BREADFAN

So I have a '98 hatchback, 1.6 NON Vtec, it has a butt load of miles but it also has , new head, new injectors, new fuel pump, header, no cat, ALL new sensors, new timing belt, basically all new except bottom end. Under
hard acceleration it starts losing power about 3500 rpm, it never gets to 4500-5000, under normal driving (any gear) it runs like a million bucks, but if you floor it it just loses power. I run 93 pure gas, no ethonal, NGK plugs, ACCEL distributor. It doesn't use oil, no smoke at all, has very high compression for as many miles as it has (198,198,197,198). I'm kind of lost, any suggestions?

xRiCeBoYx

iTrader: (22)

any check engine light?

also, why 93 octane? You don't need it unless you're running forced induction or high compression.

ezone

If you GENTLY accelerate, can you reach redline?
It only has a problem when you floor it?
No restrictions in the intake system? (mouse food stored in the resonance chamber)




Compression test numbers look average to me, I expect to see that range when I check.
Got any fault codes?


You got an Accel distributor---- why?
Aftermarket distributors are crap. Recent thread link: https://www.civicforums.com/forums/2...1381-code.html

Did this problem begin immediately after the distributor was installed? Got a good original dist you can try?
Pull the dist cap, check the wiring to the igniter, maybe someone didn't get a spade terminal correctly installed or a female spade connector doesn't grip tight enough (both were common and there's a bulletin about loose spade terminals causing ignition problems and cat codes).


Burn LOW octane gas.


Still no joy? Got a scanner that can display live operating data? See if the front O2 sensor stays near 0.90v during the hard acceleration/poor running. If its voltage drops to near zero that's a sign it's starving for fuel........
Put a fuel pressure gauge on it, tape it to the windshield if necessary (I do this).....then monitor fuel pressure while driving....see if pressure drops as the engine loses power. Check fuel filter if it does.

BREADFAN

No codes, it doesn't matter at all how I get to the floor it will only pull till about 3500, it has a cold air intake, it's clean that was the first thing I checked. I put the Accel in it after a friend put his civic in a wall at the race track, I pulled a 100% new stock distributor and put this fairly new one in.It did the same with both dist. nothing changed at all. The valves clatter with low octane gas, timing is dead on, it's been checked and rechecked. I work at a Kia dealership, I got our fuel pressure gauge and taped it to the windshield and drove it over night looking for drops or spikes, it remained steady, it rose when it should, dropped when it should. That's why I'm so lost, the numbers say it should be right, but it's just a dog.

BREADFAN

I seriously do appreciate you guys responding!

mcnoople

Is this problem new? You mention it got a head, is the problem more recent than the head? I only ask because the TPS and MAP electrical connections on some of our cars can be plugged into the wrong sockets and get swapped from time to time. It causes some weird issues when it happens and doesn't cause a CEL.

Connector interchange bites honda in the butt from time to time.

Wankenstein

Check mechanical timing...may have jumped a tooth?
CEL's?
Cylinder misfires?

ezone

If you baby the gas pedal will it go above 3500? Will it go to redline?


Can you make it (bog) happen while sitting still in the driveway?
Spritz some flammable carb and throttle cleaner into the throttle body while throttle is wide open and bogging, see if adding that extra fuel makes it run better. At least this would tell you if it's starving for fuel or not.

Valves can't be affected by octane. Hondas valves are all mechanical and valve lash must be adjusted periodically. Are valve clearances correct?

If you get spark rattle then you probably have something else wrong....like cam timing or something...or maybe EGR is missing at part throttle? IDK but I'll keep that in mind.

Stock original cam ---or did the cam come with the head?


Did this problem exist before the head was replaced?

BREADFAN

Well I did second guess myself so I got our master tech to verify the timing and it was spot on. The car has always been like this, I had the opportunity to buy this complete reman head dirt cheap so I went ahead and did it only because the car sat for about a year and I put new gaskets (all gaskets head,intake, oil pan) on it. It has always kind of bogged at about 3500 rpm. I pulled the gas tank had it cleaned, put a new Honda pump in it,new filter. It shows no misfires, in fact, the car runs perfectly it idles smooth as silk has no blow-by, spark plugs burn a nice tan color, header has very little **** in it, ice cold a/c, 80lbs of oil pressure, it just falls on its face at and after 3500 rpm.

BREADFAN

Oh and no it never gets to red line.

ezone

So are you saying it had this problem before you replaced the cylinder head?

BREADFAN

Yeah the problem has been there since I got it. My father-in-law gave it to me, he bought it new 98, he had Tameron Honda do all the service work on it.

ezone

....

BREADFAN

I'm so lost on this car, everything says it should run pretty good, and it does until 3500.

xRiCeBoYx

iTrader: (22)

I'm still stuck on that "valve clatter with low octane" thing. Definitely not normal, considering it's a stock motor. Something is screaming detonation to me. Problems may be interrelated perhaps?

BREADFAN

I'm with ya. That's kind of the reason I second guessed myself on the timing. The clatter in itself is weird because when they start the noise you can just floor the pedal and it stops. It's almost like a bad EGR, except it doesn't have one. I put a new PCV valve in a few days ago, nothing really changed. I drive this thing alot, I regularly drive it 250 miles round trip on football saturdays, I drive to work everyday, and usually around town. It runs smooth and quiet, no vibrations, no smoke, nothing just no power if you need to be in the throttle, it makes life hard on big long hills or pulling out into traffic.

BREADFAN

Thanks for taking the time out to reply.