Shifting Tactics - Page 2 - Fuelly Forums

Android Users - Coming Soon! - Migrating from aCar 4.8 to 5.0

Reply
 
Thread Tools Display Modes
 
Old 11-17-2005, 06:12 AM   #11
Registered Member
 
Join Date: Sep 2005
Posts: 144
Country: United States
Yeah but as you slow down to

Yeah but as you slow down to a stop from a coast, do you notice anything happenning to the rpm right before the stop?
__________________

__________________
Scouring the country for an excellent condition Civic VX
Flatland2D is offline   Reply With Quote
Old 11-17-2005, 06:21 AM   #12
Registered Member
 
Join Date: Sep 2005
Posts: 144
Country: United States
Forogt to add this in my

Forgot to add this in my other post. I've also noticed it's hard to drive at certain speeds like ~35mph because as soon as I step on the gas it accelerates and doesn't just hold the speed. If I let off I'm coasting and slow down. It's a real fine line and can sometimes be really annoying speeding up and slowing down. I originially thought there was some play in the transmission because it's like the power kicks in all of a sudden. Makes the ride kind of jerky.

Now after thinking about the fuel injectors cutting off, I wonder if that's why it's so hard to hold a speed at a low rpm. Instantansous power keeps kicking on and off and makes it real hard to hold a constant speed.
__________________

__________________
Scouring the country for an excellent condition Civic VX
Flatland2D is offline   Reply With Quote
Old 11-17-2005, 06:54 AM   #13
Moderator
 
GasSavers_DaX's Avatar
 
Join Date: Oct 2005
Posts: 1,209
Country: United States
Re: Is there any reason why

Quote:
Originally Posted by Flatland2D
Is there any reason why automatics don't do this also? I was thinking they worked the same way. I've noticed in my wife's Civic (automatic) that there's a little blip in the rpm's around 1000 when coasting and coming to a stop.
From what I gather, that blip is the transmission shifting back into first gear from second. I'm sure the automatic hondas do have fuel shutoff on hard decel [it's hard to imagine they would not implement this just because the car is auto], but the auto transmission by nature tries to keep as low an RPM as possible at low to no throttle input, thus defeating [eventually] the fuel shutoff.

I'm looking at my OBD training manals for Hondas, and for MPFI <b>and</b> DPFI systems, it says "if the ECM receives a closed throttle input (under 0.5V), the engine speed is above 1100 RPM, and the engine is warmed, the fuel injectors will be shut off." There is no distinguishing between auto and manual.
GasSavers_DaX is offline   Reply With Quote
Old 11-17-2005, 07:06 AM   #14
Moderator
 
GasSavers_DaX's Avatar
 
Join Date: Oct 2005
Posts: 1,209
Country: United States
Re: Forogt to add this in my

Quote:
Originally Posted by Flatland2D
Forgot to add this in my other post. I've also noticed it's hard to drive at certain speeds like ~35mph because as soon as I step on the gas it accelerates and doesn't just hold the speed. If I let off I'm coasting and slow down. It's a real fine line and can sometimes be really annoying speeding up and slowing down. I originially thought there was some play in the transmission because it's like the power kicks in all of a sudden. Makes the ride kind of jerky.

Now after thinking about the fuel injectors cutting off, I wonder if that's why it's so hard to hold a speed at a low rpm. Instantansous power keeps kicking on and off and makes it real hard to hold a constant speed.
If you're talking about this happening in an automatic, it's probably because you are teetering on the shift speed of one of the clutches inside your transmission. If it's a 5-speed [I had this problem on one of my Civics], I'd look into either a vacuum leak or a dead spot in the TPS as the cause for the bucking.
GasSavers_DaX is offline   Reply With Quote
Old 11-17-2005, 10:33 AM   #15
Registered Member
 
