jerking/rocking/hesitation at idle

[NateB29]

so i am done putting everything back together after changing my knock sensors and gaskets. I also changed my coil packs and spark plugs at the same time because it was misfiring before i started the repair. used oem everything. took it for a test drive and it was doing great for about 20 minutes... then i noticed some hesitation when i came to a stop and eventually it died. i could start it up and once it was driving it does ok but the moment i come to a stop the engine is rocking pretty good and and the rpms drop with the tcs and slip lights coming on. when i got it home i noticed the little plug that goes into the air filter intake from the maf was dangling out but when i put it back it it did not help. from research this sounds like a bad MAF sensor but i dont know... any insight would be appreciated

[skyvette427]

Sounds like a MAF issue... mine went out but it would jerk/hesitate the whole time... i dont recall the car dying though... also could be a bad/defective coil.

Is your Check Engine light on?

[NateB29]

no check engine light. I just replaced all 8 coils with oem hitachi ones and ngk oem spark plugs

[3Q Jay]

could be a lot of things. what diagnostic tools do you have? Consult (like)?
what did you do for plenum cleaning while everything was apart? did you pull the nasty EGR tube out of the upper plenum?
check for vacuum leaks.

[NateB29]

i have no diagnostic tools besides a obdii scanner, but there is no cel. i cleaned the throttle body and i cleaned the plennums as best i could. where is the egr tube? is it that metal tube that screws into the back of it? if so yes i had to pull that to get the plenum out...

[3Q Jay]

EGR tube comes out the back side of the upper plenum. You don't remove IT to get the plenum out, rather, you MUST remove the upper plenum to get the EGR tube out. hope that makes sense.
could be that you merely loosened, and now there is crap that is in the intake valves, or has fouled a plug. Not bashing you, because it's always easier in hindsight, but why it can pay off to spend HOURS hand cleaning all intake components to spotless.
this won't be so easy without a way to see what the ECU is seeing/doing.
I'd measure your TPS and verify that it is EXACTLY 0.44v at hot idle.
Then tweak your IACV/AAC so that you are about 575 RPM hot idle park ac off(will be a gueess again base don the dash tach resolution) with the electrical connector unplugged from the AAC. then when plugged in it should be an almost imperceptible blip up to 625.

[NateB29]

how would i measure the tps and tweak my idle air control valve when the rpms keep dropping while its idling?

[3Q Jay]

you can set the TPS with key on engine off. but must be fully warm,otherwise the cold idle compensation will cause bad reading.

[NateB29]

ok. i found an oem maf sensor out of a wrecked car on ebay for $60, figured its worth a shot since its a pretty good deal, hopefully that does it, if not then i feel like i will have a lot of work ahead of me... will update

[3Q Jay]

well, i won't say it's not the MAF, but I will say that if the symptoms are new since the work you did then you might first look to what could have changed. surely the MAF did not?
also, your MAF is the same as the 95-99 maxima/i30. there are a lot of them out there....

[NateB29]

so to update for future diagnosis... i had overtorqued my lower intake plenum and cracked my manifold gasket. i didnt torque them to factory specs first time around and it cost me... but now that everything is fixed its running super good