VTC_CiViC

Ok, for the past 2-3 weeks now something has slowly but surley been growing in my car, and it's not mold! I've been noticing that my car has been having major idling issues along with very hard starts as of late, and I can't for the life of me figure out why. Perhaps a few of you here have experiences similar issues, so I'll cough up each of the problems i'm experienceing now and let you form your own opinion..

Issue #1- Funky Idle.

While driving along my merry way, I'll remove the car from it's drive gear and place it in neutral, only to feel the car shudder as it does when the rpms get too low, my battery light flickers, my AVCR shows as little as 350rpm and the I see the tach dancing just above '0' as the ECU struggles to idle the car. This happens for a few second each time I let off the throttle and go into neutral after driving, and it's been happening for weeks now. Quite simply, it's as if the ECU canot 'catch' the rpm when the come down to idle, rather than leveling off at 600rpm where it should idle, it drops to the low 400's and the car just barley idles for a few seconds, sputtering and coughing till the ECU finally fights it off and idles normal till the next time I start driving.

Issue #2- Low throttle 'popping' and hesitation.

At very low throttle positions (5-7% according to the AVCR), as the car slowly descends the tach I get alot of 'popping' comming out of the exaust, very rappidly, not very loud but more than audible enough to hear it inside the car. Sounds alot like somebody making popcorn. Also, if I give it just a bit more throttle (enough so that I hold speed rather than slowly decend) rather than just smoothly holding speed, it feels as if the car just randomly hesitates, jerking my head forward slightly as it happens over and over. Only way to stop it is to let off the throttle altogether, or increase the throttle.

Issue #3- Hard starting.

Seems like the car has 3 random choices every morning when I start it. A- Start 100% normal, B- start and idle at 1500rpm for a few seconds before turning normal, or C- start and idle at like 300rpm and diesel for a few seconds before slowly turning normal. Sometimes, the damn thing doesn't even want to start at all, I can literally spend 5+ mins turning the car over and over and over before it will sputter and slowly idle up to normal pace. I've found the only way to bypass this painful procedure, is to hold the throttle wide open when cranking and the car will start up much sooner, albeit still idle funky at first.

I know it's alot and I don't expect everybody to answer everything, but know this... when I first left SFP after the Hondata install/tune back on 5/5/02, the car was absolutley wonderful. Idled like stock, drive like stock, started like stock, it's been over the past 3 weeks that it's turned into nothing short of a pain to deal with. I actually dred drving my car now because I hate the sentation of the car sputtering so much, I can feel my whole body shake everytime I go to neutral after a drive not to mention the lovley battery light screaming at me to raise the revs while I sit helplessley and watch. I belive the car is running excessivley rich, and I'm proabably due for a plug change (been maybe 10k miles), but I've never encountered anything like this before. I wonder if this has anything to do with my random CEL for the O2 sensor? Well anyways, I hope somebody out there profecient with Hondata has an idea or can shed some light, because I'm growing ever more unpleased with my car every day and selling it is becoming more and more of an option..

HXMan

Definitly replace the plugs. That could be a big reason right there.

C-speed

Well.. at first glance, i suspected that the Hondata was seriously out of tune. But I guess you did have it tuned and that it ran perfectly until onlyrecently.

In that, cause i suspect 2 things, either a temperature change in your area has cause the maps to require a slight retune, or its a hardware issue - like your plugs or wires are bad.

BoOsTeD_eK

would the alternator be messing stuff up? Or maybe you should switch to colder plugs.

CovertFI

i would also check the plugs. but to me it sounds like fuel starvation

bruthaboost

I have #3 as well, but I'm seriously untuned. Changed the spark plugs and no diff. **** luck with what you find and IM me if you find the solution to your probs. #3 really is a pain. I've sat 5-10 mins at a gas station trying to get started

dustin

What fuel system do you have other than the Hondata?

VTC_CiViC

440cc injectors, walbro 255lph pump, NGK BCPR7E-11's

VTC_CiViC

EHh I duno about starvation, I get a very strong odor of fuel when I park or when I have the hard start issue, so I'm thinking it's too much fuel if anything. Has anybody had an issue where Hondata needed readjustment after a climate change? I mean it hasn't been anything drastic, but over the past few weeks, it's been raining alot and it's gotten far more humid latley whereas before it hadn't rained in months and was very hot and dry..

