**sigh sorry for the long post.. anyways.. I like my prelude.. but it has been quite a headache since day 1 .. Engine blew while my dad owned it .. had a new one put in.. since then over a year I've had to replace the clutch, new main relay, distributor, radiator, in addition to me putting megan header, intake, 2.5 exhaust.. After all those headaches the car runs 'ok' ... my main problems are the loss of power in what seems like 1st and 2nd gear.. once I get past them it seems like I can fly.. right after I had my exhaust done it sounded perfect.. not too loud.. but loud enough.. and if I revved past 4000 rpms it would scream.. and now about 6 months later.. the exhaust is extremely weak sounding.. borderline ricey.. not deep like it used to be.. and when I rev anywhere near 4000 rpm it goes completely silent .. errrm along with that.. at stoplights It idles around 800 but theres slight shaking and sputtering like it's going to die... my exhaust tip also seems to have gotten quite black fairly quickly.. which i guess means I'm running rich? I have no idea.. I'm not that car savvy... I just wish my car was fun to drive again... oil was changed 3000 miles ago.. synthetic.. premium gas always.. jdm h23 .. maybe 60k on the engine? 115k on the rest of the car.. ANY suggestions as to how i can make my car fun again ..i.e. exhaust tone back to normal..and power back to normal.. would help!! thanks!!

 

nice motor, i gotta jdm h23 as well. i would start with the usual suspect, plugs, plugwires, coil, etc etc. if that isnt it, check your dizzy. Mine did the same thing at redlights and it was much later my dizzy went out. and yes your exhaust is black because your car is running rich. Nothing really to worry about as they tend to run just a little rich anyhow. When the back of your car starts turnin black from exaust, then you have reason for concern.

 

my dizzy already went out about 3 months ago and I got it fixed..so I should be ok there.

 

sounds like a ignition to me. Check your plug wires very closely, as it doesnt take much of a cut in the wire to cause it to arc. Make sure all plug wires are secure on the plugs, dizzy, and coil. Pull each plug while the engine is running and listen for differences in idle... if you dont notice any difference when you pull a plug wire, that may be your dead cylinder. Also, arc the plug wire to the motor and look for a good spark.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4WSi_guy &raquo;</TD></TR><TR><TD CLASS="quote">sounds like a ignition to me. Check your plug wires very closely, as it doesnt take much of a cut in the wire to cause it to arc. Make sure all plug wires are secure on the plugs, dizzy, and coil. Pull each plug while the engine is running and listen for differences in idle... if you dont notice any difference when you pull a plug wire, that may be your dead cylinder. Also, arc the plug wire to the motor and look for a good spark.</TD></TR></TABLE>

ok.. is what your describing in regards to just the rough idle? or everything else also.. thanks for your reply

 

prolly both, when you replaced the dizzy did you get oem equipment or cheapo stuff? It could be the dizzy again and to find out check your spark... if it is, it should be still under warranty. good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by booyah00 &raquo;</TD></TR><TR><TD CLASS="quote">

ok.. is what your describing in regards to just the rough idle? or everything else also.. thanks for your reply</TD></TR></TABLE>

I think its probably the root of your problems. Exhaust tone change, rough idle, car smells/runs rich...those are all signs of unburnt fuel in the cylinder. Also, ignition problems usually present themselve under a load, which may explain your lack of power in lower gears.

Another thing you can do, its kinda weird...but, you can check your wires in the dark...the school of thought is that you are more likely to see an arc in the plug wire.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by teambk8 &raquo;</TD></TR><TR><TD CLASS="quote">prolly both, when you replaced the dizzy did you get oem equipment or cheapo stuff? It could be the dizzy again and to find out check your spark... if it is, it should be still under warranty. good luck</TD></TR></TABLE>

The shop I took it to came highly recommended from guys I know .. they specialize in only japanese auto care.. so I imagine they used oem .. they've also warned me in the past if I were to bring in any parts for them to install (like my clutch) that they weren't the cheapo kind.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4WSi_guy &raquo;</TD></TR><TR><TD CLASS="quote">sounds like a ignition to me. Check your plug wires very closely, as it doesnt take much of a cut in the wire to cause it to arc. Make sure all plug wires are secure on the plugs, dizzy, and coil. Pull each plug while the engine is running and listen for differences in idle... if you dont notice any difference when you pull a plug wire, that may be your dead cylinder. Also, arc the plug wire to the motor and look for a good spark.</TD></TR></TABLE>

alright so I pulled each plug one at a time and every one of them caused the idle to bog down quite a bit..and each one had what seemed like a good arc.. the last plug i pulled on the bottom killed the car and shocked the *bleep* out of me ... lolz.. gotta start somewhere I guess.. I've looked over the spark plug wires and they all seem ok.. It was about a year ago that I replaced the oem wires with ngk wires..

 

 

bump plzz

 

what kind of plugs do you have in the motor? And how do they look? really black, brownish, wet or anything like that??

 

sounds like bad timing...

 

Yup, I had a similair issue, tha car started running worse progressively, then all the sudden would not run. I replaced damn near the whole ignition, and tryed 2 more full ignition setups. I ended up pulling valve cover and found one of my cams was off by like 3 teeth!!! Luckily my compression still checks out good, and with it fixed the car runs like a champ!

Oh my other guess might be a plugged Catalytic converter, which wasn't my issue since I run a test pipe most of the time.