Intermittent misfire on sr20det - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

leanin sidewayz · 05-30-2015, 03:45 PM

So here's the deal my redtop has always had a jumpy idle that would only once in a blue mood stop stumbling, and smooth out then it was always right back to a 30-50rpm flux. Well that flux/jump is now even more apparent, and is more then likely a small mis.
So after 8 months of no issues other then a funky idle it dropped a cylinder after leaving work on my way home. I'd say a block or so away it kicked back in. I could get it into boost, no drivability issues. (I did note a small lack of power). I left it over night, and started it back up for work.
Got to work fine. Pushed into boost. Got off work started it up. Behold my new tractor/wrx. Back to 3 cylinders until right before I get home.

I narrowed it down to what I believe is cylinder #1 or #4. Closes one to the timing chain. I know this, because when it was misfiring outside of work that cylinder when the pack wire was pulled showed no change.

This is a pretty stock setup other the a walboro 255, FMIC, and an eBay bov the shop slapped on it.

I have noticed that this mis only happens if I warm it up, let it sit for 30 mins or so. Then when I go to fire it back up it's only on 3 cylinders. It stumbles through rpms like crazy even when it's hitting on all 4.

Here's what I have tried. Swapped packs around. Mis doesn't move. Put my ear to a screw driver to listen audibly that they are all clicking the same, and they are. Pulled the cylinders plug to find a small bit of carbon around the top ring. Not the actual node. Pulled one code off the ecu before resetting it, which btw I cannot get back. I got #11 CAS. Now I will note I have had the valve cover off to regime the CAS, because it was off like 4 teeth, and running like dump. It did help for awhile.
I have not got to a compression check due to it raining like mad men here in STL.

Oh, and for sits I dumped some FTP fuel injector cleaner in it before work today. It miss fired hard for a second (was already warm from me plunking around on it) then just stopped then back to rough. I could rev it with less stumble, but it still running like crap.

Would a CAS on it's way out cause all this confusion?

Any ideas would rock.

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05-30-2015, 03:45 PM	#1
leanin sidewayz Join Date: Dec 2014 Location: Saint louis Age: 27 Posts: 24 Trader Rating: (0) Feedback Score: 0 reviews	Intermittent misfire on sr20det So here's the deal my redtop has always had a jumpy idle that would only once in a blue mood stop stumbling, and smooth out then it was always right back to a 30-50rpm flux. Well that flux/jump is now even more apparent, and is more then likely a small mis. So after 8 months of no issues other then a funky idle it dropped a cylinder after leaving work on my way home. I'd say a block or so away it kicked back in. I could get it into boost, no drivability issues. (I did note a small lack of power). I left it over night, and started it back up for work. Got to work fine. Pushed into boost. Got off work started it up. Behold my new tractor/wrx. Back to 3 cylinders until right before I get home. I narrowed it down to what I believe is cylinder #1 or #4. Closes one to the timing chain. I know this, because when it was misfiring outside of work that cylinder when the pack wire was pulled showed no change. This is a pretty stock setup other the a walboro 255, FMIC, and an eBay bov the shop slapped on it. I have noticed that this mis only happens if I warm it up, let it sit for 30 mins or so. Then when I go to fire it back up it's only on 3 cylinders. It stumbles through rpms like crazy even when it's hitting on all 4. Here's what I have tried. Swapped packs around. Mis doesn't move. Put my ear to a screw driver to listen audibly that they are all clicking the same, and they are. Pulled the cylinders plug to find a small bit of carbon around the top ring. Not the actual node. Pulled one code off the ecu before resetting it, which btw I cannot get back. I got #11 CAS. Now I will note I have had the valve cover off to regime the CAS, because it was off like 4 teeth, and running like dump. It did help for awhile. I have not got to a compression check due to it raining like mad men here in STL. Oh, and for sits I dumped some FTP fuel injector cleaner in it before work today. It miss fired hard for a second (was already warm from me plunking around on it) then just stopped then back to rough. I could rev it with less stumble, but it still running like crap. Would a CAS on it's way out cause all this confusion? Any ideas would rock.