant hoses going to it.

so it had the same exact problem before you modded your fuel system?