lean codes 41,91 yet burning very rich??
Forums at Modded Mustangs
Home Register FAQ Members List Calendar Blogs Garage Gallery Search Today's Posts Mark Forums Read Insurance


Go Back   Forums at Modded Mustangs > Mustang Forums > 5.0 Mustangs

ModdedMustangs.com is the premier Ford Mustang Forum on the internet. Registered Users do not see the above ads.
Reply
 
LinkBack Thread Tools
Old July 3rd, 2009, 04:36 PM   #1
Regular
 
1989 LX coupe
 
Join Date: Jul 2009
Location: calgary
Posts: 79
calgarynotch is on a distinguished road
iTrader: 0 reviews
Default

lean codes 41,91 yet burning very rich??


ever since i got my car it has had tons of problems with stumbling idle and rich condition so i cleaned the idle controller,cleaned the air temp sensor,cleaned the maf, replaced the coolant sensor, replaced both o2's, set the timing to 12', resealed the upper and lower intake (typhoon) cleaned the contacts on the salt and pepper shaker plugs, reset base idle, reset tps to .93 and after all that i never got an engine light yet it was still rich. now after removing the a.i.r. solenoids and switches and a bunch of vacuum lines, as well as no apparent leaks im getting codes 41 and 91. along with the 33 egr fail code which ive been told wont affect drivability. the egr is still hooked up. but it will burn through a tank of fuel so fast that its getting almost annoying. i pulled the plugs and i can tell its running rich. very little brown on the plug. it has headers no cats and a few other things done.

can someone please tell me why it can be blowing faint black smoke out when i stomp on it then throw a lean code when i run it through the gears? even at idle its got a very gassy smell. and im not sure if its the tilted angle of the exhaust or the magnaflows but there is no condensation coming out the exhaust.

sorry for the heavy post but any help would be well appreciated
  Reply With Quote
Sponsored Links
Advertisement
 
Old July 3rd, 2009, 08:39 PM   #2
Regular
 
1989 LX coupe
 
Join Date: Jul 2009
Location: calgary
Posts: 79
calgarynotch is on a distinguished road
iTrader: 0 reviews
Default

anyone?

im leaning to bad wires or maybe fpr. it has a stock fuel pump also. im not sure if i need to upgrade
  Reply With Quote
Old July 3rd, 2009, 09:01 PM   #3
MM Ninjas!
 
1slo5.0's Avatar
 
1990 Mustang LX
9.36@143 mph
 
Join Date: Jan 2006
Location: North Fond du Lac, Wisconsin
Posts: 11,375
1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all
iTrader: 1 reviews
Send a message via AIM to 1slo5.0
Default

- Check to make sure the Oxygen sensor ground wire is still attached to the firewall and has a good, clean connection. This is an orange wire that comes out of the engine wiring harness and attaches to the firewall.

- Check for vacuum leaks. The 41 and 91 codes can be caused by a vacuum leak. Being that you have one of those chinese intakes, a vacuum leak is very possible.

- Do you have a stock mass air flow sensor?

- What is the fuel pressure at?

The system detects the lean condition and dumps more fuel in which is why it is running rich now. That is normal. That is the computer protecting your engine.
__________________
My daily driver has 16 cylinders and 4400hp @ 1000 rpm....


***1988 Mustang GT - Stock....almost
  Reply With Quote
Old July 4th, 2009, 12:42 AM   #4
Regular
 
1989 LX coupe
 
Join Date: Jul 2009
Location: calgary
Posts: 79
calgarynotch is on a distinguished road
iTrader: 0 reviews
Default

I have no idea what the fuel psi is. I think its time for an adjustable regulator with guage for sure. The maf is stock. And idk I'm pretty sure I don't have any vacuum leaks.it has all new gaskets. And I put a nice fat bead of silicone between the upper and lower. I'm stumped
  Reply With Quote
Old July 4th, 2009, 12:58 AM   #5
MM Ninjas!
 
1slo5.0's Avatar
 
1990 Mustang LX
9.36@143 mph
 
Join Date: Jan 2006
Location: North Fond du Lac, Wisconsin
Posts: 11,375
1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all
iTrader: 1 reviews
Send a message via AIM to 1slo5.0
Default

Originally Posted by calgarynotch View Post
I have no idea what the fuel psi is. I think its time for an adjustable regulator with guage for sure. The maf is stock. And idk I'm pretty sure I don't have any vacuum leaks.it has all new gaskets. And I put a nice fat bead of silicone between the upper and lower. I'm stumped
New gaskets doesn't mean shit with that intake. Those chinese pieces of shit have the poorest machine work I've ever seen. Get yourself a can of carb cleaner and start spraying the mating surfaces of the intake. If the idle speed increases then you have found a vacuum leak.

If you have a friend with a Mustang see if you can borrow his MAF......just to rule your MAF out as the problem.
__________________
My daily driver has 16 cylinders and 4400hp @ 1000 rpm....


