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Discussion Starter · #1 · (Edited)
stalling at idle (fixed) - Misfiring on Boost

My Evo 8 started to misfire as the boost comes on around 3k RPM in any gear, recently had a service done inc the plugs so swapped the plugs for another set still had the same issue.

Thought was one of the coil leads as it only effect on cylinder then after coming of a dual carriageway as the RPM's dropped it stalled :eek:

it struggled to start unless i pumped the accelerator, once started it runs as long as i keep a little pressure on the accelerator.

WTF is going on :cry:

 

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My Evo 8 started to misfire as the boost comes on around 3k RPM in any gear, recently had a service done inc the plugs so swapped the plugs for another set still had the same issue.

Thought was one of the coil leads as it only effect on cylinder then after coming of a dual carriageway as the RPM's dropped it stalled :eek:

it struggled to start unless i pumped the accelerator, once started it runs as long as i keep a little pressure on the accelerator.

WTF is going on :cry:

Vaccum leak?

Sent from my iPhone using Tapatalk
 

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Discussion Starter · #4 ·
Hi guys thanks for the replies.

It that just a case of tracing the pipe work from the intake, through the intercooler to the turbo and into the inlet manifold?

It's an Evo 9 BoV

Thanks
 

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My 6 is doing this sporadically as well and that's got a cone filter and a venting BOV. Was hoping returning it to stock would help cure the issue. Will be interested to see what you find. Yesterday mine sat happy idling for an hour then it started hunting a bit all on its own. When I went to drive it back into the garage it started stalling every time I took my foot off the throttle. Weird...!
 

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Sorry to sound think do you mean air getting in or air escaping?

And where would i start to look :confused:
Air getting in, to cause idle issues. Take the DV off and make sure it is sealing when closed, no bits of crap holding it open a fraction

As for leaks, you really need to pressure test the intake, search on here should show you how, but you will need a decent compressor with the pressure turned right down

Stu
 

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Hi,

I'd try to change the battery in the first place. I know it sounds silly, but if the battery is dying, the cars start to do really weird things. It happened to me (more or less same symptoms as you are describing). I even checked the battery status and all seemed ok (current, voltage drop and charge), but it wasn't.

So, I would start swapping the battery with another one (try a proper battery! 60Ah recommended) before going any deeper.

Hope it helps,

Good luck,
 

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try cleaning out the idle air control valve and inside the chamber as much as you can with brake cleaner and clean cloth

i had a similar issue with my 6 where sat at idle once warm revs would drop to say 500 then pickup in a similar fashion to what you're experiencing
http://www.lancerregister.com/showthread.php?t=529960

post 15 in the above thread

5 months on the issue has not returned :)
 

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What is the battery reset procedure? :confused:

Cheers!
Disconnect battery for 20 secs or so, reconnect, then let car tick over for 10 mins with everything electrical off, then continue for another 10 mins on with a lot of electrical stuff on

Just continuing to drive the car normally will over time sort things out too, but this process helps with the car idle if the battery has been off for any reason. Engine cutting out when revs drop to idle is 1 of the issues some people see after the battery has been disconnected, this process helps

Stu
 

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Discussion Starter · #15 ·
So, I would start swapping the battery with another one (try a proper battery! 60Ah recommended) before going any deeper.
thanks for the suggestion, I really hope its not the battery as i'm running a yellow top ultima and its only been in use a year and a half :eek:

I am leaning more towards something air related only because this is a secondary issue that cropped up, i was getting the misfire as the boost came on at 3k first and before this it would idle absolutely fine.

Once its started i only need to touch the accelerator pedal lightly to get it to continue running, its only when i completely take my foot off it dies :cry:
 

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Discussion Starter · #19 ·
Quick up date.

Had a mate help me work on this issues as i was at a loss, we adjusted the idle control screw a fraction to get the car to start, stay running and idle which was half the battle won.

So now we have one problem to remedy, misfiring on boost only.

We checked for boost and vac leaks using the trusted method of using break cleaner being sprayed on all the various pipes to see if it picked up at all but all pipes checked out fine.

As the plugs was changed less than 1k ago i know they are fine and tripple checked them for fouling and sooting but they are still spot on. Next thing to check is the coil packs so with the option of £260 for new oem replacements we opted to build a COP kit



Relatively straight swap but on the first run same thing again :cry: literally as the boost starts to build it misfires and stutters but does still accelerate.

so with my limited understanding of how the engine works it must be something to do with the Air/Fuel mixture, thinking possibly fuel delivery issues either pump or injectors :confused:
 

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Discussion Starter · #20 ·
Well i finally got mine sorted and its back to happy motoring :)

Turns out it was a combination of two things, firstly the spark plugs that were put in during my service (NGK Iridium BPR8EIX) are slightly better suited for a higher BHP(500-600BHP) than what i am running (360BHP) which meant effectively as the boost was coming in it was blowing the spark out so replaced them with NGK IGR7A-G 3106
secondly the COP kit i had made wasn't connecting properly and was arking due to the poor connection and also needed proper earthing.

Hope that helps others get to the bottom of there issue.
 
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