Honda Car Forum


Go Back   Honda Car Forum - Accord Parts Civic Tuning Acura Racing > Honda Acura > Honda 2

LinkBack Thread Tools Display Modes
  #1 (permalink)  
Old 16 May 2007, 01:19 pm
Posts: n/a
Default 91 Civic EACV questions/diagnosis

I have been having some idling problems and decided to check out the
EACV system on my 91 Civic HB. No ECU codes, car starts fine. The main
symptom was the drop in idle speed to 500rpm when the engine was cold
and I was braking. Symptom went away after the car warmed up.
Following the troubleshooting chart in my Helm's manual, I proceeded
as follows:
1- Checked the resistance across the terminals of the EACV. Got
12ohms, within spec.
2- No continuity between each terminal and body ground - as expected.
3- Valve clicks when battery voltage is applied across the terminals.
4- Turned the ignition on, checked the voltage across the connector.
There is 12V - not expected according to the manual since the ECU
should be suppling the ground when EACV is activated. Confirmed by
disconnecting the ECU harness that indeed ECU is suppling the ground.
5- Put in another ECU - still voltage at EACV when ignition is on.
6- Put in another EACV - same problem with idle
7- New vacuum lines, bled the coolant - same problem with idle.

Question: Is it true that there shouldn't be ground supplied to the
EACV while the car is not running? The car was cold when I did these
tests so is it possible that ECU checks the coolant temperature and
decides to engage the EACV even if the car is not running?
Any ideas?

Reply With Quote

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Debugging a Funny PGM-FI EACV Problem ('89 1.5) andrew m. boardman Honda 2 13 30 Aug 2016 05:18 pm
91 Civic EACV questions/diagnosis Honda 3 9 21 May 2007 10:26 pm
91 Civic EACV questions/diagnosis Sean Honda 3 0 16 May 2007 01:08 pm
94 Honda Civic -- a/c diagnosis? B~ Honda 2 2 11 Jun 2004 02:10 pm
Cleaning of EACV on 89 Legend? Acura God please comment. Mikey Acura 3 07 Sep 2003 09:17 am

All times are GMT -5. The time now is 12:06 pm.

Honda News | Autoblog
Powered by Yahoo Answers

Powered by vBulletin®
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO 3.6.0 PL2 © 2011, Crawlability, Inc. is not affiliated with Honda Motor Company in any way. Honda Motor Company does not sponsor, support, or endorse in any way. Copyright/trademark/sales mark infringements are not intended or implied.