For those that don't want to read the whole thread:
My car won't idle right.
W/ everything plugged in, it revs to 4k rpm.
If I unplug the IACV, it cycles between 1000 and 1200/1300, as if I were barely pushing on the throttle and then letting off, then repeating that.
If I unplug the vacuum line going from the TB to the MAP sensor, it stops cycling.

WTF?


Well I did a D15B swap into my HF and I thought I connected everything right but when I go to start it up, it revs and keep going up to as high as it can before I turn it off.

Can anyone help me? I have no idea what's causing this and it sucks. I don't want to damage my fresh new motor by revving the hell out of it when it has been sitting for a while. Do you think this could have damaged it already? I've started it 3 or 4 times and each time it got to about 4k before I shut it off.

Here's my setup:
91 CRX HF
91 JDM D15B
generic intake, b18a1 throttle body, d16y8 intake manifold, header
Zex ~6 lb. flywheel
91 Si tranny

I'm staying OBD0 for now so I'm running a PS9 (Auto PM6) and the only code I'm throwing is 19 (auto transmission).

At first I thought it was my throttle cable since I had to kinda ghetto rig it (bend the bracket) but it isn't...

I don't think a vaccuum leak could cause it to rev that high...

Could timing be a problem? I installed a new timing belt and wasn't sure 100% I did it right... if the timing belt was on and the crank and cam weren't lined up correctly could it be doing this?

Also I am using my stock distributor since I'm staying OBD0 and it seems to be working fine so I don't think that could be it either.

Checked to see if I switched MAP and TPS sensors, I don't think I did...

I'm really stumped and it sucks *****! So if you have any idea please let me know!

Thanks!
Scott


Modified by whizdumb at 2:32 AM 1/31/2005

 

It could be the throttle cable still, as if there is any kinkage inside the protective covering it will lock in place. Also, do you have a leak anywhere coming off the intake manifold or the throttle body? What else can I think of.....is the butterfly on the TB closin g all the way at idle? That would be the first thing to check as if it is allowing air in then you pinpointed your problem.

 

did you switch the tps wires?

 

Damn this is really starting to bother me!

dr_latino, thanks for the idea. I checked the throttle plate and it's all the way closed...

It's still getting air into the head somehow, most likely the intake mani??

I used all new gaskets but the first time I put it on and filled up with new coolant it had a slow leak on the part where coolant goes through the intake mani gasket... so I scraped all the rest of the old gasket crap off and put it on again. Should I get a new intake manifold gasket? I'm pretty sure I scraped everything off from the old one.

Could I have my vaccuum lines mixed up? I followed the diagrams in the Helms for an HF and I'm using the D16Y8 mani... shouldn't all mani's be pretty much the same? Does it matter what nipple I use as long as it's the right size and goes the right place?

I might be able to get a picture of how I have mine if someone could look at them and tell me if they are right or not.

But I'm still thinking it has to be the intake mani-->head where it's getting the air. I checked all bolts and all are tight.

 

check the intake mani gasket and throttle body gasket

 

civickiller, I don't think I switched 'em. I thought that might have been it but I don't even think my TPS sensor plug will reach where the MAP is. The way I have it now, the wiring for the TPS comes out by where the distributor wires are and MAP wires come out by the alternator and injectors..

messeduprex, yeah I think I am going to have to replace both of them and make sure both mating surfaces are extremely clean.

Thanks for your help guys I guess I know what I have to do now.... hopefully this fixes it!

 

completely disconnect your throttle cable. if it still doesnt do it you have elimniated the throttle cable theory.

Is the TB stuck open?

Did you block all necessary vacuum ports off IM & TB correctly?

vacuum leaks will create this if they are bad enough...

 

i remeber one time i forgot to reconnect my iacv and it did the same thing,scared the **** outa me.i went to start it and vvvrrrrrmmmmmmm.it is mostlikely a fatty leake somewere. something simple that you should be able to find easily,when you get a small leak it will rise but not as abruptly as say a huge ******* hole in your manifold.

 

Does your Y8 Manifold have the hole for air injection in the manifold?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Y8 Manifold Swap Page &raquo;</TD></TR><TR><TD CLASS="quote">Note the air injection on the flange....this will have to be plugged, or you will have a big vacuum leak. Sorry about the shitty picture, when I find a better one I will replace it.
</TD></TR></TABLE>


Modified by dr_latino999 at 8:05 PM 1/21/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by dr_latino999 &raquo;</TD></TR><TR><TD CLASS="quote">NEWSFLASH~~~Does your Y8 Manifold have the hole for air injection in the manifold?

</TD></TR></TABLE>


we have found the winner

 

Damn I wish that was my problem.

My intake mani doesn't have that air induction hole.

Here's a few pics:









Even though everything is disconnected in the pics, I had them connected before when I was starting the car up.

I labeled the connections as to how I did them, if anyone notices anything wrong please let me know.

The ones not labeled are:
MAP vaccuum from control box on firewall to small nipple on the back of the mani
Charcoal cannister to top of throttle body
Purge cut off (I believe) from throttle body to control box on firewall

I am not using fast idle or egr.

NOTE: on these pictures I just took the mani off so I haven't cleaned any of the surfaces yet.

Should I just go out and buy a new gasket and clean it all off really well and cross my fingers or is something else the culprit?

Thanks again Honda-Tech!!

 

Also the intake manifold gasket I bought was for a D16Z6, could this be the problem? The gasket still looks good, but you never know.

