Engine is stumbiling

[A fireman]

Ok in the last few days I've noticed that once teh engine gets warmed up if I'm sitting at a light and lay into it ( about 25% or more) the car stumbles through first and a little in second. Also on a free rev it will do it unless i bring the RPM's to about 5K and clear it out. I'm little confused on what it could be. First thought was ignition isn't right but i can clear it out. Thanks in advance.

[cam98aro]

Re: Engine is stumbiling

Ok in the last few days I've noticed that once teh engine gets warmed up if I'm sitting at a light and lay into it ( about 25% or more) the car stumbles through first and a little in second. Also on a free rev it will do it unless i bring the RPM's to about 5K and clear it out. I'm little confused on what it could be. First thought was ignition isn't right but i can clear it out. Thanks in advance.

an engine needs 3 things to run, fuel, air, and a spark

first off, i would make sure the air filter is clean, i know it seems elementary, but it can make a huge difference

when was the last time the fuel filter was changed?

do you have access to a fuel pressure gauge?

theres so many things that can cause a stumble, in your situation:

warn plugs/wires/coil going bad
bad FPR
leakey injectors
not enough air getting to the engine (air filter, carbon buildup)
bad cat

i would try and do the air filter/plugs and wires first, since your problem seems to maybe the engine getting too much fuel, or not being able to burn all of the fuel

[nimrod.sixty9]

Re: Engine is stumbiling

No codes?

I second checking fuel pressure. Get it down to AZ and use thier PSI gauge and check specs. If its about time for a tune up then heres your reason to go ahead and do it...

[A fireman]

Re: Engine is stumbiling

yup no codes and its only after the engine has been running for a while. Just had it out today drove about 10Mi nothing but when i went to restart the car it rook about twice as long as normal ( started normally cold) and ran fine on the way back

[A fireman]

Re: Engine is stumbiling

ok well its still doing it. I've begun to notice its predominant if the car idles at a light before taking off.
fuel pump was changed about 15K miles ago, plugs and wires 20K( july 08) and the airfilter is a cone style replacement and was just cleaned. Im going to check the fuel pressure tomorrow ( first day off) is there anything else that can be though of? of and i checked my cat its not glowing or getting hotter then it used to.

[A fireman]

Re: Engine is stumbiling

swaped plug wires, checked plugs and ran an engine diagnostic and cant find anything. the plugs show a milky haze on the electrode which i have been told is normal for a clean burning engine. so i'm stumped
Edit: forgot to mention checked the fuel presure idle 38 and under free rev 33-35 psi