Notices
Evo Engine / Turbo / Drivetrain Everything from engine management to the best clutch and flywheel.

Stock 2005 EVO 8 Rough Idle

 
Old Aug 10, 2017, 11:39 AM
  #1  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
Stock 2005 EVO 8 Rough Idle

I'm the new owner of a bone stock evo 8. I recently installed an ACT Flywheel, Clutch, and Pressure Plate on it. After it was back together and I took it for a spin around the block and it ran fine, a couple hours later I started it up and now it has a rough idle. I ran some basic diag tests on it and noticed high fuel trims (20%). I went over the car again and double/triple checked EVERYTHING to no avail. There shouldn't be any issues, but there is and I'm out of ideas. If anyone has any insight to my issue, I would greatly appreciate any direction toward the answer. Thank you in advance.
Braineater6 is offline  
Old Aug 10, 2017, 12:38 PM
  #2  
EvoM Super Moderator
iTrader: (3)
 
MinusPrevious's Avatar
 
Join Date: May 2008
Location: Billings MT
Posts: 6,027
Received 855 Likes on 816 Posts
First off, thanks for joining on the EvOM boards

Sorry to hear of the issue.

Im more suspension savy vs drivetrain, but not sure if the clutch replacement issue is tied to this rough idle unless its a vibration youre getting from the new clutch

When you say you checked the fuel trims, do you have an ECU log you can post up here so the guys can take a look at it? (we have a paperclip icon that enables you can upload varies file formats)
MinusPrevious is offline  
Old Aug 10, 2017, 12:54 PM
  #3  
Evolved Member
iTrader: (1)
 
letsgetthisdone's Avatar
 
Join Date: Oct 2013
Location: Las Vegas
Posts: 12,505
Received 750 Likes on 705 Posts
Make sure you don't have any vacuum leaks. Like the crankcase breather hose not attached to the intake. This will make the car run lean, and run high positive fuel trims if you're running a MAF.
letsgetthisdone is online now  
Old Aug 10, 2017, 01:09 PM
  #4  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
Thanks. Unfortunately no, it's a hand held diag tool. It goes into every gear nicely and grabs the flywheel well. I did the relearn procedure for the ECU and It's Idling well. Just got back from a test drive and it's idling rough again...
Braineater6 is offline  
Old Aug 10, 2017, 02:26 PM
  #5  
Newbie
 
Join Date: Aug 2017
Location: NM
Posts: 60
Likes: 0
Received 4 Likes on 4 Posts
Last time i changed my clutch i cracked the egr solenoid vacuum port. I didnt noticed much of a rough idle but it did throw a code. Might wanna check that because its really hidden behind the intake manifold
slocho is offline  
Old Aug 10, 2017, 02:33 PM
  #6  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
No vacuum leaks, throttle body is clean, throttle body seals are good, I cleaned the MAF, and all connections are tight and sealed. The crazy thing is after I pulled it into my garage, sat there with a ****ty idle checked the data stream (key on engine off) and noticed it went into open loop when I wasn't driving (stop sign, turns, etc...) so I decided to take it out again and record the data stream. When I stopped at the end of my driveway it was smooth as could be; Good trims, nice flat idle, and steady RPMs. Took it about a mile down the road and it's loping again with erratic fuel trims. I'll try to copy the vids from my phone.
Braineater6 is offline  
Old Aug 10, 2017, 02:35 PM
  #7  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
Originally Posted by slocho View Post
Last time i changed my clutch i cracked the egr solenoid vacuum port. I didnt noticed much of a rough idle but it did throw a code. Might wanna check that because its really hidden behind the intake manifold
the EGR solenoid is visually intact, the wire is connected and I have no codes so far.
Braineater6 is offline  
Old Aug 10, 2017, 02:37 PM
  #8  
Evolved Member
iTrader: (38)
 
gsrboi80's Avatar
 
Join Date: Aug 2005
Location: On a cliff
Posts: 7,811
Received 21 Likes on 21 Posts
Evo takes a bit to relearn idle after disconnecting the battery, though I've ever only noticed it with intake modifications on MAF cars usually.

Check for boost/vacuum leaks as noted above. Perform a proper boost leak test and make sure all the hose connections underneath the Intake Manifold are connected correctly. Which ACT flywheel did you put in the car? Shouldn't matter but I never ran anything really light (<12 lbs or so) in an Evo so don't know what effect it may have on drivability. Don't know where in NJ you are but there are a lot of us in the NE that can help you go back over it, or data log the car to get a better idea what's going on.
gsrboi80 is offline  
Old Aug 10, 2017, 02:45 PM
  #9  
Evolved Member
iTrader: (38)
 
gsrboi80's Avatar
 
Join Date: Aug 2005
Location: On a cliff
Posts: 7,811
Received 21 Likes on 21 Posts
Another thing is you stated that the TB was clean, did you clean it. If so that's likely the problem. Been posted on here quite a bit over the years that cleaning the back of the throttle plate causes issues as the TB plate has a sort of dry lubricant/sealant on it from the factory, also could have a damaged/bad IACS or TPS.

