okay so im having this problem

91 hatch with b16

i change the throttle body cuz i was having an issue where my car stalled out at lights and what not, so i put this new throttle body on, it works minty for about a day or two

at this time my valves were loud so i decided to go get the lash done, well my guy that does it just does it if i drive hte car there rather then doing it if the car is off for 8 hours, so i go there he does the valves, everything seems to run great on the way home, park the car, about 4 hours later i start the car it starts doing this crazy weird idle rev kinda goes from 100-1900 constantly , like a tps sensor gone but its not,,, it only does this when the car is cold/medium temp, if i drive the car for about 2 or 3 hours the idle problem goes away and it idles normal again, does ANYONE have this issue before or know what the hell is going on, i need to fix this asap as i will not turbo my engine without it runnign 100%

thanks guys

 

Any codes?

Check your coolant level...

Um... Possibly your IACV but I dunno if you have codes...

 

hmmmm......

maybe leak in head gasket or head itself causing air in the coolant system?

when its all warmed up, metal expands, solving problem until cold again?

just my .02

 

sorry about that guys, no codes at all, you think it could be head gasket? really,,,, hmmm , now that i remember tho, there is a crack in my valve cover, not the head itself but maybe that could be causing it? i dunno just tryin to figure this out is like really crazy

 

k bled the coolant system, thought it worked but its back, and its doing it when its warm now too, so not just when it is cold, anyone had this happen to them, i really want to figure this out

 

Take off your IACV and clean it out with some brake cleaner or carb cleaner. It will more then likely fix it. It just probably has so much carbon built up that it can't get a proper reading, or it's 100% dead and needs replacing.

 

k im gunna go try that right now

i'll post results

 

Did it do that before he adjusted the valves??
When my valves were not adjusted properly it did similar stuff. Might want to check the simple stuff first

 

if its your head gasket, check it when cold and not running. Pull your plugs and look into the combustion chamber w/ a flashlight. Any coolant will puddle/condensate there and should be easily visible. Also, if it is your head gasket it will be a little hard starting. I think its more likely IVAC.

 

ok guys i just cleaned out the iacv, and its still doing the same thing, i changed my fuel filter with a brand new one as well, i didn't think it had anything to do with it, but wasn't sure nad had a brand new in the box lying around so i just did it anyways....

and yellowrexsi: its weird, cuz i changed the throttle body a day before i did the valves and it seemed to run minty, but from what your asking no it did not do it before i did the valves, so should i get the valves done again?

thanks guys for the information, any more ideas?

 

Yep. Have them done again. Mine was fine when it was cold, but when it heated up it wouldn't idle. It doesn't hurt to check them before you spend more money in something you don't need.
Good luck

 

You don't need to set the valves again unless you messed around with the rockers/cams etc. I would mess around with the idle screw...since you just installed the TB. A vacuum leak will create an rough/fluctuating idle also. Did you check your vacuum line connections?

To check the EACV, key on/ engine off. Disconnect EACV, if it clicks the solenoid inside is working fine. Next with engine running, check to see if the bypass hole's vacuum (the little hole in the throttle body right before the throttle blade, on the inside dia of throttle bore) is being affected by unplugging the eacv, it should. I would then say the eacv is not the problem.

History question. Has this problem been getting steadily worse over the years, that is why you decided to fix it? Or, did these issues arise after you touched the under hood area?

Here to help.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mntuner2 &raquo;</TD></TR><TR><TD CLASS="quote">You don't need to set the valves again unless you messed around with the rockers/cams etc. I would mess around with the idle screw...since you just installed the TB. A vacuum leak will create an rough/fluctuating idle also. Did you check your vacuum line connections?

To check the EACV, key on/ engine off. Disconnect EACV, if it clicks the solenoid inside is working fine. Next with engine running, check to see if the bypass hole's vacuum (the little hole in the throttle body right before the throttle blade, on the inside dia of throttle bore) is being affected by unplugging the eacv, it should. I would then say the eacv is not the problem.

History question. Has this problem been getting steadily worse over the years, that is why you decided to fix it? Or, did these issues arise after you touched the under hood area?

Here to help.</TD></TR></TABLE>

eacv is iacv??? or what is the eacv? anyways yea its been getting progressively worse but it used to just stall out completely and the car died before, and when i turend the idle screw down it would not idle , now it idles sometimes fine but most of the time it does the whole fluctuating idle from 100 rpm to 1900 rpms back and forth up and down, and then sometimes its weird, when i turn my lights off it goes back to a steady idle... i have no idea what the hell is wrong ,, i was thinking maybe it had something to do with the alternator but i highly doubt it, i was thinking vaccuum too but doesn't it need to be throwing a code for the vaccuum to be the culprit?

i also unplugged the tps sensor while car is running and it does nothing, should it die? or should iut just keep running? i just really want to get this fixed asap, as i want to turbo my engine but i will not put the turbo parts on until i get this engine running mint again

thanks for all your help guys, more stuff!!!

