Question about Long term fuel trims


	Auto Repair Home	SEARCH POSTS	WHO'S ONLINE	LOG IN

Automotive Repair

Car Troubleshooting Topics
  Car Troubleshooting
  Engine Troubleshooting
  Engine Fault Codes
  Electrical and Wiring
  Transmission Problems

Car Repair Topics
  Car Making Noises
  Car Stereo Repair
  Heating or AC Issues
  Motorcycles and ATVs
  Tricks of the Trade
  Truck Repair Advice

Site Options:
  Login
  Sign up here!

Latest Forum Post

2006 Toyoto Camry XLE Driver Side Electric Window Trouble

Hello, Looking for a little brain help ...

Tierod end change caused some kind of leak

Hello so I just took my car to the nearb...

2011 Dodge Nitro OBD scanner seems to drain battery in 10-20 minutes

When I bought this car in summer 2023, a...

Grounding Cable, 2017 Jeep Renegade Trailhawk

The Cable that connects my negative batt...

Rough Idle (Found new thing)

Hi everyone. First of all sorry for bad ...

equipment

hey yall. im a first year engineering st...

HELP

I have a 1956 1/2 ton panel truck, 69 35...

Howdy

    Just wanted to s...

ABS/Tractiob/Brake Lights on But No DTCs

Hello all, Recently while driving m...

Chevy strut replacement

I'm trying to get a sensor of some kind ...

Question about Long term fuel trims

Sign up here!

Email This Post

Auto Repair Home>> Automotive Repair>> Car Troubleshooting

Amjadov
New User

Nov 15, 2021, 12:21 AM

Post #1 of 4 (636 views)

Question about Long term fuel trims	Sign In

I understand that when the long fuel trim line is high on the positive side (+21 in my case) it means that there is too much air going into the engine and the ECU is compensating by adding more fuel, but what does it mean when one of the fuel term trim lines is normal (around 0) and the second long term fuel line is +21 ?

My car is 2007 ford explorer sport trac 4.0L V6

btw there are no error codes and the check engine light is off.

Thanks.

Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Nov 15, 2021, 4:54 AM

Post #2 of 4 (613 views)

Re: Question about Long term fuel trims	Sign In

That means one bank is reading richer than the other.

That could mean a vacuum leak on the side reading positive

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.

Amjadov
New User

Nov 15, 2021, 5:13 AM

Post #3 of 4 (609 views)

Re: Question about Long term fuel trims	Sign In

In Reply To

That means one bank is reading richer than the other.

That could mean a vacuum leak on the side reading positive

You mean there are separate air lines to each bank?

Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Nov 15, 2021, 6:18 AM

Post #4 of 4 (603 views)

Re: Question about Long term fuel trims	Sign In

No, but things are not duplicated to balance. Some things are on one side of the engine and other things are on the opposite side. There is also an intake manifold gasket on both sides.

I would suggest having a smoke test done to find any leaks.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.

Email This Post

Search for (options) Privacy Sitemap