hondaS2001

well mine used to exhibit slugishness at partial throttle no matter what I did, and on my friends too, I just chalked it up to being a characteristic of that motor/car. However, I never had problems with it lagging during WOT. A slight knock sound to you could be ticking/tapping from the valve-train to others so dont discount that yet. I doubt you have issues with your timing belt auto tensioner so early, but if you want to test it, go on an incline and take off at about 2500 rpms, and when you release the clutch and the rpms fall, you should hear it the most. When the tensioner gets really bad you will be able to hear it while revving by hand inside the engine bay. If the knocking sound was more serious it would most likely get louder/faster when throttle is applied, if it is a loose valve the noise dissapears with throttle because it not only gets drowned out, but also more oil is circulated through the head. It was also noted that a couple people with 5th gens had problems with faulty/loose ignition wires causing the same type of problem you have been having.

hondaS2001

also, an exhaust leak would that could cause such power loss would most likely be really noticeable, it may be causing the sound you are describing, but when you give it throttle you should be able to hear it increasing or getting faster.

Road Rage

the noise sounds like an idler going bad. the noise should be the easiest part of your mess to fix because it is calling attention to itself yelling "Fix me, I 'm here!".

yes, the car could have a clogged fuel filter in 18K miles from a dirty station tank, esp if they let it run down to beat a price hike or to switchover to spring blends; however, I do not think that the switchover fuels would cause dramatic driveability changes such as you are describing.

I still say spark, fuel.

A good shop tech should be able to use the tools of the trade to check all this
1) adequate fuel delivery (pulse width/duration) that would identify adequate fuel - did they check fuel pressure? You could have a weak, intermittent, or about to fail fuel pump.
2) adequate spark (proper advance timing, adequate spark output and shape)
3) Since this is an OBDII car, I am really surprised that you are not seeing a code - i checked again to see if you were the original owner, cause i thought perhaps an unscrupulous seller had disabled or disconnected the MIL. But since you are the original owner, I have to believe you are not masochistic.
Does your MILlight when the key is on, but the car not cranking? That's Malfunction Indicator Light, part of the OBDII system. Did they check DTC's(diag trouble codes)?
4) Try a strong cleaner like Techron or Regane to ensure that deposits are not the culprit

I would check the:

the EGR - again - not just a static test, as this is an active device in late model cars (that is, EGR is disconnected during open loop and at WOT)
the MAP sensor
fuel pressure regulator
Throttle position sensor (if defective or out of adjustment, it will mess up driveability)
EVAP - could be purging at wrong time or leaking
All vacuum attachments and fittings
injector performance (width and duration of fuel delivery)
compression on all cylinders
spark plugs
does this unit have a coil? (spark igniter or whatever the Japanese call these things)


What has me concerned is that if the car were running consistently bad, it should have set a DTC - yet you say the dealer checked and found none.

I would find the best Honda tech you can and let him or her ferret it out. It might not be a Honda dealer, but a Honda specialty shop.
I think a sensor is getting spotty, but your car may run just well enough that a hard DTC does not get set.

hondaS2001

The h22's have a distributor, but you cannot advance/retard timing manually on it like other cars, it is controlled by the ECU. I have heard of some people having problems (like road rage said to check) with the throttle position sensor, but I believe the dealer only will sell it with the whole throttle body. Also, the sound you are hearing could be a part of the problem but doesnt necessarily mean it is.

KCLude01

Thank you guys so much for all the help! This is one of the best boards out there, and I have been to a TON! I have to be honest, I have received more replies from you guys then any Prelude specific forum. That is a testiment to the kind of people on this board. I have lurked this board a long time and I am glad I joined. I will definitely stick around after my problem is resolved. Who knows, I might even be an owner one day. I was looking at a new MY04 Silverstone S at my local dealer a couple months ago. I have to say you guys have a beautiful car. I still love my lude though, so I am going to hold on to her as long as possible. Anyway, to the issue at hand. The car has been driving MUCH better lately. I don't know if it is the spring/summer fuel blend or not, but my car started this issue last August. When do they go to the winter blend, and could that cause this much difference? I checked the plugs many months ago and they looked normal to my Dad and I.

Road Rage - you bring up an interesting point about the EVAP. I had noticed one day when I got home something was making a noise every 5 minutes or so. I was washing my car at the time so that is why I heard it. Also, that same noise happens when I get into my car first thing in the morning sometimes. Is it the same sound I am hearing? It sounds the same. Is it a sign that the EVAP is going out, or is that normal? The dealer checked fuel pressure, oil pressure, valve spec, and compression in October. I don't know if they checked spark. They said they all checked out good. I don't know if I really trust them 100% though. I did give the MAP a good wack or two and reset the ECU. Not much change though. That has been awhile though. The car does have a coil. Is the ignitor the same thing as a coil? I tried a couple fuel injector cleaners, the Krex from honda and something called gas kicker. They both seemed to help while they were in. The Krex was used in November or so, and the gas kicker late last month. What is an idler? I have never heard of it. I will also see if the MIL lights when the key is on.

hondaS2001 - I listened to my car outside of the garage today, and I think I was just being paranoid with the knock noise. I couldn't really hear it outside of the garage, so I don't think it is a concern. What did your lude normally idle at? Mine is always at 500 unless I turn the headlights on. After the headlights go on it is at 750.

hondaS2001

First off, the lude is no slouch, as much as I love the S2K, I STILL miss the prelude :-( Mine idled kind of low like yours, and I never really figured out if the first little bar on the tach represented 500 or it represented 0-200, if you know what I am talking about. Also, what weight oil are you using? I tried 20-50 for a while and it seemed to not run as well as when using 10w-30. You might try changing out the ignitor too but if I remember correctly they are more than a few bucks. Just keep going with the cheapest/easiest stuff to eliminate possibilities, im sure youll get to it one way or another, start with the cheapest/easiest stuff that way if it works you didnt waste a whole lot of time/money. I doubt you would have a dirty throttle body/intake manifold but do you think it would be worth a shot to spray some throttle cleaner in there? It may start up rough after you do that but once it gets burned off it should go back to normal if not improve the situation.

hondaS2001

also, like I said, mine felt sluggish and had an intermittent power loss at partial throttle in the 3-4k rpm range, even AFTER i replaced all those things.....WOT then it wouldnt exhibit it as much.

s2000guy

Sounds to me as if you have bad gas in your car. It sounds like it is picking up water at times. Where do you normally buy gas? Another possibility is a bad ignition coil. That can cause a misfire on acceleration. Are the spark plug wires original or did you replace them with aftermarket wires?

KCLude01

It seems like my car is running better lately. Could the difference between winter and summer fuel blends make a difference? When does the spring/summer fuel blend start?

hondaS2001

BTW, when you guys checked the plugs did you happen to check the gap for good measure? I know its probably an unlikely source of the problem but if they were WAY off I could see it affecting performance.