The idle on my hatch is sporadic, from 3000-1000rpm, over and over. Sometimes it holds 2500RPM for about 2-3 secs. The engine has no vacumm leak. I cannot feel/hear any leaking. I'm replacing the PCV for kicks incases its cracked. Any other ideas? It's an LS swap with most of the vacumm stuff removed. Only MAP, fuel pressure and pcv are on vacumm. Everything else has been removed (how I got the engine).

Edit: Additional info

B18A1
Civic Cx
Obd1 Convertion. OBD2 Dizzy
No CEL, only code is 20 (due to bad ground being fixed soon enough)
Dizzy is a VTEC dizzy, might be an issue I know
TPS is not calibrated, being done so tonight.


Modified by ludesrv at 10:15 AM 1/2/2007

 

Checking the TPS voltage is a good starter (like you said). This sounds similar to an EACV/IACV problem. You say that most of the vaccuum stuff is gone, did this get removed as well? If not I'd say it's worth checking out.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">Checking the TPS voltage is a good starter (like you said). This sounds similar to an EACV/IACV problem. You say that most of the vaccuum stuff is gone, did this get removed as well? If not I'd say it's worth checking out.</TD></TR></TABLE>

I was thinking IACV but I'm not getting code 14 so I don't know if it's worth pulling off and cleaning.

The peice to help it idle from factory on the LS have been removed before I bought the engine. The engine idled fine, not sporadic, before I put the TPS on, and now it's crazy. But for me to do it I had to remove the TB to replace it (snapped on the way into the bay, my bad). I'm starting to lean on the TPS. Will a horribly calibrated TPS cause jumping idle? I've seen some way off and they just made it idle high, not sporadic like mine.

 

Yes a miscalibrated TPS can cause a high idle, not sporadic. Since your idle is around 3K-1K this seems to be a likely problem. I'd say it's worth cleaning out your EACV and TB while you're at it and doubl-checking for any vaccuum leaks. Or the EACV could be malfunctioning and not giving a CEL, that's what happened to me recently.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">Yes a miscalibrated TPS can cause a high idle, not sporadic. Since your idle is around 3K-1K this seems to be a likely problem. I'd say it's worth cleaning out your EACV and TB while you're at it and doubl-checking for any vaccuum leaks. Or the EACV could be malfunctioning and not giving a CEL, that's what happened to me recently.</TD></TR></TABLE>

I'll pull it off tonight and shoot some brake clean at it. It's only 2 screws if you don't undo the cooling system. The sporadicness also starts approx. 30 seconds after startup. Anything before that it's mint. Also, I beleive my thermostat is stuck open (doesn't heat up very well, showing all the classic thermostat symptoms), would that make IACV read incorrectly? It get's warm, just never at full operating temp.

 

also check your coolant level and make sure you have no air pockets in the cooling system.. if you get air in the IAC it will idle like that

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by crx_pimp &raquo;</TD></TR><TR><TD CLASS="quote">also check your coolant level and make sure you have no air pockets in the cooling system.. if you get air in the IAC it will idle like that</TD></TR></TABLE>

It's been bleeded over and over for over 1 hour at once. I'm 100% sure there is no air bubbles.

 

ive had this same problem for a loong time but ive never gotten around to really digging into it.
I took my iacv off and cleaned it, but that didnt help much.
maybe i should try bleeding the coolant.

Keep us updated on your progress.

 

Well, the stuck open thermo may be responsible for some problems, as the coolant temp. determines whether or not the EACV is open or closed. Plus, it wouldn't hurt to put a new thermo in, especially because it's January .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">Well, the stuck open thermo may be responsible for some problems, as the coolant temp. determines whether or not the EACV is open or closed. Plus, it wouldn't hurt to put a new thermo in, especially because it's January .</TD></TR></TABLE>

Ya I know I should replace it. It's on my list of things to do.

 

Well for those wondering, I figured it out last night.

I replace the TB gasket, nothing, fast idle air, nothing, idle air valve, nothing. I went as far as putting on all new vaccumm hosing. I had it idling sporadically between 1000-1200 RPM and it was very annoying. I then busted out my volt meter and adjusted my TPS, nothing, timed the car, nothing. Replaced the PCV valve, nothing. It was very annoying. I even went as far as hot gluing my idle air valve so it would not move, and it still wouldn't run right, not throwing any codes. Last ditch attempt I found that my idle air wasn't getting proper voltage. I decided my wiring harness was getting old and cracking so I replaced the wire with a quick fix, nothing.

I then turned and looked, at my OBD1 F22 ecu. I replaced it with a P06 and voila, idled like a champ. The car now creates to much damn vacumm its pretty crazy haha, but the problem wasn't vaccum, the F and H ecus in obd1 don't have the same pin out, or I should say, send the right ammount of voltages in wires to make it run right. After I swapped ECUs with a D series one, it ran perfect without a top.

Hope this helps you guys out.