Notices
Engine & Drivetrain VQ Power and Delivery

Car dies on decel occasionally

Thread Tools
 
Search this Thread
 
Old 05-03-2016, 04:45 AM
  #1  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default Car dies on decel occasionally

So I have not had this issue before, but after having the battery unplugged for a while to reset BCM, now the car occasionally dies on decel. It does not happen all the time, and typically only happens after driving on the freeway for a while. Just normal driving, not hard at all. If I am parked and rev it, it won't die.

I could not find many people having this problem, and did not see any fixes. Wondering if there is any way to tune around this with uprev?

The car is uprev tuned and I bumped idle up to 875.

Also, the car does not idle at 1500(cold start) like it used to. As soon as I start it, it goes right to normal idle.

The only things I could assume would be issues are the exedy triple carbon clutch or throttle body. I do have an extra throttle body, but will try to unplug the ecu for a few hours today while at work to reset it.

Any suggestions on how to fix the problem would be helpful.

Thanks

Last edited by jdm-v35; 05-03-2016 at 04:47 AM.
Old 05-03-2016, 05:03 AM
  #2  
Highway Riding
New Member
iTrader: (6)
 
Highway Riding's Avatar
 
Join Date: Apr 2008
Location: Out on the Highway!
Posts: 5,543
Received 95 Likes on 80 Posts
Default

Believe or not check the Battery connections. Same thing happened to me. Was a loose connection. I couldnt tighten it when i found it and just threw in a Nail in between the leads and made it home no more stalling lmao !
Old 05-03-2016, 05:27 AM
  #3  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

hahaha Ill take a look. I had the same problem with ground connection to head. no spark so car would die, or not start. Everything else works fine, just on decel after highway driving it will die when stopping at the exit.
Old 05-03-2016, 06:46 AM
  #4  
turboed350z
Registered User
 
turboed350z's Avatar
 
Join Date: May 2014
Location: arizona
Posts: 2,892
Received 277 Likes on 215 Posts
Default

Are you dieing in gear or in neutral?

If youre dieing with the clutch in, check your rpm. If its dropping too low and the car cant catch itself, causing it to die, you probably have a leak in the vac line.
Old 05-03-2016, 07:18 AM
  #5  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

Thanks! ill take a look at that too. it will die when I put the clutch in. I will try to ride the gears out as low as possible till a stop, but even then it will sometimes die. parked and revving, it wont dip below 500 with uprev logging.

I will try to look for some leaks.
Old 05-03-2016, 07:35 AM
  #6  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

just went outside to unplug ecu for a few hrs. when i get home will look for leaks and check terminals.

any other suggestions?
Old 05-03-2016, 08:02 AM
  #7  
CK_32
New Member
iTrader: (1)
 
CK_32's Avatar
 
Join Date: Jan 2016
Location: California
Posts: 3,635
Received 366 Likes on 315 Posts
Default

Sounds like your getting too much or not enough air possibly. Check your filter, spark plugs and maybe injectors.


First place id start. My only car I had do this was my track s13 after it had a blown head gasket but I doubt that's your problem.
Old 05-03-2016, 08:23 AM
  #8  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

I think I will clean the filter. That could cause the issue. No overheating problems, but I will check the oil later too, to make sure there is no water. I hope it's not the headgasket.

It is a possibility because it was procharged, but I took it off and sold it a few months ago.
Old 05-03-2016, 09:06 AM
  #9  
travlee
Master
iTrader: (8)
 
travlee's Avatar
 
Join Date: Jul 2011
Location: Texas
Posts: 48,600
Received 9,045 Likes on 6,511 Posts
Default

did you get it tuned after the procharger removal?
Old 05-03-2016, 09:12 AM
  #10  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

yup! I have tuner version so I flashed it back to a stock map with slightly advanced timing, a little more fuel up top to get AFR's running nicely, and upped idle to 875.

It has been running fine after procharger removal for months now, until I disconnected the battery for a few hours a few weeks ago.

I'm thinking its either bad battery connection, dirty filter, or something to do with the ECU reset. I can't think of anything else. I will check all the above and I hope its not headgasket, though it would be a motivator to build it.
Old 05-04-2016, 05:22 AM
  #11  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

ecu reset did nothing... battery connections were fine.. filter is a little dirty but not bad.

I checked the oil and there is no coolant in it.. HOWEVER, I have the plenum side PCV hose removed(vented valve), and thought maybe the intake side pcv could be doing something.
I disconnected the driver side leaving the hose vented and plugged the intake side. It seems to be running better now. When I removed the intake side pcv hose it looks like the hose was wet with fuel inside. Not sure if I was imagining that, or if its really fuel since there was not much. Though im 75% sure it was a little gas because the hose was wet inside, but the TB and inside of the Ztube were completely dry with no signs of oil.

That would also cause it to run rich at idle drop if it was fuel mixing with the air. I am not sure what would cause that, though it leads me to believe rings could be a possibility? Can't think of any other ways fuel would get into the blowby.

No car dying this morning with pcv hose removed. I will see how it goes this afternoon as it always happens at a certain spot when I drive home in the afternoon when weather is warmer. I will also continue to monitor the drive side pcv hose.

Anyone have some insight on this?
Old 05-04-2016, 02:46 PM
  #12  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

hose looked fine today - no gas. I hooked it back up. cleaned filter, MAF, intake tube and TB. hopefully that helps. will find out tomorrow.
Old 05-04-2016, 05:49 PM
  #13  
rcdash
New Member
iTrader: (18)
 
rcdash's Avatar
 
Join Date: Jul 2005
Location: Chapel Hill, NC
Posts: 6,474
Received 65 Likes on 56 Posts
Default

Fuel vapor is supposed to come out of those vents (and be caught in a catch can or burnt again via the intake). It will not be enough to have it run rich.

Try a throttle body reset. And bump up idle. Jim Wolf also has a fix for rapid decel on his website (reversible equivalent of drilling a hole in TB).
Old 05-05-2016, 04:21 AM
  #14  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

Thanks for that info!! didn't know JWT had a fix for it. So far so good though! the cleaning has helped, but I will really find out on the way home when the weather is warmer. It always dies right before home on the freeway exit. If it does not happen today then I think it may be good to go.

Currently idle is bumped up to 875. Should I go higher with that clutch/flywheel setup? Not sure how much lighter it is than stock as it does not say in the clutch manual.
Old 05-05-2016, 06:54 PM
  #15  
jdm-v35
New Member
Thread Starter
iTrader: (7)
 
jdm-v35's Avatar
 
Join Date: Oct 2007
Location: CO
Posts: 659
Received 22 Likes on 19 Posts
Default

after all the cleaning it seems better today. but will continue to monitor
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
deportedflip
Engine & Drivetrain
6
04-22-2016 09:35 AM
yosip1115
Forced Induction
3
04-15-2016 11:26 AM
grr01gsr
Maintenance & Repair
3
04-12-2016 03:18 AM



Quick Reply: Car dies on decel occasionally



All times are GMT -8. The time now is 10:59 AM.