Si-Yaaa!

I just installed stage 2 cams, skunk2 intake manifold, cam gears, mugen head gasket, type-r outers and portflow inners, and a Prospeed ECU program with the fuel cut off at 9200 rpms - on my 95 GSR swap running the chipped P72 ECU. When I fired up the car for the first time, it idled high, like 2k, then 10 seconds later it started bouncing up and down from 1000rpm-1600rpms. We unplugged the IAC and the idles stopped bouncing but held high at 1500rpms, but if you press the gas a little, it would bounce again but faster and not nearly as bad. I checked for vaccum leaks, checked all the vaccum lines, checked the gaskets (new), reset the ECU, and checked all the sensors and everything is good to go. We did notice that on the Skunk2 Manifold, only one of the nuts was holding down the fuel rail because there was a big gap on the outside two studs preventing the nut from going all the way down. We did not put on the three orangish brown round plastic spacers from the stock mani and fuel rail - is that right?

Any help is greatly appreciated because I'm moving San Franicsco on sunday and need to get this worked out. Thanks again.

p1ccoloz

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Si-Yaaa! &raquo;</TD></TR><TR><TD CLASS="quote">When I fired up the car for the first time, it idled high, like 2k, then 10 seconds later it started bouncing up and down from 1000rpm-1600rpms. We unplugged the IAC and the idles stopped bouncing but held high at 1500rpms, but if you press the gas a little, it would bounce again but faster and not nearly as bad. </TD></TR></TABLE>

that sounds pretty normal, esp when you first fire up the car it's gonna idle high but when it warms up it'll lower, IMO everything is fine

Si-Yaaa!

When the car is warm, it still idles from around 900rpms to 1400rpms. That can't be normall. I can actually see then engine torque(move) everytime it goes down to the rpm where it rises back up. It's like someone is pressing the gas pedal down and reving it.

Si-Yaaa!

I just lowered the fuel pressuer, it was at 43psi with the vaccum line plugged in, so I removed the vaccum line and set it to 38psi and now it has a way better idle, it's alot more stable, but it still jumps up and down after you press the gas, but only bounces a couple times then settles back down. So do I need to fine tune my fuel pressure. And it still idles at 1200 but I can't turn that damn brass set screw on the TB for some reason.

92lsr

try a stock gsr p72 and see if that helps , i have a mugen p28 program and the idle kind of bounce around 600-1200 but mostly at 800-900 i reset the the ecu and put the stock ecu to see a diffrence the car idle perfect now , try cleaning your iavc whatever is called on back of the intake mainfold with some carb cleaner

Si-Yaaa!

Ok, so I just took the car for a drive, and the idle is bouncy again. It goes from 900rpms to 1400rpms now. It's weird, its like a steady pace, like a rythm. I wish I had my a obd1 ecu to try, but I don't because I got my P72 reprogrammed. I took it to honda and they said to spray everything down with carb cleaner, and check for leaks. I did this and found no difference, but the carb cleaner bubbled alot, but I think it was due to being hot. Only thing else I could do is get try another ecu, and hope that works. I just gotta find one. And I will clean off my IACV and hope that fixes it. Its just wierd how it's alot better with the iacv off. But the car feels really strong now with the cams and manifold.

JDM_Risa

iTrader: (1)

don't worry i just got my car tuned like 2 weeks ago it idles like that the Skunk Stage 2 cams have a loppy idle i think its kinda tight domestic get scared of me when i am at the light ppl trip over my idle i ilde at like 1100-1450 all day long and when i first start the car it starts off high like aorund 2k so i don't think u have to worry

hell yeah the car feels strong with those cams...when vtec hits it pops hard......i don't think its your ecu its the nature of the cams.......ever heard a domestic with a beefy cam it revs up and down all the time.....i guess skunk s2 are kinda beefy

one time my car this vacuum line popped off it cause my car to do that too when i had type R cams i was like wtf thought i had bent valves .........then i notice the line fell off...i was dumb anyways taking itr cams to 9k on stock valvetrain on my GSR head

WOTTEG

Swags04 is having a problem after his Skunk2 IM install as well:
https://honda-tech.com/zerothread?id=596955
Maybe you two can cross-reference the details of your installs to find cause.

As we know, extra air in the cylinders that is not "metered" by the TB/IACV/FITV/EVAP makes the idle rise, then the ECU tries to compensate and it drops, then it rises. This happens at different rates depending on the size of the leak.

I'm sure you know this, but it's called "hunting idle".

It makes sense that you have a better idle with the IACV blocked off. This just tells us the IACV is OK, tha you have a leak somewhere else.
There is excess air entering your IM from somewhere, and the with the IACV blocked off, the leak will "act" like it is doing the IACV's job (letting a little air bypass the TB).

