Jrah2987

iTrader: (9)

Hello,

I'm having an issue where it feels like I'm losing a cylinder or 2 while driving the car for more than 20ish minutes. When it occurs, I have to keep the car alive with my right foot, otherwise it stalls. After it sits for a while and cools down, the car starts and runs like normal. Not sure how to narrow down the issue at this point. So far I've replaced the plugs and checked all fuses.

Mods that matter:
SpoolinUp COP ( ~500 miles)
FIC 1250s (~8000 miles)
Spark plugs (~100 miles)
AEM EMS v1

Any advice on how to proceed with troubleshooting would be much appreciated.

JD Customs USA

iTrader: (1)

Have you checked the connections for the COP on each side? If they are coming loose it would cause two cylinders to misfire.

IzzyRS

iTrader: (8)

I had similar issues due to a faulty Omni4 bar. Are you on MAF or SD?

Biggiesacks

If you have it, throw the stock ignition back in and see if the problem goes away.

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2006EvoIXer

iTrader: (1)

Need more info. When it runs on 2 cylinders, does it sound like a Subaru? Did this recently started happening where it ran fine after tune? Do you have an AFR gauge to see if you are running rich or lean?

Jrah2987

iTrader: (9)

Yes, they seem to be hanging in there.

I didn't even think about that. I'm on SD.

That was the first thing I thought of, but I must have pitched or sold the OEM one, unfortunately.

Doesn't really sound like a Subaru. Just sounds really weak, sputters, and eventually stalls. The idle drops as well. I run GSC S2 cams and an open down pipe, so it's usually pretty loud. The very first time it happened was when I picked it up from a body shop after it had been parked outside in a couple rain storms. Not sure if water could be affecting something with these symptoms. AFR looks perfect when it's running normal. Hard to tell when it isn't, because usually I'm just trying to keep it alive with my right foot so I can get home.

Jrah2987

iTrader: (9)

So, it just happened again, this time after only about 10 minutes of driving in 80 degree overcast. I think I can rule out the connectors to the COP, because as it was sputtering, I unplugged one, car died, started it back up, unplugged the other, car died again. I also took a look at my AFR while it was happening... it seemed to idle a bit rich, but then settled around normal.

I'm going to go ahead and buy another Omni 4 bar now, just to see if it's an easy fix.

2006EvoIXer

iTrader: (1)

If Omni is going bad, I think it runs lean. Running rich could be a boost leak somewhere. When was your last tune?

Jrah2987

iTrader: (9)

It's been 2 years, but it stays in the garage more than anything. Maybe been 4-5k miles since last tune. I've done a pull while the car has been running normal, and it seems perfectly fine.

Map sensor should be here in a couple days, so we'll see what happens after I swap it.

Jrah2987

iTrader: (9)

Installed the new Omni today, but unfortunately, it didn't help. Same symptoms as before. I've reached out to SpoolinUp for some troubleshooting advice, since that's next on my list.

Can anyone think of anything else I could test in the meantime?

JD Customs USA

iTrader: (1)

Have you tried swapping out your cam position sensor(s)? If you have a friend with an evo it wouldn't be a bad idea to try swapping out a few things to see if anything makes a difference. I've had to do that before.

2006EvoIXer

iTrader: (1)

Do you have a way to log your ECU parameters? Otherwise, do a boost leak test and check your AIT and all the wirings to make sure all have a solid contact.

Jrah2987

iTrader: (9)

None local. Not sure if the cam sensor has ever been replaced, so it may be a good idea even if it's not causing this issue.

I don't, currently. This is the first real running issue I've had with the car in 8 years of owning it, so I don't have much troubleshooting tools.

Matt from SpoolinUp gave me some ideas, so I will be getting the COP checked out and report back. Thanks again.

2006EvoIXer

iTrader: (1)

Have you ever replaced your throttle body seals before? Those leak over time.

kaj

iTrader: (60)

First: It's not a vacuum or boost leak, but it could be so many other things. I just sent a text to a friend who had the same problem for a couple of years. If I remember right, his VSS was going bad, so the ECU would start doing really weird things. Don't quote me on that yet, though. I'm waiting to hear back.
But the car cutting out can be soooo many things. I doubt it's a problem, but... how close is your O2 sensor to the end of the open downpipe?