TPI Tuned Port Injection discussion and questions. LB9 and L98 tech, porting, tuning, and bolt-on aftermarket products.
Sponsored by:
Sponsored by:

91 tpi O2 issue

Thread Tools
 
Search this Thread
 
Old 11-27-2023, 07:23 AM
  #1  
Junior Member
Thread Starter
 
Faolan's Avatar
 
Join Date: Sep 2016
Posts: 78
Received 1 Like on 1 Post
91 tpi O2 issue

Car runs good and has great power, new O2 plugs wire cap dostributor and new intake gaskets.

issue is when it hits closed loop it's apparently running extremely rich so it pulls fuel and starts missing sometimes lean surge etc. still runs great when I'm actually driving thought. at idle and very low rpm cruise I'm seeing 108 blm and 97-116 int while occasionally missing

no codes,

unplugged O2 no problems no codes. should set a code correct? Bad ecm maybe? Just looking for suggestions before I buy injectors (pretty sure they're original) all sensor values seem in spec and okay from what I've gathered.
Old 11-27-2023, 07:35 AM
  #2  
Senior Member

 
Aaron R.'s Avatar
 
Join Date: Oct 2004
Location: Missouri
Posts: 833
Received 198 Likes on 134 Posts
Car: 1985 Z28
Engine: 305 LG4
Transmission: T5
Axle/Gears: 3.42
Re: 91 tpi O2 issue

If you think your injectors are original dig into that to verify. If so, almost certainly bad. I went with Southbay and am very happy with them.
Old 11-27-2023, 08:32 AM
  #3  
Junior Member
Thread Starter
 
Faolan's Avatar
 
Join Date: Sep 2016
Posts: 78
Received 1 Like on 1 Post
Re: 91 tpi O2 issue

How do I check if they're original? I'll post a pic of them after work. They're grey if that matters
Old 11-27-2023, 12:07 PM
  #4  
Sponsor
 
southbay08's Avatar
 
Join Date: Nov 2008
Location: Rockville Centre, NY
Posts: 1,491
Received 33 Likes on 27 Posts
Re: 91 tpi O2 issue

either send a pic or give me the part number off of the injector. I'll let you know if they are stock
Old 11-27-2023, 12:14 PM
  #5  
Junior Member
Thread Starter
 
Faolan's Avatar
 
Join Date: Sep 2016
Posts: 78
Received 1 Like on 1 Post
Re: 91 tpi O2 issue

Originally Posted by southbay08
either send a pic or give me the part number off of the injector. I'll let you know if they are stock
didn't see the part number, here's a couple pics


Old 11-27-2023, 12:18 PM
  #6  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,464
Received 674 Likes on 595 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 91 tpi O2 issue

Definitely a problematic multec injectors
The following users liked this post:
MikeKy (11-28-2023)
Old 11-27-2023, 12:57 PM
  #7  
Junior Member
Thread Starter
 
Faolan's Avatar
 
Join Date: Sep 2016
Posts: 78
Received 1 Like on 1 Post
Re: 91 tpi O2 issue

Thanks for the confirmation, I'll get a set ordered and see how it goes
Old 11-27-2023, 03:58 PM
  #8  
Sponsor
 
southbay08's Avatar
 
Join Date: Nov 2008
Location: Rockville Centre, NY
Posts: 1,491
Received 33 Likes on 27 Posts
Re: 91 tpi O2 issue

Yup...those are the originals....as tuned performance mentioned...extremely problematic!!!
Old 11-27-2023, 07:03 PM
  #9  
Moderator

 
Vader's Avatar
 
Join Date: Jan 2000
Posts: 19,369
Received 219 Likes on 179 Posts
Re: 91 tpi O2 issue

Most of those Multecs did their job successfully - They lasted through the warranty period. The prior version RP/Bosch injectors seemed to be a lot more reliable in the long term.
Old 11-28-2023, 02:11 PM
  #10  
Junior Member
 
MikeKy's Avatar
 
Join Date: Feb 2023
Location: Mt Washington KY
Posts: 47
Received 3 Likes on 3 Posts
Car: 1955 Chevy Belair
Engine: 87 L98 from Corvette converted SD
Transmission: 700R4
Axle/Gears: 3.08 POSI
Re: 91 tpi O2 issue

Just put Southby in mine and they are great.
Old 12-02-2023, 03:51 PM
  #11  
Junior Member
Thread Starter
 
Faolan's Avatar
 
Join Date: Sep 2016
Posts: 78
Received 1 Like on 1 Post
Re: 91 tpi O2 issue

Thanks South Bay, had 3 bad on drivers side according to the ohms, car runs good at idle and great everywhere else WITH the o2 unplugged. Still get the same symptoms as before when it's plugged in. This is anew sensor

can anyone link me the best single wire o2 for this car? Thanks in advance
The following users liked this post:
SbFormula (12-03-2023)
Old 12-03-2023, 07:28 AM
  #12  
Supreme Member

 
SbFormula's Avatar
 
Join Date: Jun 2012
Location: Canada
Posts: 1,241
Received 152 Likes on 125 Posts
Car: '91 Firebird Formula
Engine: SP383 Deluxe FIRST® TPI Intake
Transmission: Tremec T56
Axle/Gears: Moser 9" Eaton Truetrac Motive 3.89
Re: 91 tpi O2 issue

I think anyone who still have those should just change them no matter what lol

I'm guilty of it. Have an '89 IROC-Z all original low milage with them on. Runs great! I also have a new set for it but too lazy to swap them, waiting for them to fail I guess.



Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
m300slr
DIY PROM
13
01-02-2023 01:14 PM
liquidh8
DIY PROM
20
04-22-2007 10:26 PM
trigger GTA
DIY PROM
5
05-21-2003 04:20 AM
gta324
DIY PROM
4
11-21-2002 09:33 PM
2QUIK6
TPI
5
09-26-2002 09:55 PM



Quick Reply: 91 tpi O2 issue



All times are GMT -5. The time now is 02:40 AM.