 

Underneath the Tb there should be a unit that has 2 or 3 coolant lines running out of it. The iavc. Pull that off. Open the top of it. There should be two 8mm or 10mm bolts in the top. Slide it open. Peer down inside and see the white cap? Spin it untill it doesn't go down anymore. Close the top. Put it back on. Clear ecu. Bam should work. My b16a flucated from 500rpm to 2500rpm. WRRR....idle...WRRrrrr......All day...did what i just wrote down and bam instantly worked. Then all i had to do was set the idle srew to about 750, and the inside of the car sounds great, no rattling, no flucuating, and most importantly, i sound like a stock hf at the stoplight.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Burlyirishdude &raquo;</TD></TR><TR><TD CLASS="quote">Underneath the Tb there should be a unit that has 2 or 3 coolant lines running out of it. The iavc. Pull that off. Open the top of it. There should be two 8mm or 10mm bolts in the top. Slide it open. Peer down inside and see the white cap? Spin it untill it doesn't go down anymore. Close the top. Put it back on. Clear ecu. Bam should work. My b16a flucated from 500rpm to 2500rpm. WRRR....idle...WRRrrrr......All day...did what i just wrote down and bam instantly worked. Then all i had to do was set the idle srew to about 750, and the inside of the car sounds great, no rattling, no flucuating, and most importantly, i sound like a stock hf at the stoplight. </TD></TR></TABLE>

isn't that the FITV? i already did that maybe a few months ago, i dont think it would pop back out again, but i can certainly look

i'll try it

 

okay well i just tried with eacv thing, whewre i had the key on, engine off, and when i unplugged the eacv it did not make any clicking sounds? so is that my problem all together?

 

Yes, the thing underneath the throttle body is the FITV, per many articles on H-T and elsewhere. The IACV (aka EACV) is the thing on the backside of the intake manifold.

I had a similar problem to what you describe, but not 100%. My idle would go from 750-~1900 all the freakin time. After cleaning the IACV it still had a messed idle, but it sounded different. After replacing the IACV with a known good unit, it worked fine. Cleaning a messed IACV may not always fix the problem.

A quick test I did was to start the car, and while it's idling weird, unplug the harness from the IACV. When I did that, the idle still fluctuated, but its frequency went way up. Maybe not a definitive test, but it told me something about my specific problem.

I still have an idle problem currently, but it is only until the car reaches normal operating tempreture. A clean of the FITV ought to fix that, I just haven't done it yet.

 

okay well here is an interesting one for you guys, i went out last night with the car and was just trying different stuff to see if i can try to get the idle to stay normal, well it turns out if i dont have my heat on and i turn off my lights the idle will stay normal, however if i have my heat on and try turning my lights off it does theh same thing, but if i turn my heat and my lights off it goes back to a normal idle im beginning to think its my alternator this whole time, but why would it make it fluctuate like that and it doesn't explain why it would do it during the day too then when my lights aren't even on, either way my buddy is gonna rebuild my alternator and we're gonna see if that works... i hope this thing is fixed soon i really want to turbo

 

anymore ideas guys?

 

bummmp, anyone!!!

 

Hmmm, thats odd. Did you check your grounds?? There is a ground near the thermostat housing, take that apart and sand down the connections. Did you try cleaning your battery cables? That is also weird that the eacv does not click when you disconnect the harness to it. Hmm. Did you go through the diagnotic procedures for these symptoms? I can post some procedures if you want. I need more specifics though

Model and year the electronics/engine/etc are from.
ECM you are currently using.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mntuner2 &raquo;</TD></TR><TR><TD CLASS="quote">Hmmm, thats odd. Did you check your grounds?? There is a ground near the thermostat housing, take that apart and sand down the connections. Did you try cleaning your battery cables? That is also weird that the eacv does not click when you disconnect the harness to it. Hmm. Did you go through the diagnotic procedures for these symptoms? I can post some procedures if you want. I need more specifics though

Model and year the electronics/engine/etc are from.
ECM you are currently using.</TD></TR></TABLE>

its a 91 b16a sir in a 91 si hatch
ecm is what?

im using a pr3 spoon chipped ecu

i haven't done any diagnostics and if it were a ground why would it do it all the sudden tho? i just dont think that makes sense, i can sure check but that seems weird

 

k guys still having the same problem really want to get this figured out, im gonna try to clean up all my grounds today and also im going to put on a new iacv and see if that does anything... i took my intake off and while the car is running i put my finger inside the throttle body on the little hole and the car died, is it supposed to die when you do that and if it does then what does that mean (it was the most upper hole)

and i know its not coolant for sure cuz i just replaced my rad yesterday wiht a half rad from an eg so i dumped it completely and put new stuff in, so no coolant air pockets

please help getting this thing running minty again!

 

here is a few things to check.

Mine did the same thing.

First check to make sure no air is in the coolant system. Fire engine up and use the bleed screw (it is there on a d16) on the front engine where the top hose goes into.

Also you took off the throttle body, did you clean off the old gasket and replace with a new gasket. If the gasket was damaged it will let air in and make your car idle like hell.

Mine ended up being a piece of gasket 1mm by 1mm in between the intake manifold and the head. Pull everything apart found that and said there is no way it can be that but removed it. Replaced all back again idle issues gone.

 

Redo the valve adjustment. If they are too tight the car will run bad. My car would not even idle when I did mine wrong and tightened them too much. Another trick to check if it is the Fitv is pull the intake off, on the inside the opening for the throttle body you will see a hole on the firewall side of it. Plug the hole with your finger. If the idle goes to normal, you need to tighten the fit back down. Most like it is the valve adjustment if it was not doing it before the adjustment, but started after. General rule of thumb, if something acts up after you did something, than that is usually the reason why.