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

86 Iroc Maf Problem

Thread Tools
 
Search this Thread
 
Old 09-11-2012, 10:41 AM
  #1  
Junior Member
Thread Starter
 
3rdgencamaro10's Avatar
 
Join Date: Mar 2008
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
86 Iroc Maf Problem

I replaced the burn off relay, and the maf. I'm not getting a check engine light, but if I unplug the maf burn off relay the car runs smoother. However when I plug it in, it begins running rough and rich. Any help would be appreciated.
Old 09-11-2012, 01:54 PM
  #2  
Supreme Member

iTrader: (2)
 
hellz_wings's Avatar
 
Join Date: May 2007
Location: Montreal, Canada
Posts: 2,337
Received 1 Like on 1 Post
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: 86 Iroc Maf Problem

What would help us is to know what mods you've done to your car, engine, intake, internal, fuel, etc.. Running smoother could mean alot of things.
Old 09-13-2012, 07:33 AM
  #3  
Junior Member
Thread Starter
 
3rdgencamaro10's Avatar
 
Join Date: Mar 2008
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Re: 86 Iroc Maf Problem

Engine is a 305, and by smoother I mean it's not coughing out black smoke(running rich) and stuttering when idleing. But it only runs rich and stutters with the maf burnoff relay plugged in.
Old 09-13-2012, 09:41 AM
  #4  
Supreme Member

iTrader: (2)
 
hellz_wings's Avatar
 
Join Date: May 2007
Location: Montreal, Canada
Posts: 2,337
Received 1 Like on 1 Post
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: 86 Iroc Maf Problem

Mods done to your car?
Old 09-13-2012, 02:25 PM
  #5  
Junior Member
Thread Starter
 
3rdgencamaro10's Avatar
 
Join Date: Mar 2008
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Re: 86 Iroc Maf Problem

I bought the car a few months ago so far from the previous owners, Smog pump has been removed and cat too, the fuel lines in the back by the tank were replaced with high pressure hoses, i've been told it's been sitting in a garage for a while, and the wiring harness looks like someone's been in there.
Old 09-13-2012, 03:31 PM
  #6  
Supreme Member

iTrader: (2)
 
hellz_wings's Avatar
 
Join Date: May 2007
Location: Montreal, Canada
Posts: 2,337
Received 1 Like on 1 Post
Car: 1986 Chevrolet Camaro IROC-Z28
Engine: TPI 310ci (LB9)
Transmission: Custom Rebuilt 700R4 - 2600 Stall
Axle/Gears: 10 bolt, 3.73 Eaton Limited-Slip
Re: 86 Iroc Maf Problem

Chances are the cat was removed because it was clogged or damaged from running too rich (black smoke you were talking about). Without a cat the smog pump is useless so that's why that is gone.. I don't understand what you mean by high pressure hoses.. Either way you have to fix the rich problem and it seems to be the MAF causing this problem.

You said that you replaced the MAF - What did the car do before you replaced the MAF? For the most part it does not need to be replaced unless it's damaged for some reason.
Old 09-14-2012, 07:09 AM
  #7  
Junior Member
Thread Starter
 
3rdgencamaro10's Avatar
 
Join Date: Mar 2008
Posts: 4
Likes: 0
Received 0 Likes on 0 Posts
Re: 86 Iroc Maf Problem

The car idled higher without the maf replaced but it didn't run rich.
Old 09-14-2012, 07:19 AM
  #8  
Supreme Member

iTrader: (1)
 
ibmtech's Avatar
 
Join Date: Oct 2005
Location: Glen Park, NY
Posts: 1,050
Likes: 0
Received 0 Likes on 0 Posts
Car: 1987 IROC-Z
Engine: TPIS II Supercharged w/Nitrous
Transmission: 700R4 Probuilt
Axle/Gears: 3:73 Richmond 12 Bolt
Re: 86 Iroc Maf Problem

Doesn't the burn off relay only work before the engine is running to superheat the element inside of it then stops working and the MAF power relay takes over?
Old 09-14-2012, 09:03 AM
  #9  
Junior Member

 
camarorookie's Avatar
 
Join Date: Dec 2004
Posts: 84
Likes: 0
Received 1 Like on 1 Post
Re: 86 Iroc Maf Problem

The MAF burn off circuit cycles for a few second after the ignition is turned off. The MAF measures air flow by providing voltage to the MAF sensor, heat, then as the air passes over the sensor it cools it and changes the voltage. The ECM converts this voltage to grams per second of air flow. If the burn off circuit is energized this would definitely through off this calculation.
The burn off cycle super heats the MAF sensor to burn off any contaminates that might have accumulated during operation, but only for a few seconds after the ignition is turned off. You should be able to look inside the MAF and see the sensor wires glowing red hot if the circuit is energized.
Are you sure it's the burn off relay you are unplugging and not the MAF relay? It wouldn't be the first time a new MAF failed right out of the box. Start your car and unplug the connector at the MAF and see if you have the same results.
Old 07-17-2017, 06:20 PM
  #10  
Sponsor

iTrader: (92)
 
Tuned Performance's Avatar
 
Join Date: Dec 2004
Location: Mile High Country !!!
Posts: 15,408
Received 656 Likes on 580 Posts
Car: 1967 Camaro, 91 z28
Engine: Lb9
Transmission: M20
Axle/Gears: J65 pbr on stock posi 10bolt
Re: 86 Iroc Maf Problem

Sounds like you have covered it all.
If you look at your memcal and it says aum. It's known to have maf issues and can be updated
http://www.gmtips.com/3rd-degree/dox/tips/ecm/prom.htm
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
86IROC112
Engine/Drivetrain/Suspension Wanted
7
09-07-2015 01:37 PM
NBrehm
Engine/Drivetrain/Suspension Parts for Sale
1
08-25-2015 11:49 PM
nuggie
DFI and ECM
3
08-25-2015 01:27 PM
perZ
TPI
7
08-15-2015 01:17 PM
mustangman65_79
Body
3
08-11-2015 03:17 PM



Quick Reply: 86 Iroc Maf Problem



All times are GMT -5. The time now is 08:21 PM.