re: post skunk2 intake manifold install idle probs / 94 gsr

not fixed
repaired evap control canister with jb weld (thanks to GS-Racer01 for the suggestion - epoxy broke off just like i used a children's glue stick). ran brand new vacuum lines, completely bypassing the iab (which was not how it was installed). disconnected iab solenoid 2p. complete de-ricing of engine bay. problem still remains. the only other place that i know of for a vacuum leak is btwn the tb and the im or btwn the im and the head.

more details
i have a perfect, unaffected cold idle warmup with no fluctuation. when i reach a certain temperature (after say 1-2 minutes), the fluctation begins. it's a very rythmic rise and fall; uuuuuup, down, uuuuuup, down ranging almost exactly 1500 rpm. after the car has warmed up, the range falls for example 3000-1500 then after warmup 2500-1000. (fyi, the idle speed was set to 1000 by the installer to help with tb problem). complicating things is the existing tb plate stickage, which i know from years of experience living with it; jerky low rpm (under 3000) operation. i'm thinking iac is causing the systematic idle fluctuation, but don't really know.

anyone have any ideas???

-g

 

fyi

 

is this a side effect of the tb coolant bypass? my understanding is that this can cause some fluctuation/erratic behavior before the engine warms up fully (but not after).

i've verified that the coolant lines to the iac are in order and the iac 2p is plugged in.

fuel pump? i'm really grasping at straws now...

 

No. The coolant bypass never affected me.

What has changed since before this was a problem? I would say to get another canister (salvage yard) and see if that fixes it. My opinion is that if that was the only thing that has changed, that would be where the trouble lies.

Good luck.

 

that's good advice. i'm searching for some other reason because i'm assuming i fixed the canister. haven't called junkyards yet but am assuming they'll want around $100. dealer wants $200 and a&h says $150. nice parts guy at dealer says that the junkyards "are well aware of what things cost" i guess meaning i'm not gonna be able to pick one up for ten bucks. thanks.

 

I'm just taking a shot in the dark, but have you check the play on your throttle cable. I've heard of a couple of people in which an overly tight cable caused intermittend fluctuations instead of just a fast idle that you might expect.

 

thanks. will check today.
i do know that problem doesn't change with the hood open so it's not related to clearance probs with the s2im and gsr tb.

 

hey! you could be on to something. i just remembered when i tried to lower the idle speed with the set screw, it seemed to have no effect. could this explain why?

 

are u using throttle body gasket??? if so, i would take it off and use honda gasket sealant instead. i had the same prob with mine after i installed my sk2im
and when i took out the gasket and used the sealant, idled like a champ.

 

thanks stick. as far as i can tell from the outside, it looks like they used gasket + sealant (???).

just checked throttle cable:
it's hitting the throttle stop screw and the deflection is within spec (i remeber this is supposed to be 10-12mm). i give up...i'm heading for the shop - let them deal with it.

 

wee insists this is throttle body related because the early jg plates are round instead of oval. but an idle range of 1500 may indicate something else in addition.

*** he says you must keep the iab solenoid connected ***
i noticed a little struggling around 7k so i can vouch for this.

lates...

 

u can do this yourself regarding taking off TB off of s2IM and remove TB gasket
and put it back

refresh my memory about IAB solenoid?? location too and i hope i can help u more

 

Had the same problem with my Skunk2 and the coolant bypassed.

here's something to try. With the car idling pop the hood, take the intake tube off the throttle body, you should see 2 holes inside the tb towards the firewall side. the one on the top is the IAC, the one below it is the thermal valve. try using your finger to plug the lower hole, if that fixes the problem then it is the thermal control. If not then try plugging the top one, if that fixes it then your IAC is messed up.

I ended up removing my thermal control valve (since I live in FL) and having someone weld the ports for it.

 

there's an iab canister below the manifold. on the gsr a vacuum line runs from the bottom of the evap purge control solenoid to the iab. the other nipple leads to fpr(pre-s2im). there's also what looks like a little vacuum line loop. so i ran all new vacuum lines and just mimiced the b18b in my helms - bypassing the iab. but...others here have stated that you can rmv all that stuff (ie the iab canister), it's not needed. what i was told is that you must keep the iab 2p(2?) connector attached to the iab. the connector on the iab points to towards the drivers front tire, if that helps.

 

last night installed new iac valve, new fast idle thermo valve(actually they're both used), and new rc engineering prelude throttle body. car was perfect last night. this morning it was acting a little funny. more details later after i confirm this was just cold morning related. (cold morning in kali=55° )

 

found this old prelude.vtec.net article:
"You will notice strange idle behavior on cold start if the ambient outside temp is much below 80 degrees or so. I don't think it will damage the motor but the idle will cycle oddly until the motor gets fully warmed up. I found that when the temp dips really low, it may not stop idling strangely at all, as the throttle body never warms up enough to turn off the additional air intake valve that's normally opened for cold start/fast idle."
http://prelude.vtec.net/gen5/perform...ips/tbcoolant/

starting to regret i did this. maybe this will go in the same category as aem bypass valve (i.e. kinda worthless)
not too hard to switch back but a new coolant line was run straight to the iac instead of the straight connector connecting the ends of the tb lines. (how most people do it i think).

 

YAY! its sponge bob square pants! lol my little brother watches that show... it is incredibally strange, I do belive that when these people come up with those shows they are on drugs.