i normally try to take it kinda easy on my car and not take it higher than 5000 RPMs but today i was playing around with it today and wound it out to 6 a couple times.. i didn't notice it in first because i was just spinning like crazy but in second and third i noticed when i got around 5200 or 5300 rpms it lost a little power. the car has only 55000 miles on it but i think it still has the stock spark plugs.. does anyone have any idea what would cause this to happen? bad plugs maybe? the car is still all stock except for a K&N air filter which was in it when i bought it.

 

if you rarely drive it like that, sometimes it takes a WOT blast or 2 to "clean it out" if you know what i mean.

other possibilities are plugs (as you stated) or fuel starvation. could be a clogged fuel filter or dying fuel pump.

check your fuel pressure

have it tuned...after a tune up.

 

Maybe your butt dyno just needs recalibrated.

 

haha....a loose bearing perhaps....

sorry...couldn't help myself

 

okay i removed the muffler today making room for the b&b i just ordered and i mashed on her again and i could hear it breaking up at about 5500

 

might be running into valve float

 

i think im going to try a new set of plugs first. what kind do y'all recommend?

 

You could possibly have some bent pushrods. My car did the same thing..wasnt sure what was going on untill a few weeks later it started ticking. Turned out i bent some pushrods. Put in some hardened ones and it solved my problems.

 

plugs...keep it simple

ngk tr55s...gapped to .060"

$2 each

no need for $10/per plug platnum, irridium, gold, titanium or whatever other fancy crap they've concocted.

but while you're working on the car....i still suggest a $10 fuel filter.


find someone with scanning software and see if you're getting KR or misfires.

 

Its a stock car, it will naturally die off up top like that. Best you can probably do is a basic tuneup. Replace the air/fuel filter, plugs, and run some injector cleaner. Check the plug wires as well.

 

sweet thanks guys

 

dumb question but does everyone gap the plugs at 60?

 

Seafoam her too. Couldn't hurt.

 

i bought my new plugs today and got a fuel filter too.. i'll probably just wait until i get my headers before i change them and just do it when i have the manifolds off

 

Lately I've seen alot of bad mass air meters which do what you describe.Easy to tell if you scan the 02's.They will go to 0 volts up top.Lean enough to not even hurt the motor.

 

 

My TA is doing this right now and I suspect mine to be a fuel pump because it starts getting lean towards the 5500-up and my injector duty cycle is 128% at 6400 rpm's and the afr is around the 13.6-13.8 at WOT (which isnt good!!!). I know for a fact I can't be maxxing the injectors out if they have the full 60psi of fuel pressure but I think in the upper RPM's my pump is crapping out on me and dropping fuel pressure. So a new Walbro will be going in the car within the week and then retuned. BTW, stock F-body fuel pumps are junk!

 

i can add another to the fuel filter/injector cleaner.... a while back my car would die off at about 4000 rpm's and was just a turd. the car had about 120k on it and i noticed that the fuel filter had never been freplaced. i went to advance auto purchased some gumout injector and valve cleaner and replaced the fuel filter.

let her sit ideling for about 10 mins. let took her for a spin and WOT, i could actually feel her waking up again. it was def a kick in the *** for the car.

 

nice! i'm kinda partial to lucas fuel treatment so i might try that when i put the new filter on. How bad are the fuel pumps to replace?

 

hahah


unless you cut a hole in the rear floor of the car....you have to drop the rear axle and then drop the entire tank.

not easy from a logistics standpoint...but not really mechanically difficult.