Car shaking just at idle
08-09-2015, 11:00 AM
#21
Thread Starter
Have you recently done any work that may have compromised the vacuum system or MAP? Does it miss at high/med/low load? My car MY05 started doing the same thing 3 days ago with no CEL. At first the engine was running perfect, then I removed the air box and intake tube to do some mock up of a cold air intake. I re assembled the stock intake and stock air box after wiping some things down and inspecting the intake for oil (the only bolt on my whole power train is a catch can). Now i have the same misfire as you. Ive got a late MY05 that already has the MAP holder. My first though was I may have yanked the wire for the MAP and damaged it but it still reads 14.7 PSI at key on engine off and around 5 PSI at idle when its missing. My OBD reader is super slow and wont catch a micro miss of the MAP so it could be the MAP/MAP wiring. My engine is also worse when cold and worse with the A/C on. It stumbles at low RPM under load but gets better with engine temp. If i sit at a light and give it just a little gas and hold it at 1300 RPM the miss goes away but when the light goes green it will miss through 1st and 2nd gear. Not trying to thread jack but if i figure mine out it may help you. Im going to replace my MAP and look again for vacuum leaks. Mine is too obviously tied to me messing with my intake.
I have checked all the vacuum lines, map sensor (cleaned), IAC valve (cleaned), put in a new intake filter, compression test (consistent results), spark plugs, coil wires, coil packs, checked valve/retainers for recess/cracks.
My symptoms are NO CEL, puffing sound out of the exhaust, and the entire engine/car shaking, 99% of the time during cold/idle, most of it goes away after driving the car and it gets fully warmed up. VTEC strong and redlines 1st/2nd, lots of power.
I am getting my injectors cleaned tomorrow--I pulled mine out and they all had grime/dirt on them.
I seem to have the same symptoms as these threads, although I won't know for sure until I get new fuel injectors in--I will report back on the flow testing, cleaning, and re-install soon:
https://www.s2ki.com/s2000/topic/998...-s2000-solved/
https://www.s2ki.com/s2000/topic/495...-misfire-case/
https://www.s2ki.com/s2000/topic/292...t__p__10841583
08-09-2015, 11:44 AM
#22
I have an OBDLink MX which streams telemetry from the OBD port to my phone running Track Addict from HPTuners/Race Render. Just a cheap-o OBD scaner that reads data and codes. The sampling rate is so bad i cant even use it for good race track telemetry but it may be the track addict software thats so bad.
08-13-2015, 12:00 PM
#23
Thread Starter
Added ultrasonically cleaned fuel injectors, with new gaskets all around. Cleaned the injector ports in the manifold (lots of grime). Machine shop said the injectors were absolutely clean.
No change, lots of shakes at idle. No CEL.
No change, lots of shakes at idle. No CEL.
08-13-2015, 01:04 PM
#24
When all else fails, bad ECU. Your coolant doesn't have any oil whatsoever in it right?
08-13-2015, 07:37 PM
#26
Thread Starter
Bought a 2004-2005 new Denso coil pack and testing a cylinder at a time.
Switched out Cyl 1, then Cyl 2, no difference (shaking remains). Currently in Cyl 3 and it *feels* promising, will report back after more testing tomorrow. Wish me luck.
Can coil packs go without setting a CEL? That would be a first for me.
08-14-2015, 08:59 AM
#27
Thread Starter
Morning update, 100% cold engine (when symptoms are 100x worse):
New coil pack in Cyl 3 still, car started up VERY STRONG, and no starter grind/screech (first time that hasn't happened in 6+ months). No shaking at idle, warmed up to 3 bars.
Will keep testing, but I'm hoping this is it.
New coil pack in Cyl 3 still, car started up VERY STRONG, and no starter grind/screech (first time that hasn't happened in 6+ months). No shaking at idle, warmed up to 3 bars.
Will keep testing, but I'm hoping this is it.
08-14-2015, 01:55 PM
#29
What a mind f@#k cars are! The first time I turn the key after I R&R my air box and I get a misfire with no codes and totally unrelated to the intake/vacuum/MAP. The spark plug tube seal went bad and some oil got around the top of the spark plug murdering the coil. New seal and coil and everything is normal. Not any help for you OP but be prepared. When you find the issue it will piss you off and feel great at the same time. Good luck. Wanna hear something? Mine was also cyl 3.
08-15-2015, 04:47 AM
#30
Best way to check coil packs? I had something similar happen to me like it did to dead serious with the tube seals going bad. Oil on spark plug but didn't think it would have damaged coil packs. I get a rough idle at neutral and haven't figured it out since I rarely drive the car these days. Now u got me thinking if it's that