stackz

ok, I'll try to make this not so long and keep it understandable haha.
BACKGROUND
STAGE 1
93 dx civic hatch. Engine is a stock b18a1/cable trans from a 91 integra. I had the engine first in my 93 dx and was running it completely stock with a p75 computer and the civic engine harness and injectors since they are already obd1 and were the same 240cc injectors as for the LS engine. I had absolutely no problems in this fashion with anything running this way.
STAGE 2
totalled the dx and bought a cx body. Put the engine/trans (as it was) from the dx into the cx and it ran just the same, perfect with no problems. Only difference between the two bodies is the cx was a stickshift body so I changed mounts and converted the cable trans to hydraulic with a clutch fork kit. again, no problems running n/a in the same fashion as I did on the dx.
STAGE 3
I bought a used b16 greddy turbo kit and an ebay intercooler kit as well as I'm running a d-series bluebox piggyback due to having the civic injectors. I got it all installed and spliced to the far right back vacuum port for the boost gauge (The one the fuel pressure regulator was going to). I didnt have the type-s knockoff bov hooked up at this point as I had run out of vacuum ports to use without splicing too much. Anyway, in the same fashion as above with the simple addition of the turbo kit/bluebox/splice for boost gauge, the car ran just the same with a little extra power
STAGE 4
got tired of hearing the turbo cavitate so I ran a line from the top side of the type-s bov over to where I tapped in for the boost gauge so now I had the boost gauge and bov sourcing from the fpr's vacuum point. Couldnt get the bov to blow off but had no idle problems at this point.
STAGE 5
I figured at this point, I wasnt getting a good signal vacuum to the bov so I re-arranged the "T" setup so it goes as follows: manifold vacuum point-->T out line and bov feed-->T out line to FPR and boost gauge feed. Now the bov blew off and I still got same readings on boost gauge so I assumed all was good.
PROBLEM #1
about a week after doing this, I started getting a weird irratic idle that would be at idle when warm or cold. The engine would run up to around 2k rpm and bounce from there between 1.5k-2k rpm. If I blipped the throttle after coming to a stop it would idle back down to 700-900rpm idle range until I took off and then came back to an idle again.

I rerouted my hoses again to bring the FPR and boost gauge back to the only splice in that line and then put the bov over on a "T" for the charcoal canister and this thing that's attached to the frontside of the intake manifold (was told it was some sort of vacuum assist for the cruise control??). Anyway, it helped the idle.
PROBLEM #2
a week after doing this, the idle problem came back and this time it was steady bouncing at around 1.7-2k rpm and if I blipped the throttle, it would idle down to stock and then just go right back up to high idle. So I rerouted again, this time putting the cruise thingy back by itself and tapping in with just the charcoal canister port. Kinda weird but at this point I noticed the other line from the charcoal canister goes over to the MAP sensor and then from the MAP sensor to an intake manifold vacuum port.
PROBLEM #3
about another week went by without incident and now it's doing it again but at 1.4-1.6k rpm almost steady and if I blip the throttle, it idles back down for a second and then goes right back up. So I then put the charcoal canister back by itself and gutted that little cruise thingy so that it receives signal from right at the throttle body and then the output goes to the bov as the feed for it. Its gutted so I'm getting vacuum from both the throttle body area and from inside the intake manifold itself. Ran great for two days and the exact idle problem is back.

I have no clue what to do?? I cant tell if I maybe fubar'd the FPR or the MAP sensor or if that little cruise thing is actually something else function wise?? I dont wanna just randomly throw things at the car either. I wanna figure out what I did wrong to cause this?? Other than the fact that it uses more gas from idling high all the time...and also that it runs hotter at idle because the engine is revving so high...it's irritating as well because the high idle causes it to buck around in 1st-3rd gears due to the high idle wanting to kick the engine into bog mode around those rpm's.

pain in the butt if you ask me.

My next course of action is to unhook the greddy bluebox, and unhook the boost gauge and the bov and drive around the subdivision some (that way I stay out of boost since I'll have NO fuel support at that point) and see if back in n/a mode, the problem is still there or not as I think that'll give me a clue that I pretty much fubar'd something that was working just fine before I did the turbo swap.

does this make sense to you guys??

stackz

haha, I thought that was kinda quick for a response :P

yeah, I didnt want to post that much info but I figured getting it all out there history-wise at the beginning would help people think the same way about the problem as I am instead of just throwing out suggestions that have no relevance to the situation like I see so often...

and no, no codes from the computer either guys. just this weirdo idle problem.

RotaryGeek

maybe a vaccuum leak from your t and the manifold, or after that.

stackz

I thought that as well, so I replaced every vacuum hose on the engine with a new one lol. I guess I can go back and check to see if any are loose or maybe I tore the end of one from moving them around so much?

stackz

hmmm, while searching google images for vacuum routing diagrams I stumbled on this little write-up

http://www.ef-honda.com/ben/Badidle.php

I think I'll give this a whirl since at minimum, it'll let me knock out two possibilities haha.

stackz

according to this pic, the fuel pressure regulator should be connected to the charcoal canister and not to a vacuum source on the manifold?? and it should have a check valve inline with it??

anyone run their stock fpr straight to a vacuum nipple on the manifold??

http://www.superhonda.com/photopost/data/502/b18vac.jpg

jxr1774

my fpr is connected directly to the mani... or maybe it is connected to a t with the boost gauge then to the mani. Either way its the same idea.

Tom-Guy

Either you can't see it isn't connected to the charcoal canister, because superhonda.com guys are idiots who think no-resolution pictures are helpful, or it is hooked to the charcoal canister because superhonda.com guys are idiots. The bottom line here is superhonda.com guys are idiots, and you need to just run that ---- to a port off the IM and throw away the OBVIOUSLY LABELLED fuel pressure regulator control solenoid on the firewall, the one running to your muffler bearings in that picture.

stackz

lol, yeah they can be idiots on that site sometimes :P

I followed this little test write-up and when I put my finger over the FITV valve, nothing really happened and then when I put my finger over the hole for the IACV, the car died almost immediately. This may be my problem. I'm gonna hit up the u-pull friday afternoon and pull a few of them off some cars and see if one of them will fix the problem.