Help!!! please. im freakin clueless.........

[highintheskyy]

ok, i know this thread may seem very familiar, But im stuck in the very same position i was in before except i just spent about $180 more then the last time i posted and i still have the same problem with my car. Last time i posted i got exactly what i was looking for (advice) and i tried alote of the ideas you guys offered, but they didnt work. So im gunna try my plea for advice one more time.....please, any advice is better then none Nissan 240sx 1995 automatic 86k, stock

Symptoms: (all of the symptoms only occur when the car is warmed up.) In Drive at idle, the RPM's go up and down, Which makes the engine and the entire car shake badly. If i put the car in Park or Neutral it "kinda" stops shaking. Then when i press the gas it will kinda stutter and sputter, throughout my acceleration up to 30 mph, then it seems to go away at high speeds. The wierdest thing is even if the car is completely warmed up, it wont happen all the time, the shaking and sputtering seems to come and go..... My ECU is also reading closed loop. (whatever the **** that means) Parts Changed within the week by proffesionals: Knock sensor, Crank angle sensor, MAF,Oil, Spark Plugs, & Oxygen sensor. (my ecu read off a knock sensor & crank angle sensor this week so i had both changed.) Please, please somebody give me some words of advice....even if ur just guessing, throw me some ideas.....ive gone to different mechanics, both did diagnostics and came up with what ive changed recently....In other words ive spent about 400 dollars this week and i still havent fixed **** yet....

[bigdawg182]

have you replaced the coil yet? sometimes when they break down, they act up when they are hot, but run fine when cold. you mentioned plugs, but didn't say plug wires, but i'm assuming you changed those too.And a minor technicality... did you disconnect the battery so the computer could reset after installing those new sensors? Hope this helps.

[bigdawg182]

also, check the catalytic converter and try bypassing your EGR valve.

[180fan]

so if it's only happening when the engine is hot, have you tried switching out the coolant temp sensor?

[barndweller]

its either the fire or the fuel and it seems as if you've given the electrical a going over,swap that filter and fuel pump and put some injector cleaner in the tank, crank it up in the dark an take a look to see if the plug wires are arcing. maybe that alternator ain't putting out at low rpm.

[kassed33]

try doing a injector cleaning, it sounds like its not getting enough fuel, and i goes away at higher speeds cause your pushing more fuel through them so its not as noticable, and Closed Loop operation is when the ECU uses the oxygen sensor to tell if the fuel mixture is rich or lean and is uesd to adjust the A/F mixture.

[driftedsilvia]

check your cooland and tp sensors but make sure that they get fully tested and thet you "mechanics" arent just guesing at it by the computer codes and throwing parts at it untill it works.

[hboninc]

disconect the pipe that runs from the exhaust mainfold to the egr. then see if the problem gos away............because if the egr is stuck open your engine will lean out(to much air not enough fuel)............ CLOSED LOOP is the basic engine management in which in put from an oxygen sensor allows the engine control computer to determin and maintain a nearly perfect air fuel ratio. the engine will not go in into closed loop untill the coolant sensor tells it the enginehas reached operating temperture, and the computer is receiving an input signal from the oxygen sensor. as soon as the system enters closed loop, the computer beging to vary the fuel mixture based on inputs from its sensors..

[hboninc]

also check your throttle body. if its dirty clean it with some carb cleaner

[DukeBoy]

There are a lot of things that can be checked:Check your IAC (idle air control) valve. They can usually be removed and cleaned with brake cleaner.Check your timing. Check your fuel pressure regulator or replace it with a working one. You might not be getting enough fuel or too much fuel. Did the mechanic that changed ur plugs show them too you or say if they were fouled because of running too rich or if the motor was running lean?Is your temp gauge reading high? If it is, your thermostat might be bad and the engine is overheating. You might have to bleed any air that might be trapped in the coolant system in the engine if it is overheating. I know the SR will shake and sputter if it gets too hot. Do you notice any smoke coming from the exhaust(white, black smoke)? Any radiator problems in the past? Do you notice your coolant level low or the radiator bubbling? Did you have too much oil when it was changed or any foam on the dipstick? If it is, you might have a bad head gasket. It might be a long shot, but check ur vacuum lines too.

Keep us upto date on everything. Goodluck

[wesae86240MK2]

im thinkin it is either your coolant temp sensor or it is your egr valve.

I had a camaro that did that and sure enough i needed a new egr valve and o2 sensors so try that if not it might be your throttle body have you tried adjusting it that also might be part of the problem well let me know if any of that works.