86 Codes and IAC Quiz
Thread Starter
Team Owner
Joined: Jan 2003
Posts: 20,342
Likes: 264
From: Summerland B.C. Canada
86 Codes and IAC Quiz
Drove into the driveway and parked her. 5 min later i get in and she doesn't run. I can make her run fine by working the gas pedal. Check codes and found none. Thinking it's a TPS or IAC problem i push and wiggle the IAC connector and try restart. She fires right up and idles. It seems i found the problem but would't a bad connection at the IAC connector show a code ??
Thanks Again
Dan
:cheers:
Thanks Again
Dan
:cheers:
Team Owner
Joined: Sep 2001
Posts: 62,186
Likes: 1,741
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 86 Codes and IAC Quiz (AGENT 86)
Not necessarily. You can have sensors go out and not get any codes from them. A code 35 is a rare code to actually get.
- 1986 Original Owner -
Joined: Apr 1999
Posts: 3,193
Likes: 139
From: North Yorkshire, England
Cruise-In I Veteran
Cruise-In II Veteran
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VII Veteran
Re: 86 Codes and IAC Quiz (vader86)
A code 35 is a rare code to actually get.
Pro
Joined: Jun 2001
Posts: 511
Likes: 6
From: Edmonds WA
Re: 86 Codes and IAC Quiz (AGENT 86)
Sounds like you have the exact same behavior I did. I tried spraying cleaner into the TB, but that didn't help. It was an intermittent starting/idling problem and there were no codes. I finally took the TB off and completely apart and thoroughly cleaned it. The IAC valve was pretty cruddy, so I suspect that was the real problem... I think the pintel wasn't always seating properly... but the IAC seemed to be working right to the ECM.
I don't know, for sure, if the IAC was just dirty or going bad, because I replaced it. But since then I haven't had any starting or idling problems.
I'd recommend pulling the IAC out, at the very least, and cleaning it, if you don't mind the chance of having to take it all apart again. Even better would be to soak and clean the entire TB. If you want to avoid the risk of having to take it all apart again (in case cleaning the IAC doesn't work), replace the IAC (it's not that expensive a part).
You will need to adjust the TPS and the idle after you take the IAC out. See 65Z01's web page for some helpful info on how to do that.
Good luck! :cheers:
I don't know, for sure, if the IAC was just dirty or going bad, because I replaced it. But since then I haven't had any starting or idling problems.
I'd recommend pulling the IAC out, at the very least, and cleaning it, if you don't mind the chance of having to take it all apart again. Even better would be to soak and clean the entire TB. If you want to avoid the risk of having to take it all apart again (in case cleaning the IAC doesn't work), replace the IAC (it's not that expensive a part).
You will need to adjust the TPS and the idle after you take the IAC out. See 65Z01's web page for some helpful info on how to do that.
Good luck! :cheers:
Thread Starter
Team Owner
Joined: Jan 2003
Posts: 20,342
Likes: 264
From: Summerland B.C. Canada
Re: 86 Codes and IAC Quiz (K87ZZ4)
Thanks anyway K87ZZ4 but TB and IAC are both clean. My IAC connector has lost it's locking clips so bad connection caused the problem. I just wanted to know why no codes were set.
It sounds like a code 35 is as rare as 83 Corvette :D
Thanks :cheers:
It sounds like a code 35 is as rare as 83 Corvette :D
Thanks :cheers:
- 1986 Original Owner -
Joined: Apr 1999
Posts: 3,193
Likes: 139
From: North Yorkshire, England
Cruise-In I Veteran
Cruise-In II Veteran
Cruise-In III Veteran
Cruise-In IV Veteran
Cruise-In VII Veteran
Re: 86 Codes and IAC Quiz (AGENT 86)
It sounds like a code 35 is as rare as 83 Corvette :D
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 86 Codes and IAC Quiz (Ray Quayle)
I'll have to check in my helms manual for code 35.
If you take the IAC out, clean it gently, but don't fudge with it, it's quite fragile. And don't plug it in to the harness to test it externally.
Trust me on this. My knowledge derives from my infinite wisdom. :D
(well... actually I just broke mine, and had to fork up $35 for a new one.)
Pro
Joined: Jun 2001
Posts: 511
Likes: 6
From: Edmonds WA
Re: 86 Codes and IAC Quiz (AGENT 86)
Ahhhh... didn't realize you had already cleaned the TB and IAC. I hope the problem doesn't rear its ugly head again... that's what was so frustrating about mine... it happened so rarely.
FWIW, there is no code 35 listed in my 87 Service Manual.
FWIW, there is no code 35 listed in my 87 Service Manual.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
5 Best & 5 Worst Corvette Daily Drivers
Joe Kucinski
The Headlights of Every Corvette Generation Explained
Joe Kucinski
5 Best & 5 Most Overrated Corvette Track Packages of All Time!
Joe Kucinski
Every 2027 Corvette Engine Explained
Joe Kucinski
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Verdad Gallardo
10 Ugly Corvettes That We Still Kinda Love
Joe Kucinski
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 86 Codes and IAC Quiz (K87ZZ4)
i recall shopping for the iac, and the iac harness plug was a cheap part to get. i'm not sure if that was on one of the autozone/napa/kragen sites, or on zip-corvette.com where i saw it.
we also have this barnes/bowman distributors catalog at work, they liiterally have every auto manufacturer wiring plug, clip, and specialty screw known to mankind in tthere.
i'm not ssure if they have to be ordered in bulk or not though. i have a bunch of broken connectors on my car. pretty much all of em, except the maf and iac are broken!
we also have this barnes/bowman distributors catalog at work, they liiterally have every auto manufacturer wiring plug, clip, and specialty screw known to mankind in tthere.
i'm not ssure if they have to be ordered in bulk or not though. i have a bunch of broken connectors on my car. pretty much all of em, except the maf and iac are broken!
Pro
Joined: Jun 2001
Posts: 511
Likes: 6
From: Edmonds WA
Re: 86 Codes and IAC Quiz (CentralCoaster)
we also have this barnes/bowman distributors catalog at work, they liiterally have every auto manufacturer wiring plug, clip, and specialty screw known to mankind in tthere.
i'm not ssure if they have to be ordered in bulk or not though. i have a bunch of broken connectors on my car. pretty much all of em, except the maf and iac are broken!
i'm not ssure if they have to be ordered in bulk or not though. i have a bunch of broken connectors on my car. pretty much all of em, except the maf and iac are broken!
Can I just replace the plastic clip or do I have to splice in a new connector and clip?
Thread Starter
Team Owner
Joined: Jan 2003
Posts: 20,342
Likes: 264
From: Summerland B.C. Canada
Re: 86 Codes and IAC Quiz (K87ZZ4)
[Quote]Can I just replace the plastic clip or do I have to splice in a new connector and clip?
I'm sure some you can and some you can't.
Iv'e got a few broken ones than need replacement too.
I'm sure some you can and some you can't.
Iv'e got a few broken ones than need replacement too.
Team Owner
Joined: May 2002
Posts: 24,337
Likes: 25
From: San Diego , CA Double Yellow DirtBags 1985..Z51..6-speed
Re: 86 Codes and IAC Quiz (AGENT 86)
I'll steal the catalog from work and check it out. I know that Ecklers sells mostt of this stuff, and the dealership too, but I bet the distributors catalog would be wayyyy cheaper... but I may have to buy in bulk.
