pontiac

iTrader: (4)

OK, drivung car to work this morning, car is running fine, get on high way still running fine, then crusing in 6th gear car just loses power, fells shacky, puch in clutch idels but at like 500 and really shacky, no power like a big miss, but is not throughing any codes, what could it be?? no bad nocking or vaulve noise, so probably Fuel or spark, but where?? any ideas would be great.!!! car has 109,000 miles, mods in sig.

brad8266

iTrader: (23)

Start by checking the ignition system and then the fuel system.

pontiac

iTrader: (4)

any ideas where to start?? on doing that?? like what is the most likley?

MCBRIZ28

iTrader: (2)

Check fuel pressure first a really bad igntion problem would most likely throw a ses light.

pontiac

iTrader: (4)

Ok checked gas for water, nothing.
Started it up and pulled each plug wire and each one makes a difference, so I am guessing not plugs, plug wires, or coil pakes, unless i am missing something. what next or any ideas

pontiac

iTrader: (4)

bump1111111

SSpdDmon

iTrader: (10)

My guess is fueling. Do you have a scanner that will let you read fuel trims and monitor NBO2 activity? You're fuel trims could have spiked or dropped off causing the symptoms you mentioned.

Quickin

When did you change the fuel filter last? Sounds like perfect symptoms for a clogged/dirty filter, and thats just when it'll act up, under a low, stable amount of throttle like while cruising in 6th. Does it happen under WOT runs? Won't get a code for it either.
Bad O2 sensor will also cause that and they WILL NOT always throw a code, mine were both bad and I had no code but they did show up bad with an OBDII scan.


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pontiac

iTrader: (4)

Have not tried WOT, i was driving it and then it started the stumble I parked it and trailered it home, and it has a miss at idle. I can try a filter, thats easy. I can try and drive it when i get home but i really would rather not let it warm all the way up with this miss. just to try and floor it with the miss too. will that not hurt something? I have a code reader thats it. I do have a spare 02 sensor i could swap out and see if that changes anything. I was thinking about disconnecting one injector at a time to see it that changes anthing like i did with the plug wires. ?? any suggestions? or at least and order of operations.

pontiac

iTrader: (4)

Can an o2 sensor, cause a direct miss? or a fuel filter? sorry should have asked that in earlier post

Quickin

Bad O2 sensor(s) will cause all kinds of crazy ****, including what feels and sounds exactly like a "miss". When my O2's went bad (well really it was the wires) they both did at the same exact time, because a mechanic reinstalled my wires and laid them up against my headers. The wires melted at the same time on both sides. While on the highway, cruising steady at 70mph, the car just slowly started to stumble and lose power. Nothing crazy bad, but just like it decided it had enough and didn't want to run anymore. But on my way to the shop to have it checked it was missing, spitting, back firing and then would just humm along steady but stumbling a little bit.

The reason I said do a WOT run, or maybe just a nice strong run is to see if runs perfectly. If it does than its most likely a clogged fuel filter or other fuel delivery issue. Because under WOT or close the fuel pressure is much higher than at cruise or casual city driving, and the fuel will get pushed through a clog or dirty injectors.

A scan will show the bad O2's though, so do that first. If the O2's are good I'd change the filter, than I'd run a can of Sea Foam through the gas tank.


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pontiac

iTrader: (4)

Thanks i will play with the o2s and see what i find, try a fuel filter agian too... please check back when i try these, have to get this thing runnng again.