Join Date: Sep 2005
Posts: 144
Country: United States
This is in a manual

This is in a manual transmission. I'm guessing it could be a dead spot in the TPS. I do have a small vacuum leak, but I don't think that would cause the problem in the way it is effecting my car. Thanks for the info about that.
__________________
Scouring the country for an excellent condition Civic VX
Flatland2D is offline   Reply With Quote
Old 11-17-2005, 11:05 AM   #16
Driving on E
 
Matt Timion's Avatar
 
Join Date: Sep 2005
Posts: 3,110
Country: United States
Re: This is in a manual

Quote:
Originally Posted by Flatland2D
This is in a manual transmission. I'm guessing it could be a dead spot in the TPS. I do have a small vacuum leak, but I don't think that would cause the problem in the way it is effecting my car. Thanks for the info about that.
If you want I can get a few TPS sensors the next time I'm at the junkyard and send one to you.
Matt Timion is offline   Reply With Quote
Old 11-17-2005, 11:30 AM   #17
Moderator
 
GasSavers_DaX's Avatar
 
Join Date: Oct 2005
Posts: 1,209
Country: United States
Re: This is in a manual

Quote:
Originally Posted by Matt Timion
If you want I can get a few TPS sensors the next time I'm at the junkyard and send one to you.
You should be snatching those up anyhow...pretty hard to come by these days, and dealerships won't sell them by themselves. You know how to get them off the throttle body, right? My brother dropped and broke one of mine and I about cried.

My FITV got messed up and was causing a vacuum leak at one point and my car bucked horribly until I fixed it.


Oh yeah, if any of you honda heads out there want a copy of these OBD training manuals I have, they are VERY informative for the PGMFI and OBD systems on honda cars up to but not including K-series stuff. The zip file is 8MB...I don't have an FTP or anything but I can email it.
GasSavers_DaX is offline   Reply With Quote
Old 11-17-2005, 12:42 PM   #18
Driving on E
 
Matt Timion's Avatar
 
Join Date: Sep 2005
Posts: 3,110
Country: United States
TPS Report...

I think I'll go get a bunch of TPS sensors at the junkyard. I'll test them with a multimeter and sell them on ebay.

oh yeah...

400th post for me!!
Matt Timion is offline   Reply With Quote
Old 11-25-2005, 03:07 AM   #19
Registered Member
 
Compaq888's Avatar
 
Join Date: Oct 2005
Posts: 1,460
Country: United States
Here is how my auto does it.

Here is how my auto does it. When I'm at speed let's say 30mph. If I want to slow down or just coast I just release the gas and the rpms go to 1000rpm or lower and the car keeps rolling and only loses a little bit of speed.

I usually coast 1-3 blocks If I see a stale green light or yellow or red. If nobody is around I coast as much as 4-5 blocks to the light.
__________________

Compaq888 is offline   Reply With Quote
Old 11-25-2005, 06:45 AM   #20
FE nut
 
diamondlarry's Avatar
 
Join Date: Sep 2005
Posts: 1,020
Country: United States
My 1992 Pontiac Gran Prix

My 1992 Pontiac Gran Prix acts the same way. It seems like it will coast forever by just taking my foot off the pedal.
__________________

__________________
Horsepower is how hard you hit the wall, torque is how much of the wall you take with you.

2007 Prius,



Team Slow Burn
diamondlarry is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Need to break out drivetrains Carphunter Fuelly Web Support and Community News 6 12-21-2016 06:05 AM
Partial Fuel-up Calculations Improvements ryogajyc Fuelly Web Support and Community News 16 04-17-2012 09:25 AM
Why fill my tank? acidtonic Fuelly Web Support and Community News 11 12-27-2010 07:27 AM
Basic Stats darkangel7 Fuelly Web Support and Community News 2 11-21-2010 05:29 PM
This is getting rediculous, LOL Compaq888 General Fuel Topics 4 11-19-2005 08:15 PM

Powered by vBadvanced CMPS v3.2.3


All times are GMT -8. The time now is 05:39 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.