All Motor / Naturally Aspirated No power adders

rough idle after engine warms up

Thread Tools
 
Search this Thread
 
Old 09-30-2024, 12:30 PM
  #1  
Trial User
Thread Starter
 
brianlar757's Avatar
 
Join Date: Sep 2024
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default rough idle after engine warms up

Hello, I have a B20v with hondata that will start to run rough after it warms up. I came to a light one day and the engine died. Had to rev the engine to about 1500 for it to stay running. Also in the back yard for example when idling and it gets up to 180-190 degrees the engine shakes the af ratio runs lean and my volt gauge reads about 10v. there are no cels. I have replaced the alternator distributor iat sensor. I know this isn't a guarantee. It also happens after I run the car hard. After an autocross run or an oval time attack run. I have an event at VIR at the end of October and need some help please. Or maybe steer me in the right direction. Thank you, Brian,
Old 09-30-2024, 12:37 PM
  #2  
Honda-Tech Member
iTrader: (1)
 
spAdam's Avatar
 
Join Date: Jul 2002
Location: Boat on a Hill, CA
Posts: 9,286
Received 696 Likes on 537 Posts
Default Re: rough idle after engine warms up

Check your TPS in the data. See if it is reading above zero when idling. Reset if needed. Be aware if it's floating around with engine vibration, heat, or whatever - you may have a tired wire or imperfect connection somewhere. record a log from cold start all the way up to operating temp and see if TPS is returning to 0% every time you get off the pedal.

If the TPS is not going to 0% when you are completely off the throttle, the ecu doesn't know to switch over to idle control and the engine sputters and often dies while trying to breathe through a closed throttle without help from the IACV.

Quite possibly your issue is something else, but this reads like non-zero TPS problem.
Old 09-30-2024, 02:45 PM
  #3  
Trial User
Thread Starter
 
brianlar757's Avatar
 
Join Date: Sep 2024
Posts: 2
Likes: 0
Received 0 Likes on 0 Posts
Default Re: rough idle after engine warms up

Originally Posted by spAdam
Check your TPS in the data. See if it is reading above zero when idling. Reset if needed. Be aware if it's floating around with engine vibration, heat, or whatever - you may have a tired wire or imperfect connection somewhere. record a log from cold start all the way up to operating temp and see if TPS is returning to 0% every time you get off the pedal.

If the TPS is not going to 0% when you are completely off the throttle, the ecu doesn't know to switch over to idle control and the engine sputters and often dies while trying to breathe through a closed throttle without help from the IACV.

Quite possibly your issue is something else, but this reads like non-zero TPS problem.
I just ran the engine and it produced the same problem. TPS was at 0%. Engine warms up and fan cycles once then the afr goes into the 20s voltage drops below 11v and idle is below 800 rpm. Car was sitting still.
Old 09-30-2024, 08:19 PM
  #4  
Honda-Tech Member
 
JRCivic1's Avatar
 
Join Date: Jan 2013
Location: The South - Roll Tide !!!
Posts: 8,777
Received 895 Likes on 829 Posts
Default Re: rough idle after engine warms up

Low battery voltage reduces the fuel pump speed... thus, leaning out the engine. How high do you have to run the engine to get the voltage back up to 13.8 - 14.4 volts ?
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
WojtekG
Acura Integra
12
09-13-2018 07:15 AM
cdx280
Honda CRX / EF Civic (1988 - 1991)
1
09-01-2005 08:45 PM
toolpusher
Honda Prelude
1
03-15-2004 05:37 PM
cchev
Honda Civic / Del Sol (1992 - 2000)
2
01-23-2004 04:00 PM



Quick Reply: rough idle after engine warms up



All times are GMT -8. The time now is 01:18 AM.