Low Fuel Trim under load in B16 - Honda-Tech - Honda Forum Discussion

Honda Civic / Del Sol (1992 - 2000) EG/EH/EJ/EK/EM1 Discussion

Low Fuel Trim under load in B16

Old 08-12-2018, 02:45 PM
  #1  
Honda-Tech Member
Thread Starter
 
1999AZhatch's Avatar
 
Join Date: Jun 2018
Location: Tucson
Posts: 41
Default Low Fuel Trim under load in B16

hey guys, need to pick some brainz....

Iíve got a 99 dx hatch with a B16a, running an EM1 harness and ecu.

No dtc, but Iíve felt like the car was feeling slightly under powered in certain situations, I.e. under heavy acceleration in third or fourth. Almost that Ďbarely perceptible leaní misfire that only people like us would notice but not like a full on Ďdead cylinderí miss that is very noticeable.

Hooked up a scan tool:

everything looks normal during idle, LTFT is at like -3 to -1, not bad for a high mileage engine.

HOWEVER! Under acceleration, especially above 3500 rpm, stft drops to between -15 and -30. Itís trying to compensate for a supposedly rich condition and leaning way out.

is this normal?

what could be going on here? What are good things to check?

Last edited by 1999AZhatch; 08-12-2018 at 02:47 PM. Reason: Typo
1999AZhatch is offline  
Old 08-12-2018, 03:29 PM
  #2  
2x0
Honda-Tech Member
 
2x0's Avatar
 
Join Date: Oct 2011
Location: Rochester, MN
Posts: 1,567
Default Re: Low Fuel Trim under load in B16

Bad o2 sensor
2x0 is offline  
Old 08-12-2018, 05:22 PM
  #3  
Honda-Tech Member
Thread Starter
 
1999AZhatch's Avatar
 
Join Date: Jun 2018
Location: Tucson
Posts: 41
Default Re: Low Fuel Trim under load in B16

Always possible, though it did seem to be behaving on the live data on my scan tool.

its a cheap Bosch number, should I get a denso brand?
1999AZhatch is offline  
Old 08-12-2018, 07:37 PM
  #4  
Honda-Tech Member
 
Join Date: Jan 2013
Location: The South - Roll Tide !!!
Posts: 2,606
Default Re: Low Fuel Trim under load in B16

Yes, a quality O2 sensor is a good idea. Check for an exhaust leak. Also, what fuel pump do you have installed in the H/B ???
JRCivic1 is offline  
Old 08-13-2018, 10:30 AM
  #5  
Honda-Tech Member
Thread Starter
 
1999AZhatch's Avatar
 
Join Date: Jun 2018
Location: Tucson
Posts: 41
Default Re: Low Fuel Trim under load in B16

Iíve got a fuel pump I took out of my em1 parts car. Runs about 28-30psi at idle
1999AZhatch is offline  


Thread Tools
Search this Thread

Contact Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: