b18bye

Hey everyone.

Just picked a 2004 Si with the HFP kit. 75K miles, STOCK besides a K&N drop in filter.

My issues are mainly in 1st and 2nd gear. While accelerating between 2,000 and 3,000 rpms it will bog/hesitate, it feels like just stops making power for a second. No check engine lights, oil was just changed, spark plugs look newer (ngk iridiums). I ordered a new IAT sensor as the one in my intake tube looks bent, somehow. My next plans are to clean the IACV.

I will be using my ultraguage to check tps percentages..

* The car is the same with a full tank of gas or with a 1/4*

Any one have any input? This is so annoying to drive, my rsx was never like this..

Helps!

Thank you

Updates:
*** The car seems to use extremely fast, 60 miles per first 1/4***
* The car is the same with a full tank of gas or with a 1/4*
*Once warmed up, if rpms are held at 1500 or 2000 it misfires, sounds like a slow 2-step.. Thinking its ignition.

9/13- Cleaned IACV and adjusted the tps which is within perfect range... No difference..

Any help out there?

b18bye

TPS seems to act normal, but this is testing with an Ultragauge (same as scangauge) I will use my multimeter tomorrow.

Type-Spaz

if you're in neutral and hold the revs you can hear it missfire at that RPM?

b18bye

Yes I can. But only sometimes. Neutral, rev to 1500 or 2000 and hold and there is usually a misfire.

*Also, sometimes the car idles high..

Clean the iacv?

b18bye

Updated!

b18bye

Update with more info, someone has to have some input.

G0tSchnitzel?

Wow i thought i was crazy but looks like im not the only one with this same problem. I get the same thing when i accelrate in 2nd gear right around 3k rpms. its almost like it sputters for a second nd then picks back up again.. It happens very inconsistently for me.

Im also having the same trouble with my gas. Once it goes under half a tank it seems to just evaporate lol

I've also done all the maintance. Spark plugs, oil, new o2 sensor etc.

b18bye

I changed the IAT today because the one in there was bent lol. Drives a tad better, now idles like crap. This is annoying!

ehrkeith

I have the same type of problem when cruising around 3k it bogs for a second and hesistates. Tried all different gas stations thinking I got a bad batch of gas. I know my TPS is good it was just replaced and no other CELs. Only does it once the car warms up.

Its annoying I'm in for an answer also

b18bye

Any thoughts on the Coolant Temp Sensor?

sprody1119

I am also having the same problem, car now has 163k and haven't replaced anything yet , just thought it was how the car drove with the "ivtec" , any thing I could start by doin to maybe fix the problem?

jettadreams

I doubt this would be the cause if the coolant sensor was bad enough to cause any kind of issue it would almost deff trip a code. Seeing as how you have checked so much already there are only a few places left I would look. It could be one of your coil packs is going bad. When they get hot sometimes they can supply a less than normal voltage if there shorting to something in the head, or just not storing the proper amount of firing voltage. Also sounds like it could be a sticking fuel injector or fuel pressure regulator issue. If the pressure in the rail is not strong enough under hard load you could get a loss of power feel. Goes the same for an injector but now that I think about it an injector issue would almost deff trip a miss-fire code. Hopefully you can get it figured out.

RED_90TEG

lol this is funny as **** becuse i usto own a 2002 civic si .. and from 1st to 2nd it usto misfire and since i had no cat and no resonator it would back fire from the exhaust ... we never could figure out what it was... and i sold it... but i had the same issue with my car.. miss fire hesitation and backfiring !!!

tegonfire

the flat dead spot betwee n2k and 3 k rpm THE ******* PRIMARY 02 SENSOR TROWING NO CEL CODE

A REAL MOTHER ****** CHANGE IT EVERY ONE WHO EXPERIMENCE A DEAD FLAT SPOT BETWEE N 2K AND 3K RPM


the ****** primary 02

shaunh84

any outcome on this having the same problem