Mr. Softee

faulty o2 sensor?

dustin

No -- Did your factory ecu ever need readjustment when your car was stock? The same temperature and barometric correction systems still exist with Hondata.

I'd look elsewhere -- there is something wrong with the car. I would check the fuel and ignition systems.

Dustin

Spade

You might want to try just removing the IACV out of the picture........see if that helps....

TurboSedan

I have #1 pretty bad, I have stalled out while in neutral a few times. It idles real low after it warms up to operating temp. I think I will try putting the stock plug wires back on but the NGK's were doing fine before the Hondata went on. Hmm.....

dbman96

You mentioned that you have been getting an O2 sensor CEL... and all the problems you're having pretty much revolve around low-speed closed loop operation, so I would consider swapping in a known good O2 sensor.

trbob16a

Sounds to me like the issue may not be the hondata if it was working fine and now isn't. The stock honda computer will take into account elevation changes for you at part throttle. You could try the stock computer to see if you still have part throttle and start up problems, that would help figure out if it was hondata.

Either way the part throttle will need tuning

VTC_CiViC

Well see Frank told me that when he sets up Hondata, he removes all closed loop operations period. In other words, the car is not paying attention to the sensors, only to what the ECU is programmed for at that particular moment. I know it sounds odd and even I was a little supprised, but then Frank knows his stuff so who am I to question it right? Does anybody esle remove closed loop operation with Hondata?

echo999

Sounds like a faulty IAC valve or the other valve that is open when the engine
is cold.

Do you run a filter? I had a similar problem because I ran no filter for awhile, and
my IAC valve was filled with dirt.. I took it off, shot a bunch of carb cleaner into
it, and ran it.. fixed the problem.

dustin

My car ran smoother with closed loop on w/ hondata.

Do you have your hondata ROM file? I'll give it a look.....

On cold startup the car is going to use cold enrichment anyways. It won't go closed loop until the motor starts getting warm...

X2BOARD

Could it be some type of ignition/ignitor failure due to the high levels of humidity these days ? When last have you changed the cap/rotor ?

VTC_CiViC

Ok well, I just spoke with Frank and let him know what was up and he cleared a couple things up. I told him about the random CEL for the primary O2 and he let me know that Hondata does indeed use it for manifold pressures under 790mb and idling, therefore if that sensor is randomly causing a CEL, it must be that it's headed out the door and this will directly affect the idle, ala what dbman was noting. So that, in conjunction with the plugs which he also mentioned to change, will *hopefully* cure what ailes me.. let's hope it works!

Dutchie

VTC Civic- I am having no #3 also. I also have Walbro 255, RC 440's, but I have the Techtom chip instead of Hondata. My car ran fine for over a year and a half in all different weather. (-30F to 90F). I have noticed that the car starts better in colder weather, and can take a long time when it is hot out. One time I had to give it gas to start too. Also, it deisels worse when it is hot out. I have changed Fuel filter, air filter, cap, rotor, wires, plugs (at different gaps), all to no avail. I even had and MSD Digital 6 + Blaster coil on for awhile.
Is your car easier to start when it has just been running?
I think it is either the igniter or the IACV (I am going to try and clean it). I will e-mail you if I figure it out, could you do the same or post the fix? This is really pissing me off.
Oh yeah, my idle sometimes surges a bit as well, and I was thinking the O2 sensor could be the cause. I also get a code 1 every once in awhile. That doesn't explain the start-up prob though. Do you get a puff of smoke when it is hard to start too?


[Modified by Dutchie, 7:04 PM 6/20/2002]

brcivic411

keep us updated...

<-- wondering why closed loop operation was removed

VTC_CiViC

Need new primary O2 sensor

dustin

get one from http://www.thepartsbin.com

cheapest

VTC_CiViC

Are these quality ones? Just curious cause I think I can get them for about $80 or so from http://www.hondaautomotiveparts.com and theseare factory Denso's.. what do you think?

EDIT: looks like they don't carry O2 sensors anyways


[Modified by VTC_CiViC, 4:36 PM 6/20/2002]