vbwstripes Posted August 31, 2017 Share Posted August 31, 2017 Hi all, I am having a pretty bad misfire on cyl# 2. Engine has 108,000 miles. Here is what I have done recently: Leakdown test 8-24-17 1 20% 2 17% 3 17% 4 15% New non OEM ignition coils (Last fall) Had the injectors cleaned and flow tested (Last fall) Replaced intake manifold gaskets and TGV delete (Last fall) During the winter I had a misfire on cyl#4, so I switched plugs, then ignition coils, and finally injectors from 2 to 4. I switched items when I detected a misfire, but I never got a misfire after I switched injectors until just recently. The engine was much jerkier than before, and I detected 30 knocks in cyl#2 just at idle with the AC on. So, I'm leaning towards faulty injector. I am going to switch them again and see what happens. If you have any other insight please let me know! Thanks, and I appreciate all of the help I've had from this forum from just lurking. Link to comment Share on other sites More sharing options...
Max Capacity Posted August 31, 2017 Share Posted August 31, 2017 I think 3 of those numbers are out of spec ? Did you do a compression test ? do you have the service manual, http://people.csail.mit.edu/ilh/vacation/ 305,600miles 5/2012 ej257 short block, 8/2011 installed VF52 turbo, @20.8psi, 280whp, 300ftlbs. (SOLD). CHECK your oil, these cars use it. Engine Build - Click Here Link to comment Share on other sites More sharing options...
Moderators BarManBean Posted August 31, 2017 Moderators Share Posted August 31, 2017 Those leakdown numbers seem pretty poor, but also pretty consistent. Unsure what that means really. "Bullet-proof" your OEM TMIC! <<Buy your kit here>> Not currently in stock Link to comment Share on other sites More sharing options...
Jaybird2013 Posted September 1, 2017 Share Posted September 1, 2017 Barring the leakdown results, I would strongly consider new OEM coil packs. I had terrible luck with Non OEM replacements just to save a few bucks. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 1, 2017 Share Posted September 1, 2017 Was the leakdown test done with a warm or cold engine? Probably time to check valve clearance too. Link to comment Share on other sites More sharing options...
vbwstripes Posted September 4, 2017 Author Share Posted September 4, 2017 Sorry for the late reply. The test was done warm. I did not do a compression test. I did not hear any leaking from the intake or exhaust when I did the leakdown test. I have one OEM ignition coil I'm going to throw on cyl#2 and see what happens. Link to comment Share on other sites More sharing options...
vbwstripes Posted September 26, 2017 Author Share Posted September 26, 2017 I ended up replacing all of the aftermarket coils with OEM after replacing the misfiring coil with an oem one. I haven't had a check engine light come back yet. I still have some stumble at idle and around 2500. I'm going to change the vacuum source for the fpr from the #4 intake runner to the bov, but I can't find a good tee so I'm going to get a turkeylord tee. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 26, 2017 Share Posted September 26, 2017 Look into the btssm app. Get it. Once up and running, monitor the misfire per cylinder and note when/if these occur. Link to comment Share on other sites More sharing options...
vbwstripes Posted September 27, 2017 Author Share Posted September 27, 2017 I have a tactrix cable and previous to changing to the OEM coils I was getting 10s of misfires at idle with the A/C on. After changing the coils I'm not really seeing any while driving besides the odd count at idle. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted September 27, 2017 Share Posted September 27, 2017 ok. How many counts do you see at idle now? Do you see them occuring in the same cylinder each time? Or do you see like a count of 1 or 2 in random cylinders at idle? Link to comment Share on other sites More sharing options...
vbwstripes Posted October 5, 2017 Author Share Posted October 5, 2017 I see 0-2 counts in cylinders 1-3 and up to 30 in cylinder 4 at warm up. After warm up 0 misfires in all cylinders. This is odd to me. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted October 5, 2017 Share Posted October 5, 2017 So #2 is now free of misfires then. That's good. So I hope it is not what I am thinking it is (broken ringland). With a slightly cracked ringland, compression is lower when the engine is cold, which would easily throw misfires. But when the engine warms up, the rings expand a bit, thereby 'closing the cracks' and increasing compression back. And that will stop throwing misfires. You have done a warm leakdown test already. Although pretty high, your numbers were fairly consistent across all cylinders. So this *may* rule out valve clearance issues. Note the emphasis on 'may'! So at this point (assuming you have indeed checked spark plug/injector/coil pack), I would still check the valve clearance and probably check the cylinder walls for scoring with a borescope. Finally, fwiw, I suffered from the same issue on cylinder 2. I also did a (cold) leakdown test and results came out great (5%!!). Spark plug/injector/coil pack were fine. So I began to convince myself that my rings were shot. Yet, I decided one morning to check the valve clearance. And one exhaust valve had zero clearance! After the fix, all good. Link to comment Share on other sites More sharing options...
vbwstripes Posted January 8, 2018 Author Share Posted January 8, 2018 One of my exhaust valves was at zero clearance in cyl #2. I ended up adjusting the valves to within spec and then threw a CEL almost immediately after driving for awhile. P0172 too rich. Replaced the MAF and everything seems ok for now. Link to comment Share on other sites More sharing options...
xt2005bonbon Posted January 8, 2018 Share Posted January 8, 2018 Good job! Then you should be good to go for many miles now. Keep an eye on the misfire counts still for a while. But I bet you will be fine. Link to comment Share on other sites More sharing options...
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