Certainly wouldn't be the first time someone work on one thing and something else went bad coincidentally
gsrboi80 is offline  
Old Aug 10, 2017, 04:06 PM
  #10  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
Originally Posted by gsrboi80 View Post
Another thing is you stated that the TB was clean, did you clean it. If so that's likely the problem. Been posted on here quite a bit over the years that cleaning the back of the throttle plate causes issues as the TB plate has a sort of dry lubricant/sealant on it from the factory, also could have a damaged/bad IACS or TPS.

Certainly wouldn't be the first time someone work on one thing and something else went bad coincidentally

I considered cleaning the Throttle Body as a possible culprit, and I know all about fixing one thing and another bites the dust, but the problem existed before I cleaned the TB, coincidentally the boost leak test is why I ended up cleaning it, and since the seals are known to go bad I replaced them as well. I also cleaned the pcv valve due to a slight hesitation to open. Every vacuum hose is firmly connected correctly (I label everything before I remove it and double check it with a diagram when I reassemble). I'm starting to think the MAF sensor may be jerking me around, I noticed it wasn't exactly clean after the Boost Leak Test. I followed all of the proper procedures to clean that as well. Thinking it might also be a potential culprit to my sloppy idle.
Braineater6 is offline  
The following users liked this post:
WRC-LVR (Aug 12, 2017)
Old Aug 10, 2017, 04:50 PM
  #11  
Newbie
Thread Starter
 
Join Date: Aug 2017
Location: nj
Posts: 6
Likes: 0
Received 1 Like on 1 Post
Alright, so the most recent thing I did was the pcv valve. When I tested it, it wasn't opening as easily as I would've liked so I figured at this point it can't hurt to clean this thing too. Started it, let it warm up, steady and smooth idle. Ok. Took it for a test drive, and it was well behaved during the ride and after I returned home and let it sit idling for 10-15 mins. I suppose it's fixed? I'm done with the damn thing for tonight. I'll post an update after a few more drive cycles. Thanks for all your help folks. It's appericiated. Hopefully I tracked the issue down. I'm still unsure if it's fixed or if the pcv was the bastard gremlin, either way I'll keep you posted. Thanks again.
Braineater6 is offline  
Old Aug 12, 2017, 12:39 AM
  #12  
Evolved Member
iTrader: (1)
 
WRC-LVR's Avatar
 
Join Date: May 2008
Location: Marietta GA
Posts: 875
Received 8 Likes on 8 Posts
Originally Posted by Braineater6 View Post
I considered cleaning the Throttle Body as a possible culprit, and I know all about fixing one thing and another bites the dust, but the problem existed before I cleaned the TB, coincidentally the boost leak test is why I ended up cleaning it, and since the seals are known to go bad I replaced them as well. I also cleaned the pcv valve due to a slight hesitation to open. Every vacuum hose is firmly connected correctly (I label everything before I remove it and double check it with a diagram when I reassemble). I'm starting to think the MAF sensor may be jerking me around, I noticed it wasn't exactly clean after the Boost Leak Test. I followed all of the proper procedures to clean that as well. Thinking it might also be a potential culprit to my sloppy idle.
When my MAF went bad, it showed up as random hesitating on steady throttle, minor hiccups under light acceleration. Idle was good though. Chased a lot of parts to fix ( coils, wires plugs EGR etc ) Putting a brand new MAF on immediately cured the issue. ( rock auto.com)

several threads on it but not clear that MAF responds to cleaning ( it did not on mine ) as it is a Karman vortex type.

Make sure the MAF is plugged in properly too, sometimes it looks like it is in but not really connected.

Last edited by WRC-LVR; Aug 12, 2017 at 07:42 PM.
WRC-LVR is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
shane_evo7
Evo Engine / Turbo / Drivetrain
2
Mar 7, 2019 05:49 PM
Siluck2
Evo Engine / Turbo / Drivetrain
11
Apr 11, 2016 06:06 PM
Graphic
Evo Engine / Turbo / Drivetrain
7
Jun 16, 2012 11:45 PM
whitedemon
Evo General
3
Jun 4, 2011 12:29 PM
hawkmoon
Lancer Troubleshooting
13
Jan 26, 2004 11:36 PM


Thread Tools
Search this Thread
Quick Reply: Stock 2005 EVO 8 Rough Idle


Contact Us - About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 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.