***1988 Mustang GT - Stock....almost
  Reply With Quote
Old July 4th, 2009, 01:53 PM   #6
Regular
 
1989 LX coupe
 
Join Date: Jul 2009
Location: calgary
Posts: 79
calgarynotch is on a distinguished road
iTrader: 0 reviews
Default

i think that's a good idea. i guess when the previous owner had the engine out a lot of the wiring wasn't put back in place properly and maybe that orange (bad color for a ground) is not hooked up right. could i have a leak at an injector hole? a few of them were pissing fuel before i pulled the intake off and turned and bolted them down better. where does the 02 sensor wiring route normally? and also does the little box that suppost to be on the firewall have to be grounded? cause its just laying there behind the intake right now.

sometimes it weird how my car will intermittently pull alot harder like when im driving on a rough calgary road downtown and mash on it. im also wondering if my maf is too small for my mods and if i should upgrade to a bigger fuel pump?
  Reply With Quote
Old July 5th, 2009, 11:33 AM   #7
MM Ninjas!
 
1slo5.0's Avatar
 
1990 Mustang LX
9.36@143 mph
 
Join Date: Jan 2006
Location: North Fond du Lac, Wisconsin
Posts: 11,375
1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all
iTrader: 1 reviews
Send a message via AIM to 1slo5.0
Default

Originally Posted by calgarynotch View Post
i think that's a good idea. i guess when the previous owner had the engine out a lot of the wiring wasn't put back in place properly and maybe that orange (bad color for a ground) is not hooked up right. could i have a leak at an injector hole? a few of them were pissing fuel before i pulled the intake off and turned and bolted them down better. where does the 02 sensor wiring route normally? and also does the little box that suppost to be on the firewall have to be grounded? cause its just laying there behind the intake right now.

sometimes it weird how my car will intermittently pull alot harder like when im driving on a rough calgary road downtown and mash on it. im also wondering if my maf is too small for my mods and if i should upgrade to a bigger fuel pump?
The orange wire normally connects to the firewall or to one of the cylinder heads or intake.

I'm not sure what little box you are talking about. Can you take a picture?

The stock MAF is too small for the stock engine. It is a beneficial to upgrade.
__________________
My daily driver has 16 cylinders and 4400hp @ 1000 rpm....


***1988 Mustang GT - Stock....almost
  Reply With Quote
Old July 5th, 2009, 11:58 AM   #8
aka Nature boy
 
sickfox's Avatar
 
blk 89/red 91 XJ Limited
I like turtles
 
Join Date: Jun 2009
Location: CLEVELAND OHIO
Posts: 8,565
sickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant futuresickfox has a brilliant future
iTrader: 3 reviews
Default

Originally Posted by 1slo5.0 View Post
The orange wire normally connects to the firewall or to one of the cylinder heads or intake.

I'm not sure what little box you are talking about. Can you take a picture?

The stock MAF is too small for the stock engine. It is a beneficial to upgrade.
anything else required to do when u upgrade the maf? or no?
__________________
<img src=http://i7.photobucket.com/albums/y259/Thurston22782/siggg.png border=0 alt= />

Black Stang Crew Founder #-1

MM+Cleavage Club #15
www.xjor.org

Originally Posted by TheUNZippee! View Post
I would drag my dick through a mile of broken glass just to hear her fart through a walkie talkie
  Reply With Quote
Old July 5th, 2009, 12:05 PM   #9
MM Ninjas!
 
1slo5.0's Avatar
 
1990 Mustang LX
9.36@143 mph
 
Join Date: Jan 2006
Location: North Fond du Lac, Wisconsin
Posts: 11,375
1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all1slo5.0 is a name known to all
iTrader: 1 reviews
Send a message via AIM to 1slo5.0
Default

Originally Posted by turbofoxbody View Post
anything else required to do when u upgrade the maf? or no?
No.
__________________
My daily driver has 16 cylinders and 4400hp @ 1000 rpm....


***1988 Mustang GT - Stock....almost
  Reply With Quote
Old July 5th, 2009, 10:14 PM   #10
Regular
 
1989 LX coupe
 
Join Date: Jul 2009
Location: calgary
Posts: 79
calgarynotch is on a distinguished road
iTrader: 0 reviews
Default

Well that ground wasn't hooked up so I hooked it up and noticed its not as rich and its only throwing the 33,41,91 codes for egr and a.I.r.which isn't hooked up. It still blows a small amount of black when I stomp on it...I'm pretty sure it shouldnt do that. It seems to be lacking a little as well
  Reply With Quote
Sponsored Links
Advertisement
 
Reply

Thread Tools


Threads Similar to: lean codes 41,91 yet burning very rich??
Thread Thread Starter Forum Replies Last Post
Rich and lean at the same time? baine21225 5.0 Mustangs 8 April 7th, 2009 03:18 PM
Car Running rich or lean?? dgt_mustang V6 Mustangs 5 November 28th, 2008 05:05 PM
miss,lean or rich? 88stang 5.0 Mustangs 0 July 17th, 2008 12:31 AM
Fuel Problems Burning Rich / Burning Lean Steves LX 5.0 Mustangs 5 March 21st, 2007 10:46 PM
Need Help Burning Very RICH!!!! giddyup91 5.0 Mustangs 7 December 1st, 2006 03:44 PM



All times are GMT -4. The time now is 09:03 AM.
Modded Mustangs is ©2005-2008, All Rights Reserved, And is Not Affiliated with Ford Motor Company.
Forum is powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd. & SEO by vBSEO 3.3.2 ©2009, Crawlability, Inc.

powered by vBulletin ©2000 - 2012, Jelsoft Ent. Ltd.