Replacing IACV what else should I replace?
02-28-2017
#1
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 
Replacing IACV what else should I replace?
Hey guys first time posting here and new to site. Just bought a 97 Civic LX 5 speed with CEL ON FOR P0505. After doing research on site forum and other places it appears replacing the IACV is a good place to start. Is there anything else I should replace in the process? New lines? Also want to OHM out wires to ECM would anyone have wiring schematics?
Vehicle wants to drop RPM when starting out and tries to stall out at stop light especially with A/C on. Which is always because I live in Florida haha.
Edit: I work on Class 6-8 trucks so cars are a completely different world.
Vehicle wants to drop RPM when starting out and tries to stall out at stop light especially with A/C on. Which is always because I live in Florida haha.
Edit: I work on Class 6-8 trucks so cars are a completely different world.
Last edited by Inkedmechanic; 02-28-2017 at 08:53 PM. Reason: Add more info
02-28-2017
#2
Registered!!
Join Date: Jan 2017
Location: Napa California
Age: 35
Posts: 109
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
just got over the exact same thing and i threw 200$ at itin the end idk what it was but start small/simple.. i would check/replace pcv as well..kind of a forgotten part. if its bad when you try to shake it - no noise.. good = you'll hear a rattle like sound
02-28-2017
#3
OF top 99.5% creator (Formerly of the Puffinblunts variety)
Re: Replacing IACV what else should I replace?
Removing and cleaning IACV and throttle body is a better place to start. Could be a dirty IAVC screen (part of gasket). Clean TB is always good. Any spark plug fouling? Test /clean first...replace parts last option.
03-01-2017
#4
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
Alright that's where I'll start. Only reason I was going to replace it was because of cheap the part is. I was told everything had been recently replaced but have not fully checked myself. Wires appear new.
03-01-2017
#5
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
Just found paperwork in owners manual showing he just replaced IACV and had throttle body cleaned beginning of September. Also replaced TPS and PCV. Ive seen where you can install wrong IACV valve any other suggestions to look for? Going to pull it in shop after work tonight and see what I can find.
03-01-2017
#6
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
I was reading thru your issue as well. Found IACV TPS and PCV where all replaced around 4-5 months ago.
03-01-2017
#7
OF top 99.5% creator (Formerly of the Puffinblunts variety)
Re: Replacing IACV what else should I replace?
Read this: https://www.ericthecarguy.com/29-obd...function-honda
(copied and pasted): "Often times a short-circuit is the cause of an IACV problem, so it's a good idea to check the wiring harness first when diagnosing the problem."
More reading: https://www.autocodes.com/p0505_1997_honda_civic.html
Go to Ace hardware or Napa and buy a can of this: https://www.wd40specialist.com/products/contact-cleaner
spray it in (male/female) connector pins and on outside (insulator) of connectors and wiring. Also, manipulate connectors and harness with fingers to try and find a short.
Beyond that:
Is spark good?
Compression good?
Misfires?
Perform a power balance (drop) test.
Inspect for vacuum leaks.
Weak coil and/or igniter can cause idle issues too.
Air in coolant can cause idle issues...may need to bleed.
(copied and pasted): "Often times a short-circuit is the cause of an IACV problem, so it's a good idea to check the wiring harness first when diagnosing the problem."
More reading: https://www.autocodes.com/p0505_1997_honda_civic.html
Go to Ace hardware or Napa and buy a can of this: https://www.wd40specialist.com/products/contact-cleaner
spray it in (male/female) connector pins and on outside (insulator) of connectors and wiring. Also, manipulate connectors and harness with fingers to try and find a short.
Beyond that:
Is spark good?
Compression good?
Misfires?
Perform a power balance (drop) test.
Inspect for vacuum leaks.
Weak coil and/or igniter can cause idle issues too.
Air in coolant can cause idle issues...may need to bleed.
Last edited by Wankenstein; 03-01-2017 at 09:25 AM.
03-01-2017
#8
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
Yup I was going to test voltage and ohm out wires. Found wire diagram online for ECM plug. Going to spend Saturday after work throughly going thru motor and front end. Thank you for help. Luckily previous owner only went to one shop and kept all receipts too so I know what's been done.
03-01-2017
#9
Registered!!
Thread Starter
Join Date: Feb 2017
Age: 38
Posts: 10
Likes: 0
Received 0 Likes
on
0 Posts
Rep Power: 0 Re: Replacing IACV what else should I replace?
Those sites were very helpful! At least I understand what the IACV does now and why the car runs like crap. Hopefully this is the only problem with that car haha for now
03-02-2017
#10
OF top 99.5% creator (Formerly of the Puffinblunts variety)
Re: Replacing IACV what else should I replace?
I posted some vids related to tracking down vacuum leaks which may be related to your engine's issue. That guy (Rachets and Wrenches) has very good auto repair videos.
