Need Help Diagnosing P0301 Cyl 1 Misfire

[icudruln]

So, a long story short: I was driving the car normally, and it felt like it was missing at idle. I drove the car normally to another stop light, and the car idled really low and quiet. Finally, a CEL pops up (p0301 Cylinder 1 misfire).

Obviously, I'll want to check the spark plugs and coilpacks, but I wanted to know if there's anything in Rom Raider that could help pinpoint my problem? Does Rom Raider show anything in regards to spark or coil packs? Anything else to look for or take a look at?

It's been a long month with cars breaking and no laptop to get on here (I'm typing on my iPhone), but hopefully I'll be back on here more. Help a brother out!

 

[HolyCrapItsFast]

I believe if you log "Roughness Cyl 1,2,3,4" you could monitor misfires on each cylinder.

It won't necessarily tell you whether it is a coil pack or an injector but it will clue you into what cylinder is seeing the most misfires.

I hate to say it but also have a compression test done. Ring landings can cause misfires also but usually the misfires are very noticeable at that point.

If you are experiencing misfire code but are not experiencing any noticeable roughness, then it could just be phantom events caused by light weight flywheels and pulleys or large injectors or cams.

 

[icudruln]

Thanks for the tips Holy. I got my laptop back, download Romraider, and will log it in the morning. I'll be sure to post it here, since I'm not the most knowledgeable when it comes to reading them; I'm sure it'll stick out, but I'll definitely post it.

I plan on getting the compression checked just to be safe. I'm on the same setup I've been on since May of last year (9k miles), and I'd think the only big change (PE 850cc injectors) would've caused the same code to happen before this.


Things I'll be checking (in order):
Clean K&N Filter
Datalog Cylinder Roughness and check fuel and ignition tables and trims
Pre Throttle Body leaks - let it sit at idle and spray brake clean in intake side piping
Check Cylinder One Spark Plug for Fouling
Check Resistance of Cylinder One Coil Pack
Swap Cylinder One Spark Plug with TBD (after Datalog) spark plug
Swap Cylinder One Coil Pack with TBD (after Datalog) Coil Pack
Possibly replace Spark Plug or Coil Pack
Compression Test

 

[BAD STI]

Do you have a compression tester yet? I also had some missfires and am replacing the plugs and doing a compression test just for added measure.

I'm picking up one of these this week:

http://www.sears.com/shc/s/p_10153_...21x00003a&ci_src=14110944&ci_sku=00947089000P

 

[icudruln]

Do you have a compression tester yet? I also had some missfires and am replacing the plugs and doing a compression test just for added measure.

I'm picking up one of these this week:

http://www.sears.com/shc/s/p_10153_...21x00003a&ci_src=14110944&ci_sku=00947089000P

I'm really tempted to go and buy one, but I'll borrow my buddy's gauge for now; two broken cars and being engaged don't sit well for buying car parts or tools anymore . Last I remember, the passenger side front plug was the easiest to get to (Cylinder One), so for this purpose, I guess I'm "happy" that the miss is there.

 

[icudruln]

+1
Compression tests are a good thing to perform as a measure of your engine's health.

+1

As much as I hate to say it, I feel like I don't take care of my car as well as I should.

- Fail to do oil analysis'
- Don't check spark plugs as often as I feel I should (every 10k miles)
- Dirty ass air filter
- Ideally send out injectors once a year/every 15k miles to be cleaned and flow tested
- Compression test every time I should check the plugs
- Misc scratches and dents that could be fixed/pulled
- Interior floor is annoyingly dirty
- Broken wideband

I want to cry after reading that list to myself.

 

[HolyCrapItsFast]

Dude this sounds EXACTLY like my car... Only add on top of that a broken coilover, never checks the coolant level or brakes, shredded tires from drifting and an idiot behind the wheel. :tup:

+1

As much as I hate to say it, I feel like I don't take care of my car as well as I should.

- Fail to do oil analysis'
- Don't check spark plugs as often as I feel I should (every 10k miles)
- Dirty ass air filter
- Ideally send out injectors once a year/every 15k miles to be cleaned and flow tested
- Compression test every time I should check the plugs
- Misc scratches and dents that could be fixed/pulled
- Interior floor is annoyingly dirty
- Broken wideband

I want to cry after reading that list to myself.

 

[icudruln]

Do you have a light flywheel or light crankj pully by chance???

Nah, stock pulley system and flywheel as of now. I have an ACT Streetlite flywheel sitting on my floor, waiting to be installed with the ACT-XTSS.

