well, so far i have done a ton of shit to this car to attempt to fix it,also to make it faster, and stronger.

so far, the engine is completely rebuilt, timing is perfect, compression is perfect, but i still get misfire after the car starts to warm up, with any throttle past maybe 1/8th throttle. and it will misfire from about 2,000 to 4,000 rpms.

i have replced:
-engine
-O2 sensor
-Spark Plugs
-Spark Plug wires
-Ignition Coil
-Test Pipe
-Fuel Filter
-random other little things

what else can it be????

my spark plugs also look like they are running really lean.... any ideas???

LMFAO...

"i have replced:
-engine"

now theres a fix you dont see often. ;)

fuel pump perhaps? i was getting severe hesitation/misfiring at part throttle when my grandmothers fuel pump went out on her neon. the fact that you are running lean is the only reason i suggested this.

definetly check the fuel pump, also check the injectors get an injector cleaning done at a shop its a can of cleaner that is pressurized through the fuel rail that the engine runs on for about 5 mins or so that cleans the injectors. not no bottle of cleaner in to the gas tank shit

anyone think it could be the fuel pressure regulator?

from what i have heard (no direct experience), but whe a FPR goes bad it shuts in the most "open" position, so lean conditions wouldnt be present. not sure though.

ok, so far for my lean mis-firing problem, it could be either a bad fuel pump, or injector/s?

Injectors or Idle Air Control Motor. Or the wiring to the injectors or IAC. Check those things first!

well, it cant be any of the wiring, but also we have noticed that it will only misfire after the engine has been ran for a good 10 - 15 mins...... anyone know what could cause this? also i think im gettinga error code for the engine coolant temp sensor, but if that were bad wouldn't that mean i would be burning rich?

nvm about only doing it after its well warmed up, it is doing it all the time now.... anyone think a engine collant temp sensor can cause me to run lean?

are you SURE you are running lean?!?!? the coolent temp sensor makes perfect sense for your problem, but the lean thing is baffling.

my spark plugs are white! :( that would mean its burning lean, right?

how much did you gap your plugs?

around .050, but no matter what i try gapping them to, it still misfires the same.... but i just got done installing a new ECT sensor, ill brb, and see how the test drive goes.

STILL NOT WORKING!!!!!!!! THIS SUX. Here is my list so far:

-engine
-test pipe
-coil
-wires
-plugs
-O2 sensor
-ECT Sensor
-Cleaned all connections
-Fuel Filter
-other random things checked


im stumped, but my car is burning lean, and is misfiring at about 2K-4K rpms. it cant be injectors, because there is no way that would make ALL 4 cylinders misfire. i am gonna give it very soon, i need help

bump

check your fuel pump and relay, as in ohming. This is a must when determining the misfiring problems. Pick up a haynes and go at it.

I recently developed this problem again, and fixed it.

Before I replaced plugs/coil/wires.

I took out my old plugs and put new ones in, but gapped them at .045 instead of .050... Measured my old ones that WERE at .050... .053, .052, .048, .048...

a couple of them came out VERY white, but the other two were fine, I'd double check, but that was a couple of weeks ago, and they are in the garbage, and I'm no garbage picker.

Its not the fuel filter or the plugs. i have the SAME problem. my thought on it was oil leaking into where the plugs and wires meet, and in the 4th cylinder head.

yeah, that will cause misfire, but thats not whatys causing mine, I will give anyone $20 to figure out my problem, because i cant figure it out, i might block off the EGR today and see what happens, but i have a whole new engine and it still happens to me, so i dont know whats causing it.... just remember, $20 to whoever can guess the problem.

well, here are some pics (not great quality, sorry) of my spark plugs, it looks like 2 and 3 are running a lot more lean than 1 and 4 ????






edit: i bought those spark plugs last night BTW

anyone kno what is left that could be wrong.....

you shouldn't go any farther until you take care of the coolant temp sensor. if it is out, the car will run a little lean while cold, but VERY rich while warm. the ecu will go to a preset 75 degree water temp to keep things safe when the sensor is malfunctioning.

tell me, does your cooling fan come on when the car has warmed up?

i already replaced my coolant temp sensor.... i have no idea what to do.

IAC Valve or Injectors. I have both for sale. See my ad in the For Sale Forum. The IAC is on the throttlebody. Also make shure you have all the vacuum hoses hooked up correctly and they aren't leaking. Injectors can make your car stutter and misfire, while the faulty IAC causes a "cam" like feel to the car.

what do u mean a "cam" like feeling?

how do you know if you are lean or not? do you have an A/F gauge?

"Cam" like feeling means a lopey idle. A rough idle.

hey, my idle is a lil rough, and lopey :( also you can tell your running really lean, when you just buy spark plugs, and by the end of the same day they are completely covered in white deposits :(

do you have any cel? is there any codes?

i dont have anymore CELs.....

I know I had some problems with plug wire to plug connections. check all four plugs for any kind of abnormalities. This is what my plug looked like after few days with new plugs, wires and coil. I couldn't figure out why I was backfiring, but then I found this.

Look at the plug. I guess it was shorting through-out the boot then through the electrode(if that's what the tip is called). I guess it wont hurt to check.