Idling problems after ECU reset

Ok so here's how it goes. I recently cleaned my throttle body with tb cleaner recently and took it for a drive...damned thing was pretty responsive :D Anyway, I decided "what the hey, i'll reset the ecu while i'm at it" So i left it to reset with the negative dc'd for around 2 hours with the bonnet up. It cooled down, and i reconnected the negative terminal. It started fine, warmed up and...wtf?? It starts idling funny. It jumps up and down between 800rpm to 1.5k rpm...and it keeps doing this (i thought it was the ecu adjusting itself, but it just kept going). Sounds kinda like this "VROOOM vrum VROOOM vrum...". It wasn't doing this before reset the ecu, and it didn't do it before I cleaned up the TB either. Although i did get some TB cleaner on the outside of the TB sensor areas (but they're liquid tight right?), it shouldn't affect the idle correct?

I'm outta ideas. It was suggested to me that the dizzy needs to be adjusted but it hadn't been touched at all thus far and it ran perfectly fine.

Any ideas at all??

its saying drive me harder, you drive like a bitch..... really tho man just reset your once more. If it continues take it to a specialist

u shouldnt drive hard at all after "Resetting" an ECU...its hunting and re-mapping ( well , to those words anyway). Just drive EASY for the next 50ks or so. DONT overrev as it could casue damage.

Thanks fellas, i'll give that a shot (the reset) and see how things go afterwards (easy drive for the remap)

reset it when the car is cold.

let it idle until the car gets to operating temp, without any user interfearance.

operating temp is when radiator fan comes on twice.

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Originally Posted by ProECU

operating temp is when radiator fan comes on twice.

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...operating temp. will be reached as said above , but takes some time (10+ mins sometimes) so dont freak out. It gets there and the fan wooshes on so dont fret :)

I've just gone outside to undo the negative terminal. I should leave it like that overnight right? So tomorrow morning it'll be completely cold. I'll start her up, then let her sit till i hear the rad. fan come on twice. After that it should be all cool and ready to drive ey?

Thanks :D

Oh shit, i forgot to ask. Is it ok to start the car with the remote start? Or be it much better to start it normally?

leave it off for about 10 mins ( i have no idea exactly what it takes for the ECU to reset) - then park as usual overnight.

Then as suggested

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reset it when the car is cold.

let it idle until the car gets to operating temp, without any user interfearance.

operating temp is when radiator fan comes on twice.

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Dont u simply remove the "backup" fuse for 10min?
(Rather than removing the neg terminal)

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Originally Posted by EuroDude

Dont u simply remove the "backup" fuse for 10min?
(Rather than removing the neg terminal)

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Isnt removing the backup fuse useless if the normal ECU fuse is still inplace ? Still , either remove the negative terminal fromt he battery for 10 mins or so , or remove the ECU fuses .

10 min , 2 hours. you guys are funny

only takes 30 seconds to reset the ecu

7.5 A back up fues is all you need to remove. 10 seconds will do it.

Sorry, I don't know if you guys saw the edit in my previous post, but is it okay to start the car with remote start? Or is it better to start it normally? Coz the remote start lets the car idle higher before inserting the key.

after you rest the ecu it is very imortant to start the car with the key, turn off all the electrical items, and let the engine idle till it warms up.

car must learn its own idling load of the altenator.

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Originally Posted by ECU-MAN

10 min , 2 hours. you guys are funny
only takes 30 seconds to reset the ecu
7.5 A back up fues is all you need to remove. 10 seconds will do it.

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Yeah thats what I thought - 10 minutes seemed too long. 30sec sounds right.
There is an ECU fuse? I thought the backup fuse was the ECU fuse...


@hayashi, you should start/idle the car normally so u dont confuse the ECU. Next time u start the car it may idle at 100rpm lol

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Originally Posted by EuroDude

There is an ECU fuse? I thought the backup fuse was the ECU fuse...

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yeah the back up fuse is the reset fuse for the ecu,

it also has a few other fuses. but its best to use the backup fuse.

phew! Thanks for clearing that up for me! :D I'll know to remove the backup fuse next time instead of unbolting the negative terminal nut all the time.

