Yet another Idle Issue...
Jun 24, 2020, 05:46 PM
#1
Newbie
Thread Starter
Join Date: Jun 2020
Location: Idaho
Posts: 2
Likes: 0
Received 0 Likes
on
0 Posts
Yet another Idle Issue...
I know there's a billion "rough idle" posts out there, however the issue I'm encountering seems to be more unique.
This began all of the sudden, pretty randomly. Upon initial start it will almost instantly die. It'll crank and then after a second or two it will off itself. Give it a bit of gas, and it'll sound real slow and lopey and range from 0-500 rpm until it eventually offs itself randomly might do that for up to 10 seconds or 5 seconds. I took it to my tuner as I thought that was the issue, however he's saying it has to be mechanical. He unplugged the MAF and it idled and didn't just die right away. No codes being thrown or anything to give us any clues unfortunately. We replaced the MAF and it still had the same issue. My tuner suggested to check for vacuum leak. I replaced all of the vacuum hoses with new lines and made sure everything was clamped on tight, and it still has the bad idle. Very frustrating as coming to complete stops in traffic required you to keep pressing the throttle to keep it from dying. When you're actually driving, it drives perfect! Power feels amazing and nothing out of the ordinary. One very interesting characteristic I found a few times, at idle I revved to 3k and let it drop and randomly idled perfect. I left it on and it kept the idle for 10 minutes, I thought the issue was "magically" resolved! I started it again 30 minutes after I shut it off and to check if it was permanently resolved, and sure enough it was back to its old ways... tried doing it again since and hasn't worked yet.
I am absolutely stumped here, so I'm checking with some other evo owners here to see if any of you have ever seen/heard of anything like this.
Also to be clear, none of the hoses are popped off and dangling. I have heard the Brake Booster might be the culprit for a vacuum leak as well?
Really just don't want to **** money away chasing this problem buying parts that aren't necessary. Looking for advice!
My evo x is pretty modified, I'll include as much as I can think of, but the list is pretty extensive.
Built Block+New Valvetrain 1500 miles on motor. Most of these components are brand new, so I doubt they're faulty.
MAPerformance Tubular Manifold + 02Dump DP
MAPerformance Breather Box Catch can
ETS Race Test Pipe
FullRace Catback Exhaust
GSC S2 Cam
Fuel Labs FPR
ETS Intercooler piping
ETS Intercooler
GTX 3576R Gen 2
Grimspeed 3port BCS
525 Walbro FP
Inline Fuel Filter
FIC 1100 injectors
New Fuel Filter
New Spark Plugs
New Fuel pump relay
New MAF sensor
Plz help.
This began all of the sudden, pretty randomly. Upon initial start it will almost instantly die. It'll crank and then after a second or two it will off itself. Give it a bit of gas, and it'll sound real slow and lopey and range from 0-500 rpm until it eventually offs itself randomly might do that for up to 10 seconds or 5 seconds. I took it to my tuner as I thought that was the issue, however he's saying it has to be mechanical. He unplugged the MAF and it idled and didn't just die right away. No codes being thrown or anything to give us any clues unfortunately. We replaced the MAF and it still had the same issue. My tuner suggested to check for vacuum leak. I replaced all of the vacuum hoses with new lines and made sure everything was clamped on tight, and it still has the bad idle. Very frustrating as coming to complete stops in traffic required you to keep pressing the throttle to keep it from dying. When you're actually driving, it drives perfect! Power feels amazing and nothing out of the ordinary. One very interesting characteristic I found a few times, at idle I revved to 3k and let it drop and randomly idled perfect. I left it on and it kept the idle for 10 minutes, I thought the issue was "magically" resolved! I started it again 30 minutes after I shut it off and to check if it was permanently resolved, and sure enough it was back to its old ways... tried doing it again since and hasn't worked yet.
I am absolutely stumped here, so I'm checking with some other evo owners here to see if any of you have ever seen/heard of anything like this.
Also to be clear, none of the hoses are popped off and dangling. I have heard the Brake Booster might be the culprit for a vacuum leak as well?
Really just don't want to **** money away chasing this problem buying parts that aren't necessary. Looking for advice!
My evo x is pretty modified, I'll include as much as I can think of, but the list is pretty extensive.
Built Block+New Valvetrain 1500 miles on motor. Most of these components are brand new, so I doubt they're faulty.
MAPerformance Tubular Manifold + 02Dump DP
MAPerformance Breather Box Catch can
ETS Race Test Pipe
FullRace Catback Exhaust
GSC S2 Cam
Fuel Labs FPR
ETS Intercooler piping
ETS Intercooler
GTX 3576R Gen 2
Grimspeed 3port BCS
525 Walbro FP
Inline Fuel Filter
FIC 1100 injectors
New Fuel Filter
New Spark Plugs
New Fuel pump relay
New MAF sensor
Plz help.
Jun 26, 2020, 12:39 PM
#4
Thanks for sharing. On the 8/9 cars, cleaning the TB plate causes issues since there is a coating that creates an air tight seal lol. I also had similar idle issues exactly as you described, but in my case it was a bad IAC. If I am not mistaken, the X does not use those anymore? (which is great because they are known to go out pretty often)
Thread
Thread Starter
Forum
Replies
Last Post
phishy
Evo X Engine Management / Tuning Forums
6
Dec 20, 2011 12:46 PM
