Help with FJ62/3FE thats running rich... (1 Viewer)

Joined
Oct 25, 2008
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712
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Queen Creek, Az
Hello everyone.. Need some help for my son's FJ62 that he has had for about 5 mos now..
It has about 200,000+. The speedo gear was busted when we got it. So not sure what the actual mileage is...

Anyway, the PO advised that he had the CAT Converters replaced along with the 02 sensors prior to selling it for registration. When we got it we had to smog it again since we're the new owners, and it passed no problem....But lately the exhaust tip has been really 'SOOTY' and was running a little rich. I took it to a friends shop and they tuned it up, but they advised it is still running rich. They couldn't get the CATs to heat up to temp and think they might be no good again... I'm looking to you guys here on MUD (cuz we're still newbs) to find out what might be a common issue with these vehicles to have them run rich? I tried to research in the SEARCH function... but really didn't lead me too much with the 62, seems there are more issues with the carbed 60. Any experiances or help would be apprciated.

Recently done to try and remedy; New cap, rotor, plugs and plug wires. Also the shop cleaned up the air flow sensor but thats the extent of it.

Any help and advise would be greatly appreciated.

Scott
 
Joined
Apr 5, 2004
Messages
395
Location
San Antonio, TX
Check the wire that go to the O2 sensors. They might not be sending a signal, or the right signal. Could be faulty O2 sensors. Did you replace with quality O2 sensors? A lot of time the aftermarket sensors do not have the life of a factory replacement. Just a few ideas. good luck.
 
Joined
Oct 25, 2008
Messages
712
Location
Queen Creek, Az
Thanks... I was thinking that too.. would a faulty 02 sensor or wire throw the check engine light? Other than factory.. are the Bosch 02 sensors ok??

Any other thoughts on what else could cause the LC to run rich??

Thanks again,
 
Joined
Jul 15, 2007
Messages
335
Location
Houston, TX
The MAF/AFM can be adjusted to change the air/fuel mixture. You might look at the seal around the plastic cap to see if a PO or shop might have gone in there and made adjustments. You mentioned a shop went in and cleaned up the AFM. Would it be worth double checking the flapper is operating correctly and everything is plugged in right?

Minute Mod- Adjusting the Air Flow Meter

Adjusting the AFM should not be used to compensate for other problems but might be considered as a last resort.
 
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Wile E Coyote

Out in the streets, they call it murder!
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Sep 20, 2005
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Western AZ
If the ECU isn't sensing normal operating temp, it will keep the EFI in closed loop condition. Said another way, the ECU thinks the truck is still cold, therefore needing enrichment to aid atomization. Check the coolant temp sensor.
 
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Feb 21, 2006
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Winston Oregon
bosch is fine and yes it would throw a code
Thanks... I was thinking that too.. would a faulty 02 sensor or wire throw the check engine light? Other than factory.. are the Bosch 02 sensors ok??

Any other thoughts on what else could cause the LC to run rich??

Thanks again,
 
Joined
Feb 21, 2006
Messages
11,976
Location
Winston Oregon
that is where I would start............dont just look at the wire, pull and inspect cause they love to come undone at the plug

but lets see if your rig throws a code first

i cannot remember if that wire is bad if its a # 13 or code 51?
If the ECU isn't sensing normal operating temp, it will keep the EFI in closed loop condition. Said another way, the ECU thinks the truck is still cold, therefore needing enrichment to aid atomization. Check the coolant temp sensor.
 
Joined
Oct 25, 2008
Messages
712
Location
Queen Creek, Az
If the ECU isn't sensing normal operating temp, it will keep the EFI in closed loop condition. Said another way, the ECU thinks the truck is still cold, therefore needing enrichment to aid atomization. Check the coolant temp sensor.

I'll check that.. thanks everyone for the input and advice!
 

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