GS-R Civic

I've searched a bunch and never found a solid answer.

Last weekend I swapped in an OEM intake manifold ported to 70mm to match the skunk2 alpha series throttle body. I used an OEM intake manifold gasket and plastic p2r throttle body gasket. Bled the system well with the coolant bucket thing, then billman's bleed method and then 2 days of daily driving and opening the bleeder at the end of the day.

So right after the install, the idle was at 3000 and would drop to about 2500 when warm.

I swapped my iacv from my original manifold and it got better, cold start idle at 2000, about 1500-1700 when warm, dropping to 1100-1200 on occasion. While driving and I let off the throttle the rpms will drop to 2000 and hang for about 5-10 seconds then drop to 1500.

Tonight we put a vacuum gauge on her, 22-23 in/hg on cold start and when warm. We also sprayed tb cleaner on the tb gasket, on the egr block off plate(just did the air pump remove as well), around the MAP sensor and IAT all with no change in the idle speed. The idle screw on the throttle body is backed all the way off and its not sticking open. We tested the voltage of the TPS and its dead on.

I removed the fuse to reset the ecu twice.

I am about the swap the original throttle body back on to see if it makes a difference. I also picked up a new OEM throttle body gasket, but don't think it will help because of the normal vacuum reading.

I am getting tuned in a week on aem v2, so if it is an air flow issue due to the new mods that the stock ecu can't compensate for im guessing well work it out with the tune? I just don't want to bring it to the tuning session with a problem that I should be able to fix on my own.

Any ideas would be greatly appreciated!

(other mods include k&n fipk intake, plm header, 70 mm tp, 70 mm single exhaust izze air pump delete) everything was normal with these mods.

GS-R Civic

I cleaned the IACV really well yesterday and went for a test drive. The rpms still took a while to drop down, but it didn't stop at 2000 anymore. Warm idle still around 1500.

I swapped the stock throttle body back on this morning, cold start up and idle is around 1200-1400. So I guess even though the throttle plate was open air was still getting through.

Now do I leave the OEM sized throttle body on with the 70mm bore intake manifold or do I go through the headache of putting the original manifold back on before my tuning appointment on Friday? Or do I order and try to get another throttle body overnighted to me this week...

c130turboprop

sounds like a vacuum leak. check all the line connections

dantediss

This may sound silly but how tight is your throttle cable ?? It may be a tad too tight giving just the tiniest bit of gas keeping your rpms a little high. Remember check the silliest and dumbest things first before going nuts

STOUK

I'm having the same problem...did the samething you did...also called skunk2 and all they said was I needed a bigger tb gasket which I have..no help there....I took mine off after 5 hrs of trying to get it under 2000rpm....played around with the tps voltage and the idle screw as well as the throttle cable and still nothing...I took it off and havent touch it for a few months now so the stock tb is back on...when I had it on and it idle at 2krpm...I drove it around and the responce was fantastic...I would love to get it fix and running right on my car...might try to install it again in a few days to see if I can fix the problem...ill let you know what I find if I can fix mine..

soccaz34

Any fix to this?

beefystud

sounds like you didnt calibrate your tps

soccaz34

How do you calibrate the TPS?

LaosguyAP1

go to 9:50 mark, shows you have to calibrate the tps.

s2000Junky

Been using the same 70mm SOS TB for nearly 10 years without issue. Its a modified oem unit, which I highly recommend. There are issues with throttle plates sticking and some other issues on some of these aftermarket options. I wouldn't bother with them myself. To the OP about going to the trouble of swapping the manifold back, no its not, just leave as is.