Misfire at idle only.
#1
Misfire at idle only.
I seem to have an intermittent misfire at idle. It only does it at low resting idle and not all of the time at that. My durametric indicates that it is on cylinder 4 which I think is the passenger side farthest rear cylinder. I'm going to swap around my spark plug and coil to check them. I am wondering if there is anything in my log to indicate that it could be an injector issue. This log is with my boost control valve unplugged in 3rd gear, so running on wastegates. The car rus great otherwise.
Last edited by Bernard IV; 05-30-2021 at 04:26 AM.
#3
I swapped the coil between cylinder 4 and 5 as well as installing new spark plugs. I'm still getting that same misfire. So my next possibilities are: wiring issue to the coil, compression issue, or a fuel issue.
#5
I'm going to try running one coil off with a spark plug in it to ground to see if it is sparking in time. I'll know it isn't electric then. I have a cyl compression test also so I'll try that too.
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#9
I put ratchet drive rod up to the injector and listened. It does sound like it is ticking properly. Next up I'm going to spin the motor with a compression tester connected to 4 and then 5 to see how that looks. Tomorrow.
#10
The compression in that cylinder is good, showing 125 psi with a quick turnover, throttle plates closed. We are down to a stuck lifter (sounds fine) and a bad injector. I'm betting it is the injector, not looking forward to getting in there.
#12
I think the driver side is actually worse. I got the air pump out, I think I'll be able to get at it. I'm just going to replace that one injector with a new one and hopefully that gets it. What was your injector doing?
#14
Changed the injector (not fun). This did not fix my problem unfortunately. I ran the car through the mountains and had a ton of fun though. Runs great when not sitting at idle for a while. I'll have to explore this further in the off season.
#15
the prior owner to my car had a weird misfire issue. it ended up being a cracked bracket that holds the cam sensor I believe. he had all the coils and plugs changed be fore they found it. I think it is a fairly common but weird issue on these