Man I am finally done with my swap and I was hoping to be able to take it out for the first time and see the difference, but I have to wait!!

going from 62 hp--&gt; 135-140 hp + lightened flywheel and Si tranny in a car that weighs less than 2000lbs should be fun!

 

a friend had a prob like this not long ago and it was a leaking tb gaskett might try that is you havent already...

 

A guy i know explained this same exact problem to me about his JDM D15b swap. I havent gone to go look at it, but i know he hasnt fixed it yet. His car still sits there. I wanna see where this thread goes...

 

Damn that's shitty both of our motors are doing this. What IM and gasket was he using?

Here's my setup one more time in case I forgot something before:
91 HF
91 D15B OBD1 longblock made to run with OBD0 PS9 computer (HF dist, injectors, 02 sensor)
99-00 Si CAI
B18A1 TB (old gasket)
D16Y8 IM (kinda old z6 gasket
Lightspeed header
New spark plugs and wires
B&M adjustable FPR and gauge
ZEX ~6 lb flywheel
91 Si tranny

I replaced the rear main seal, oil pan seal, timing belt, water pump, practically every hoses and clamps, fuel filter, oil filter, axles, maybe more.

I also removed all the AC components when I started the swap if that could do anything.

When I went out today to get the intake manifold gasket and throttle body gasket... I was going to get the D16Y8 (96 Civic EX -- don't get 99/00 Civic EX cause of previously mentioned "air induction" hole )im gasket and the B18A1 (91 LS) tb gasket, but they (kragen, autozone, pep boys) didn't have any in stock so I'm going to check Honda/Acura and some other places tomorrow before work. Hopefully I can get this running soon, school just started.

Would the Y8 im gasket be the right one and Z6 not work (P08 head on the D15B is the pretty much same as Z6 so I got that one first but I'm using the Y8 mani so would it be the gasket of the mani, not the head?)

The TB gasket was the only gasket that was not replaced, I got the one I'm using used with the TB assuming it was the right gasket for the TB and also several people told me you can re-use TB gaskets so it might be messed/wrong. However I also torqued my im gasket and re-used it -- was leaking coolant from there so I had to scrape the rest of the old gasket I missed off.

I also have the Helms in front of me if anyone wants to see the page about how I did all the vaccuum connections and what not.

CLIFFS/SPARKS: Gonna replace im gasket w/ new y8 one, get new b18a1 tb gasket (and make sure it's the right one) and hopefully it will stop the HUGE air leak

Thanks a lot guys for helping me out with this, it's my first swap and none of my family thought I would be able to do it.


Modified by whizdumb at 6:49 AM 1/22/2005

 

go to napa,it will be cheaper and you wont have to wait as long.my store can usually get any part the next day or 2 days tops.

 

i dont have a tb gasket on my y8 manifold and my car idles at 800 .

 

I did this exact swap a couple years ago. Exact same problem. I had somehow wired the iacv wire to a different wire. (Both were blue wires on same main connector.) Try unplugging your air valve. If the engine reduces RPM or stalls i'd say the problems either within the air valve or wiring. You can always just unplug the iacv and eacv and work your thottle pedal like a mother to keep it alive, like I did when I just HAD to drive it! Damn fun car though for the bucks! Just got a second EF hatch will be swapping in a b18. Should be more fun

 

man i have this same problems right now, my rpms wont drop below 4000rpms....

let me know when you figure out!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by m3dia_lab &raquo;</TD></TR><TR><TD CLASS="quote">man i have this same problems right now, my rpms wont drop below 4000rpms....

let me know when you figure out!</TD></TR></TABLE>

I think the key detail is the car revs as high as it can go before u shut it off. I dont think it holds a steady high idle rpm. Am i right original poster (whizdumb) ?

 

i swaped a B18a1 into my CRX hf and have had one problem after another,I got it somewhat fixed,It was the throttle cable and the little idle choke thing on the throttle body....I have solved most of my problems w/ a Civic Si(88-91) Map sensor set up,easy to do and only about $40 and 1 hour....

 

He's my solution.

Plug the air injection holes.

New O.E.M ls tb gasket.

New O.E.M y8 intake manny gasket.

Friend did the swap without any problems.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by -16V- &raquo;</TD></TR><TR><TD CLASS="quote">He's my solution.

Plug the air injection holes.

New O.E.M ls tb gasket.

New O.E.M y8 intake manny gasket.

Friend did the swap without any problems. </TD></TR></TABLE>

I don't have any air injection holes to plug (I'm using 96-97 IM).

Got new OEM LS TB and Y8 IM gaskets, gonna put them on tomorrow.

Hopefully this will fix everything..

The throttle cable was totally unhooked from the throttle body when it was doing this so it couldn't be the cable. However it did seem like there was a little extra room between the throttle body plate and the inside diameter of the throttle body.

I might try my old HF TB if it still does this after the new gaskets.

Oh yeah I did leave my car on for a while to let it run and see if it would drop and for the few seconds it was on it seemed to stabilize around 4k rpm, but I was scared it was gonna do something so I shut it off.

 

Also on my pictures above I labeled the EACV/IACV MAP for some reason...

My MAP sensor is still on the firewall in the control box so there's no way I could have crossed it with the TPS.

I have the Helms diagrams for the vaccuum lines (for '91 only) if anyone wants to see them. Or if you have them for a D16Y8, let me know too.

 

Do you have cruise control? If not, make sure you plug the nipple on the back side of the IM.