 

[icudruln]

Dude this sounds EXACTLY like my car... Only add on top of that a broken coilover, never checks the coolant level or brakes, shredded tires from drifting and an idiot behind the wheel. :tup:

:lol: Maybe I shouldn't feel so bad after all.

 

[icudruln]

Clean the MAF sensor and check your spark plug gaps. Then let me know. Ive eaten 5 sti motors so far and Im pretty much an expert of stupid subie misfires.

Will do. I'll clean the MAF with a light spray of brake clean, as well as log MAF Voltage. I'm getting going on this whole thing as I type. Cleaning off the air filter, will be logging once its cleaned up. I don't think I'll have time to pull the plugs today (I work from 1-9MST), but we'll see.

 

[icudruln]

Filthy and dried up K&N Filter:

 

[icudruln]

Just curious as to what should I expect for MAF Voltage readings, as well as cylinder roughness readings? I'll be posting a log within the hour.

 

[icudruln]

So I'm having issues with Rom Raider and getting the Definition Files updated and correct. I downloaded the new definition files, unzipped it, added it via ECU Manager, and it still says the same thing. Is this why the tactrix cable and Romraider won't read properly?

This is what I'm getting and doing:

1. Rom Raider - ECU Definitions not configured. Go online to download latest definitions? (Yes or No)
I click yes.

2. Dowload ECU Definitions that are given at the bottom of the Rom Raider thread.

3. Unzip file that is dowloaded. I extract all files.

4. I run Rom Raider ECU Manager, as stated by Rom Raider's thread.

5. It opens a Java box, which allows you to add, delete, save ECU definitions.

6. Nothing is in this box, which is what I want. I need to add the ECU definitions I just extracted and move them here.

7. I add the unzipped definitions, and click save.

8. I exit Rom Raider ECU Manager, and go to ECU Logger. I get the same "Logger Definition Not Configured" message, and it asks me to repeat the whole process all over. It says that Logger Definitions must be configured before it will read from the ECU.

What am I doing wrong?! Ugh this sucks.

 

[HolyCrapItsFast]

99% of the time, communication issues with RR are because of the definition files. There are separate definition files for logging as well. I'm not an expert so you might want to visit the RomRaider forums for some assistance in that respect.

 

[icudruln]

99% of the time, communication issues with RR are because of the definition files. There are separate definition files for logging as well. I'm not an expert so you might want to visit the RomRaider forums for some assistance in that respect.

Will do, Holy. I just registered and made a post saying the same as above. Hopefully someone can clarify what's going on.

 

[icudruln]

So guys, I still haven't got Rom Raider to connect properly. The good news being that I found a pin sized hole in the fuel sending line off the FPR :-o. I kinda freaked when I found it. I took advantage of the slow time at work to have a buddy run to the parts store and pick up some 5/16" fuel line. I replaced it, after trying to properly cramp my hands inbetween the drivers side intake manifold runners.

The car runs like normal at idle, and at low (>2000 RPM) driving. I cleared the CEL, and it hasn't come back in the 20 miles I've put on the car since. At the same time, it sounds like a slight pop (still thinking a small misfire) in the exhaust every now and then; maybe one out of every 5 shifts. The popping wasn't consistent in any gear, it happened with light load (boost) and no load (vacuum). It was most prominent in low RPM shifts though...below 3000.

I still haven't gone WOT, in case its an injector, as to not run the car lean. I am still dead set on continuing the process of checking the plugs and compression...I don't do half assed work, especially on my own car.

First and foremost, check the plugs. If their 1 step colders or Iridium plugs do not check the gap or you will hurt the electrode. Now, if youve been running rich as hell for an extended period, the gapo has proabally seperated and could be causing the misfires as well as foul a plug and cause the same issue. I usually change plugs every 4-6 months due to this issue so if your plugs are kinda old, get new ones and let me know if the misfires go away.

Definitely will do Rek. They're NGK Iridium One Step Colder Plugs. Thanks for the heads up on not checking the gap; I could see me doing this, so big thanks :lol:. I'm at 67,000 miles I think. I want to say I installed the plugs in the mid 40k range...around 45,000 miles. Honestly, I'm not 100% sure when they went in. I bought the car at 32,000, and I clearly remember them being one of the first things I ordered, since I was still getting parts from Rally Sport Direct :roll:.

Regardless, I'll definitely check the condition of the plugs. If the car doesn't throw a CEL in the next few days, I'll wait until the daily is running, and wait to check the plugs when I do a compression test.

Any other tips are GLADLY welcome.