like the title says.....under acceleration i have a stuttering, misfiring situation happening. Only happens when below 3000 RPMs, 1/2 to full throttle, AND in closed loop.... Yeah that's the thing that f'n with me....when the car is cold it runs perfect, but when it warms up studda, studda. Anyone had a similar prob??

My guesses are.... Oxygen Sensor...clogged fuel filter.

need suggestions please....
Thanks

 

I would say FF. If possible just check your timing.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDm_jeremy &raquo;</TD></TR><TR><TD CLASS="quote">My guesses are.... Oxygen Sensor...clogged fuel filter. </TD></TR></TABLE>I've seen both those cause that same problem.
I also had that same exact problem with my car. After I changed the o2 and fuel filter, along with about everything else ignition. It turned out to be my less than a year old NGK wires .
Could also be a clogged injector.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jDm_jeremy &raquo;</TD></TR><TR><TD CLASS="quote">like the title says.....under acceleration i have a stuttering, misfiring situation happening. Only happens when below 3000 RPMs, 1/2 to full throttle, AND in closed loop.... Yeah that's the thing that f'n with me....when the car is cold it runs perfect, but when it warms up studda, studda. Anyone had a similar prob??

My guesses are.... Oxygen Sensor...clogged fuel filter.

need suggestions please....
Thanks </TD></TR></TABLE>

My car's the same way. Put a new fuel filter on it... fixed it for about a week, then it returned. Put new plugs and wires on it, still does it. I'd try and put a new fuel filter on it first.

 

First: Try unplugging your 02 sensor connector, if the problem is the same, most likely its your 02

Second: I would check your 02 circuitry. Let your DMM and helms diagram schematics lead the way. See if you can get the testing procedures for your 02.

Third: try borrowing a known good sensor

let us know!

 

JESUS! I wasnt even thinking... CHECK UR TPS!!!
that is the easiest sensor to check. 5V reference, Ground, Signal.

also, check for soft codes that might be stored in the ecu use a paper clip on the 2 wire jumper underneath the glove box to pull the codes (if u got obd2, ur SOL)

to check the TPS:
Signal: KEY ON ENGINE OFF, positive lead on red/black, negative on known good ground (- side of batterty) Should be 5v
note: the sensor needs to be connected to the connector clip (use a pin to probe into the connector)

Reference: KEY ON ENGINE OFF, positive lead to the yellow/blue wire and the negative lead to the green/black. once connected it should read .5 volts. SLOWLY increase throttle position. the voltage should go up with the throttle plate opening. If you see a voltage jump when you are doing this, have it further inspected, with someone with proper tools (like a scanner or a Vantage). But if the voltage doesnt move at all, then your sensor is f'ed. replace it. good luck bro. IM me if u need more help.

 

Check your ecu mine went bad and it did the same thing.

 

Thanks everyone ....i think i'll try to start at the least expensive fix and work my way up.....fuel filter first, then Ox sensor, and might as well change plugs and wires while i'm at it.........and hope like hell its not the ECU

i'll post what i find

 

the thing that's i dont understand is why it runs great in open loop [ when cold ]??

i think that would eliminate the fuel system all together....weird problems suck

 

^^bump^^

 

did you acually try testing your TPS????

 

My car used to do that but only at 100% throttle, and 95% i was ok. It wound up being my tps sensor.

My friends GSR also had the same problem but only on occasion. It wound up being his sparkplugs.

I would check fuel filter though and then injectors. Sometimes at high rpm fuel is flowing fast enough to not be affected much but at low rpm the filter could be affecting it. There is my 02 hope it helps.

 

tps sensor is a good idea....haven't checked yet been busy with work.....will check and post

thanks

 

thanks brah...yeah, this is one of those problems that could be anything.....SUX

 

Alright, here's the deal.....tomorrow I've got one shot at fixing this thing, one item [ limited cash b/c i'm buying a house ] if the TPS is good, i could either get plugs & wires, or a fuel filter, or a OX sensor..... not sure which one to get, but i've got one shot for two weeks so i better make it count. if not i'll just drive along real slow on take-off. What do you guys think would be the best bet?

 

^^

 

buy something u cant test, fuel filter should be first, assuming you have already checked the plugs and they are ok. (when was the last time the fuel filter was replaced, its supposed to be done every 30k) i would also check the air filter.

to check the injectors, put the voltmeter on the ground side of the injector (YES, THE GROUND SIDE!!) it should read 12v consistantly. make sure to use a pin to probe the injector connector

although i really dont think it's an injector, i just thought i'd let you know if u wanted to test it while your in there

EDIT: i really dont support throwing parts at cars, i sugguest you
first: check air filter
second: look at plugs (btw: are they the proper heat range???)
third: test 02 sesnsor, tps, and map sensor
fourth: if you havnt found a problem yet, take it to a shop and pay a diagnostic fee, it will save you the money from throwing parts at it.

 

Update: gave the car problem more time to present it's self and realized that what was really happening was my #4 cylinder was dropping out on spark advance....Replaced plugs and wires.....BING, BING: we have a winner!! #4 plug had a crack in the porcelain and was arching through. Everything else checked out fine.. PROBLEM SOLVED Thanks everyone