Loss of power at high revs

[Nice Guy Neil]

Hey folks, I've got an 88 accord Lx-i. Pretty good condition, 173k miles. The car feels pretty powerful below 3000 or so rpms, but after that, the power seems to stay level rather that increasing as you go up. Since it's supposed to develop max power at 5500 rpms, it seems strange. I've recently replaced the fuel filter, air filter (K&N), spark plugs, and plug wires. I know it's not all that fast of a car, but I'd like it to be as fast as it can be. Any ideas on what the problem could be (besides no VTEC ? :) ) ?

[A20A1]

Vtec :P

Maybe you have a ignition problem... distributor... or timing... or somethings wrong with your secondary throttle plates.

You won't notice HP the way you are describing... what you would feel was the torque... which is usually lower in the RPMS... and isn't much to begin with.

[Nice Guy Neil]

Yeah, but the torque tops still tops out at 4250 I think it was. Anyway, what are those secondary throttle plates you mentioned?

[TheSummoner101]

Yeah, but the torque tops still tops out at 4250 I think it was.
the max tourque should be when at around 2500-3000 rpm. torque is what u feel when u step on the pedal and u find your self half way stuffed in the seat (lol too much exageration)

torque = high @ low rpm's (~110lb/feet max)
hp = high @ high rpm's (~120hp max)

[thegreatdane]

Check if your secondary butterflies closes/opens.

[smufguy]

dont expect this car to make you feel the power and torque at higher rpms by just having a stock exhaust. I know a lot of guys can vouch for it but with a DC header and a full 2.25" exhaust you will feel the torque and power build up from 3K all the way to the redline. I know carotman said it too and i have experienced it, the power is still there till the redline. It pulls hard.

TheSummoner101: you got your numbers all wrong dude. Lol lb/feet what is that units? def not torque (torque = Force * Distance [hence lbs*ft] )

for a 88-89 efi: 120hp @5800; 122ftlbs @ 4000:

[Nice Guy Neil]

What are those secondary butterflies / throttle plates you all mentioned?

And thanks for the replies folks.

[accordlxi2.0]

okay.. 88-89 efi came with secondary throttle plates...in other word's it's poor mans vtec,lol.
what happen's is when you pass 3,000 rpms, the ecu opens a vac. solenoid and that opens the secondaries you should feel a somewhat rush of power.

in your case you "feel" the power drag after 3grand...so what's going on is the ecu or the solenoid is'nt opening up the secondaries.

[Nice Guy Neil]

I've only got the service manual for the 86 accord, and I can't find it in there. Could ya give me an idea of how to check whether that's working, or a place where I could find that out? I didn't see that in the 88 accord supplement off pauldesign.ru either.
Of course, it could just be that the car is slow. :)

[accordlxi2.0]

well if fully tuned....
well back then (in 88-89) efi 0-60 is 10 seconds....
which is'nt bad.

just follow the vacuum that's attached to the diaphram,. which leads out of a connector, to a rubber vac. line, then a metal vac. line, then a rubber line again into the mysterious "black box".
then open the top to find the solenoid to it.

[HondaBoy]

so y'all are saying a vacuum solenoid thing is opened up at a certain rpm right? if so maybe the vacuum line is busted or something. being the car is old, that would be possible. i'd check lines just anyway. so 0-60 is in 10 seconds? my old carbed engine with auto is lower 9 second. 9.3 second when it was all stock stuff.

[accordlxi2.0]

hold up....
you had a carb 2.0 dx/lx 0-60 is 9.3!

i could've sworn that it was 13 seconds....

plus if it was a vacuum leak the car would'nt run right.
the vacuum holds the plates closed till it reaches 3,000rpms.
or it could the spring not opening the plates....

[HondaBoy]

i thought that time was about average for it. i dunno, i should see what my time is with my new ignition parts and exhaust. it's around 13 seconds when i have people in my car though. lucky for y'all with fi engines, there's not so many vac lines as the carb. i'm gonna fix that problem soon though.