Help me solve my power problem

[Synned]

Okay guys so I have been having a problem with my car. Sometimes it wants to run great...I think its when the engine is cool (maybe when transmission is cool). Then after I drive for a little its pretty much crappy. But the thing is the missing power is only below 2k rpms. It's weird. So far what I have done is:

Tune up...spark plugs (WHICH AREN't GAPPED CORRECTLY), spark plug wires, dizzy cap and rotor,
cleaned MAF, IAT, and the thing on the throttle body held on by two bolts. lol.

I've also noticed a surging idle...its very bad...but again only sometimes. It hesitates when I get on it.
I'm thinking either o2 sensors or the fact that my spark plugs are gapped incorrectly. No codes. Help!

 

[Synned]

Noboy has any suggestions? I guess I'll go ahead and replace the o2's and spark plugs with gapped ones.

 

[DarkProphet]

check for vacuum leaks, they could cause a problem like that. You might want to try spraying carb cleaner, or starter fluid or any similar explosive canned fluid around vacuum lines, if your car pics up some rpm's you might have a leak there. Just an idea, good luck

 

[Synned]

Okay i'll try and do that...do I just spray it on every line? How do you know which are vacuum lines?

 

[trelz4]

I Dont Know Much But Ive Had My Share Of Problems Trick Flow Told Me That Could Be Vacuum Leak, The Tps Being Off Or Timing
My Tps Is Now At .98 No Vac. Leaks And My Timing Back At 10deg And I Put A Custom Chip In Comp To Change Timing Might Not Be Much Help But Thats What They Told Me I Had To Have Someone Else Do The Work For Me

 

[Synned]

Well I changed the sparkplugs for gapped ones and it felt great...for a little bit. Now im 100% sure that the problem only happens once the car is heated up and driven for 30 minutes+. Why is this happenening? Is it the o2's? Because they don't get used till they are fully heated? No codes...Would the transmission send codes if it was slipping?

 

[ROLLIN5.0]

All cars will have more power when they are cold. Colder air = more power. I slide sideways from time to time leaving the neighborhood (on accident), but once the car gets hot, it feels like a dog. You could have something else going on, but to some degree it is normal.
Brandon

 

[Synned]

So this means if I drive to the track i'm screwed...unless I let it cool for an hour and a half. But the car does hesitate when I get on it after it warms up. When I put the pedal down hard it wont go anywhere then the rpms will start to climb. It's weird. Maybe its missing but I don't know how to describe it.

 

[Synned]

Okay this is starting to be a serious problem....the car feels great in the morning...but even after it sits for 6 hours while im at school it feels horrible. I hit the gas and it will hesitate before it starts to move. Badly. Can it be the o2 sensors?

 

[Synned]

Wow guys, replaced the o2's. Holy ****! THATS WHAT A 5.0 IS SUPPOSED TO FEEL LIKE!
SOLVED!

 

[Green 94 5.0]

strange. normally when the oxygen sensors go bad, you get an intermittent check engine light along with a stored code. glad to see the problem is solved though.

 

[Mustangless]

Did you mpg get better also? I got a code for one of mine a while back and replaced it only. Maybe I should replace the other

 

[Synned]

I dunno, see my problem was only happening after driving a little bit, I'm assuming because the computers dont look at the o2's untill after warming up. So if you just turn your car on and you feel power (e.g. you can chrip off the line) try the o2's. I noticed a HUGE increase. I can burn out at any stoplight, any time of the day!

BTW I had no codes.