hesitation still

[clickdoc]

ok guys -- this is either going to be a really good laugh for you mechanical guys or you are going to write back and tell me i am a genius - so i originally thought it was water in my gas -- nothing has helped with that -- it hesitates when it is warmed up -- key point -- all new injectors -- o2 sensors - maf -- all the usual suspects -- but it did feel like it did when the o2 sensors are bad -- so i opened my hood -- started looking -- the o2 sensos wire was sitting against the headers -- un insulated -- would this cause a prob -- it seems that it would as temps went up -- anyway i jury rigged a dual layer insulation from that stuff you cover wires with and use a tie to pull the sensor wire away from the header -- ok -- time to vote -- genius or idiot -- PS i had the work done at ultimate z -- should they have caught that ??

[KrazyKyle]

Did it solve you hesitation problem after doing that?

[clickdoc]

no hesitation still there -- i am ready to shoot my car !!!! it still could be water in the gas that hasn't cleared -- so the extra work i did at least will keep a meltable wire off the hot header -- i am waiting for NSR32 to reply -- i am interested to see if he voted me genius or idiot -- i think i already know the answer to that !

[F4TJ0N]

The reason for your hesitation is that your knock sensor might be bad. You are going to have to do a Diaginostic test or if you have OBD-1, do the the blinking light test. I beleive code 34 (3 long blinks, and 4 faster blinks) is the a bad knock sensor. Im in the middle of doing that right now, and that intake plenum is a real PITA. Search the Diagnostic test to see procedures of finding trouble codes.

--Jon

[Srowlands]

Could also be a possible air leak. Also, it could be the fuel pressure regulator or even your purge canister.

[clickdoc]

no -- not the knock sensor -- already replaced

thanks

[clickdoc]

So i am going to the car doctor to get an ECU diagnostic -- any other guesses before i have the answer - my guess is that the header ruined the wire coming off the o2 sensor -- almost everything else is new or has been replaced -- the o2 sensors are only a couple of months old -- replaced with the header install -- will report tomm afternoon -- good luck brainy z guys !

[KrazyKyle]

Mine had a really bad hesitation at low rpms. It would buck and sputter until it got to about 3500 rpm then it would smooth out, but you had to drive it balls to the wall for it to drive right. It would also die at stoplights if you didnt give it some throttle, and also if you coasted with the clutch in. I dreaded having to drive it every day. I changed my pcv valves out and it solved the problem though. It purred like a kitten after that and had a rock solid idle at 900 rpm. It may not be the same problem, but it worked for me. When I took the old valves out there were filled with an oily carbon material.

[evildky]

the looming you put on your O2 sensor wire will melt if it touches the exhaust manifold it's not rated for such high temps, if the wire is melteed you could have a problem but i don't think it would cause much running issue, maybe just a bit rich

how on earth would wone go about getting water in the cas tank? I highly doubt this is the problem

have you checked all the coil pack connectors? how do the plugs look? injector connectors look ok? CHTS? if it runs fine cold and starts acting up once it's warmed up I'd go for the CHTS

[clickdoc]

coil pack connectors are new -- spark plug are new -- don't know what CTHS is ?? thanks

[clickdoc]

well another update -- not PCV valves or hoses -- talked to previous owner -- new within the last year with all new hoses -- looked at the factory manual codes listed here http://zhome.com/ZCMnL/PICS/he....html -- it looks lilke i should have it narrowed down to three things -- because in addition to hesitation i also have surging -- the factory lists: 1. ECU 2. EGR 3. o2 sensors which are new - but previously i noted one of the wires was touching the header

can't wait to go in today and have it checked ~!

thanks

[evildky]

CHTS = Cylinder Head Temp Sensor

[clickdoc]

ok guys

the final verdict -- it was the o2 sensor -- just had them replaced less than a year ago -- so here is the question for the professional -- if the o2 sensor wire was sitting on the header -- but did not burn through the wire -- could it still cause the o2 sensor to go bad ??

it is running great now !