1994 Cobra Sluggish and Bouncing Idle

94CobraSvt · 09-16-2008

Hey guys maybe you can help. After being away from 5.0s for awhile I decided to go back to my roots and buy an orginal 94 cobra completely stock, down to the air filter w/93,000 miles on it. The car runs fine on start up for about 10 minutes and then begins to get sluggish until WOT. The idle on occasion will bounce and sometimes stall when at a light if i dont keep my foot on the gas. I listened/looked for vacuum leaks and cleaned the maf and the iac, but it seems like that may have only helped a little. It throws no trouble codes so I am puzzled. This is my first sn95 and I have no clue where to start next. Thanks for your time

v6stang3215 · 09-16-2008

My 95 cobra was also very sluggish when I got it. I gave it a full tune up and that did the trick. I would suggest doin that. Since your air filter is stock you might want to buy a new one. I have a brand new k&n drop in filter. If you want it send me a pm. I can't guarantee it but I think a tune up would help a lot.

94CobraSvt · 09-17-2008

Hey guys...I bought a new IAC and that seemed to fix the idling problem. It now runs awesome for about 5-10 minutes and then it will get sluggish again, I'll almost have no acceleration in the pedal until WOT. Its almost like a automatic with a kickdown. The car had a tune up the week before I bought, and I cant hear any vacuum leaks. Im clueless. Thanks Again!

Lopez16 · 09-20-2008

Try checking your spark plugs. I had same problem with my 98 Cobra and 2 plugs were bad.

delarosa121903 · 09-24-2008

even though it didn't kick out any codes, check the tps and have a fuel pressure test done along with a new fuel filter.

mpatt07 · 09-24-2008

Try the fuel filter. I had similar problems and the filter was the problem.

94CobraSvt · 09-24-2008

Hey guys I went down to advance auto parts and bought one of those actron scanners and it kept throwing all o2 sensor codes. Long story short, I replaced both and its like a brand new car!!! Runs so much smoother and there is no hesitation. When I pulled the old ones out they were white which confused me...is that just from the computer making the motor run lean cause they werent working right or was it something else?? Thanks again guys for the help