I'd re-check ALL the lines that go into your IM again:
IACV
FITV (If applicable)
EVAP Purge solenoid
PCV Valve hose
Disconnect the hose leading to the IM from the source you want to test, and block the end of the hose so no air gets into the IM from that connection.

My (replacement) PCV developed a leak , and the leak was sufficient enough to create a hunting idle situation.

I have never removed/installed injectors, but it makes sense that they could be the source of your leak. I suppose you already tested thier mounting surface with carb cleaner? You are supposed to coat thier ring seals with oil before installing them, if this was overlooked then I could see the seal not being adequate from a "miss-seated" seal ring.

Tell us about how you removed the old IM and gasket please. . . Did it ALL come off? (SOmeone here posted that they didn't remove all the old IM gasket before mounting thier IM and couldn't figure out why they had a leak. . . ) Could the surface fo the head been marred by not using a thin brass/copper putty knife? This would cause leaks.

We'll get you through this, You might want to check with Swags04 and see if there is anything in common. . . .

Comp97GSR

You will definitely need to tighten up your fuel rail with washers if you haven't already. Are you using a different t/b?

ImportAuto99

If i were you, see if you can bypass ur fast idle thermo valve. that made my idle "more steady" now it only fluxuates from 800-900 or 900-1000...But now my car miss's alot..so i have a whole new problem... skunk 2 manifold

One Bad GeeSeeR

hey dont you have a red si with greddy turbo kit that goes to sf state? btw i am not a, i think we met like two or three years ago, when you put your car in hot import nights in san mateo.


Carlo

darkirony

really suggest getting an safc fuel control for the new ****. trust on that

92lsr

did you reuse the gsr tb gasket , spray some carb clean on the gasket area when the car idles , my friend had this problem make sure there are not craks in the tb gasket

Si-Yaaa!

WOTTEG: Thanks so much for you input. I'm going to try to fix the problem tonight. I'm going to do what you said and pull off all the vaccum lines and see if thats the problems. When we pulled off the original Intake manifold, the gasket was all over, so we had to use a gasket scraper, and it was a real pita. It was a little mared up, so we lightly sanded it to take off any burs. When we put the new gasket on, we used silicon sealent too - just in case of a leak. An the throttle body gasket is new too - I'm pretty sure we took off all the chunks of the original too, but its vauge in my mind so I'm going to check that too. And I did not put oil on the injectors seals, do you mean the seals that go into the head or the fuel rail(never removed mine from the fuel rail)?

And I borrowed a buddies ECU, so I'm going to try that tonight too. I also have a VAFC for tunning and you could clearly see the vaccum fluctuating.

And Carlo, I do have a red turbo Si, but it's going to sit for a year because I can't afford insurance on it and I don't trust that car on the streets of SF with it anyways thats why I got my 91 hatch.

Thanks for all your help and support, if I get this solved, it's all thanks to you guys. I'll be back with an update later tonight. Thanks again!
---Evan

Si-Yaaa!

Ok, I don't know why, but I started the car tonight, and it runs really good. It idles great, maybe a little low actually (650-700rpms) So I guess my problem is fixed, I don't know what we did to fix it but it works. Maybe the ECU had to re-learn something? I just hope it will stay like this. Thanks alot for your help guys!

92lsr

did you put the stock ecu in or your chipped one ? glad to hear its fixed

WOTTEG

Si-Yaaa!:
How many days of driving before the problem stopped?

Per the injectors, the oil goes on the "seal rings" that fit between the injector and the IM.

This is great news!
Please update us as you can.

Si-Yaaa!

WOTTEG: I have been using my 00 Si to drive around untill I got the problem fixed and have only been working on my 91 Si when I get home from work, and before work. So it really seemed like the longer I let the car sit, not running, the better the car got. Like it basically just took three times of starting the car from a cold start for everything to be fixed. So maybe everything just had to seal? Hmm, maybe it's better not to think about it and just drive it, hehehe. And I doubt this is it, but maybe the carb clearner made a seal of some sort on the injectors becaues we sprayed it everywhere. But man, vtec pops so hard now - beautiful.

And I used my prospeed chipped P72 ecu, I didn't even put in the stock P61 ecu that my buddy let me borrow. I'm going to drive the car today to work and back and see if it stays good to go. I really hope so too because I gotta make the trek to San Francisco on Sunday.

Again, thanks so much for all your help

iH8RICERZ

iTrader: (1)

When i did my skunk2 IM install on my 94 GSR....i kinda ran into the same problem. I had to tighten down the bolts holding the manifold on to the head, and I had one plug plugged in the wrong spot. Also, I was using an itr throttle body gasket, and that definately didnt work...had to switch back to the GSR gasket. I plugged in my custom all motor chipped p28, and now the car runs like a charm