when my car is cold, it idles erratic (500-1000rpm) it normally idles about 1000rpm. it doesnt like to take gas, and stumbles/surges from idle to about 2500rpm.
WOT performance is good, just part throttle. the problem is more noticeable when the motor is cold, but is still there after warming up. i have no SES light.
i have new MSD wires/ cheapo autolite 106 plugs.

here's my thoughts.
1. my plugs are bad for some reason...
2. my opti is starting to crap out (83k miles)
3. my Boosch o2 sensors are going bad after a year.
4. i dont think its the stock coil or wire....

let me hear your thoughts.....

jesse

 

hey, I just re-gasketed heads (for different reason) and had the problem before and after the reinstall (i bent a valve and reinstalled heads, and above). I am not sure what it is either, so if you find the problem please tell me. I am thinking fuel pump?? but I just cleaned IAC, checked TPS, everything... I have only had the problem after the cam install though... maybe stock tuning w/ cam does that?? **also, w/ the rebuilding of the head, I replaced plugs, wires, opti is maybe 1yr old?, everything else has been checked/replaced, and this only happens on STARTUP for me, not sure if its same for you

ill be checking in, hope you find the problem!

 

i doubt its my fuel pump i put in a walbro 255, and my fuel pressure is constant at 46psi.

 

check for arching in the wires in the dark. Dont forget to look at the coil wire. Try to do a search along the lines of "low RPM stumble" or miss. Just see what has turned up in the past and what was the solution. I'm a bit too tired to search right now, but that might be a good start as far as getting ideas.