bogging and loss of power

[1.8laser90]

hey guys i have a 97 gs 5 spd. ive owned it for about 3.5 yrs and have some decent mods to done to my car and for some reason my car seems to be getting very very slugish.

heres my current mod list.
msd wires and coil pack, ngk plugs (have about 25k on them will be changing them tom.) CAI, header with full straight threw 2.5in exhaust with resonator in cats place, howell crank pulley, full topend rebiuld with shaved head and 3 angle valve job(about 25k ago), completly tken out egr system, and howell autmotive 97 only ecu.
Ive been running premium gas for about 2 yrs and add some octane boost and injector cleaner when i go on long trips. I checked my compression acouple months ago and it read 180 across the board. The bottom end currently has 186k miles and the oil has been changed ever 3k or every month (i drive alot) since ive owned it at 139k.
lately it seems to run horrible. Its been getting worse atleast it seems that way but ever since ive done alot of these mods it just feels like somthings holding it back alot. I seem to have good lowend torque. when babying it i have no problems with keeping the rpms under 3k and still acc. smoothly and it actually feels like it has something until i put the peddle to the floor and it pretty much says #### you . when goin from a dead stop and full throttle i feel a power loss from 3k to about 4.5k and you can actually feel then engine kick back then start to go back in. You cant notice it from 1st to 2nd but other gears its very noticable. In order to get acceleration out of it i really have to be screamin in the high rpms to feel like im going anywhere. If im on the highway (which is 80% of my driving) if i have to pass a car when doin about 65 70, droping to 4th barely pulls i have to drop to third in order to get any pull. its kinda hard to explain but i have to start with my engine screamin hi in the rpms to get accelaration. If not it runs like a dog and sounds like its chokeing. It never back fires or spits or sputters its just like somthings holding it back.

I hope i was detailed enough but for the mods i have it should not run like this. My buddy has a stock rs and it just feels so much smoother and i guess free compared to mine and his is completly stock. help would be very apprecaited.

 

[tazman_tn]

this may sound basic, but when was the last time the fuel filter was changed? also if it is new, you might need to check the fuel pressure. to me it sounds like it could be stopped filter or weak pump

 

[99RedGs]

Honestly it just sounds normal. These cars are not speed demons, and based on the mods you have done you probably didn't really net much power. Do you carry a bunch of crap around in your car? Get rid of any extra weight you are carrying. Also stop using premium. It isn't netting you anything except less money in your wallet.

The reason your car feels sluggish at lower rpm's is because it is making less power there... (Tq x RPM's) / 5,252 = Horsepower. Less RPM's = less power. I believe the powerband for these cars is from 3500-6000ish. That is why you have to downshift to 3rd.

 

[1.8laser90]

this may sound basic, but when was the last time the fuel filter was changed? also if it is new, you might need to check the fuel pressure. to me it sounds like it could be stopped filter or weak pump

i replaced the fuel filter about 3yrs, soon as i got the car cause it was leaking. ill check my fuel pressure to make sure its decent. never thought about that.

as for extra crap. i try to keep it emtpy as posible. spare tire and all that is taken out.
i run premium fuel because i have the howell automotive race ecu, premium fuel is required.
i understand about the powerband. But when reving threw the rpms i can actually feel my engine kick back and i can hear it also do it by the change in my exhaust tone. it doesnt like stutter or backfire but it acts like ive let up on the throttle and then went full throttle again.
Just the other day i was driving and i gave it about 90% throttle to go up a hill and ALL my power disapeared. My engine pretty much died for about 3 seconds until i downshifted and everything came back when rpms hit 4k. But once again it never backfired stuttered or anything. Its never done that before which is why its really starting to bother me. Could cam timming have an effect like this? cause when the head was rebiult i had it shaved but i never put ajustable cam gears on. Would getting some and ajusting that smooth it out alittle bit?

 

[Fotowntalon]

he said he has a 97 gs= 420a = 2.0 liter. his name states an entirly different car and motor. As for the power, i think you are dead wrong on stating its not a speed demon, granted all motor requires much work to hit 13's it iss possible, and for a guy to suddenly notice a drop off is a completly different subject.

First off any CeL's? Secondly, i would also replace the fuel filter, sounds like you are lacking in that department. I really hope there is nothing wrong with your transmission... Also could be a small chance your catalytec converter is getting plugged up, but from my experiance that was a is more extreme loss of power.

 

[RoninEclipse2G]

I had almost the exact same issues a few years ago, the car would lose power and occasionally stutter between 2500-4000rpms and I had to rev it to high heaven or keep it below 2500 to have any power. Cruising at partial throttle didn't matter much, occasionally it would hiccup but it was hard to differentiate from road bumps.

It was a gunked up fuel system for me. I started with a fresh fuel filter and that helped a bit, shrunk the window from 2500-4000 to 3000-4000. Then a friend of mine suggested getting the injectors cleaned. Mitsu dealer wanted a couple hundred to do a cleaning and diagnose the issue. Right... I'm a poor bastard. So I bought a 5 gallon gas can, a quart of Lucas fuel cleaner, some Sta-bil, a can of BG44K (friend at a dealership hooked me up on that one), and a gallon of E85. I mixed it all together in the gas can and topped it off with regular octane (85 here in the mountains) poured that into a nearly empty tank and ran the PISS out of the car.

hesitation was GONE by the next fillup