Cheerz fellaz! Probz (hopefully) solved :D I'll keep it posted on how it goes.

Ok, so i left it overnight, then turned it on by key...had all the electrics off aside from the handbrake light. It sat there idling stone cold for around 8-10 mins, then it sorta shat itself (it went VROOOM VRUM VROOOOM VRUM etc.) so i said: "Shit maybe i need to drive it around for a bit" so i did, and everytime i stepped on the clutch into neutral it does the same sorta stuff. After a short drive on the freeway and onto blackburn road, it seemed to have gotten better (its now idling at 1.35k rpm, which is still too high) but every so often it'll start shitting itself over and over.

So, i don't know what to do now and am really getting worried that i might've damaged something without knowing it.

If anyone has even a single clue on how to fix it, please tell me! :(

Thanks again guys!

I dont know much about ECU's but thinking logically - the way I see it is that the ECU was compensating for something else that was out of tune, and now since u have reset the ECU, it has gone back to learning mode.

So the ECU may just need time to relearn to compensate.
IMO you should look into what else could be causing it such as:

Dirty IACV
Dirty FITV (If its a D series)
Dirty Fuel or Air filter.
Dirty Fuel injectors.

Or maybe even a Tappet adjustment may help.

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Originally Posted by EuroDude

I dont know much about ECU's but thinking logically - the way I see it is that the ECU was compensating for something else that was out of tune, and now since u have reset the ECU, it has gone back to learning mode.

So the ECU may just need time to relearn to compensate.
IMO you should look into what else could be causing it such as:

Dirty IACV
Dirty FITV (If its a D series)
Dirty Fuel or Air filter.
Dirty Fuel injectors.

Or maybe even a Tappet adjustment may help.

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Ok ok, so i checked all those...now...none of those were dirty...so now i'm convinced its the vtec solenoid. Well its what a mate of mine said when he came over.

The tappet adjustment will come later on.

Whats your take on this fellaz??

Cheerz!

Heres and update on whats happened so far. I recently tried cleaning out the IACV (and the vtec solenoid while I was at it) and it proved no results. So I reset the ECU again...this time, the air con compressor is spewing out air from the two hose connection points on the compressor (although the AC isn't even connected). The ac switch inside the car is off, and the heater isn't even on. So i'm like: "WTF is going on now...". I seriously don't know whats happening guys, the car's just acting like a little bitch now.

Idling is still jumping up and down between 1k and 1.5k. I went to the wreckers to get some answers and they're convinced that the IACV is faulty, resulting in the whack idling pattern. Next Tuesday, I'm gonna pick one up and fit it to see whether they're right or not...otherwise, I might just have to buy a new one or remap and tune the current ECU.

I'm outta ideas...hopefully someone can shed some light on this situation...I'm seriously getting fed up.

Oh I just remembered something. When I use to start the car with the remote start, and I'd put the key in and turn it to ignition, the AC would make a whistling/gurgling noise and would stop straight away after the remote start was disengaged. It makes the same noise continuously non-stop now.

Could it have something to do with the whole remote start system since its linked to my ECU?

Thanks fellaz.

I really really doubt the ECU is at fault. If all else fails, get a pro mech to look into what the cause is.

There is a possiblity that when u cleaned the Throttle Body, some gunk may have flowed into who-knows-where and caused problems.

Maybe you should try re-cleaning it, and spray cleaner in the side pipes within the TB.

What TB cleaner did you use? Some can damage sensors, so you should test the functionality of the TB sensors.

ps. When you short the ECU diagnostics connector, do you get any ECU codes?

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Originally Posted by hayashi_1986

Oh I just remembered something. When I use to start the car with the remote start, and I'd put the key in and turn it to ignition, the AC would make a whistling/gurgling noise and would stop straight away after the remote start was disengaged. It makes the same noise continuously non-stop now.

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whistling/gurgling noise? You mean a high pitched squeel noise?
Maybe the AC belt needs tensioning.
U can do this urself as its not hard to do.

Do u still hear the noise if AC is ON?

Well I'm using the Nulon brand TB cleaner atm. It hasn't damaged any sensors and the car hasn't been throwing CEL's. I'm not sure if it'll happen if I use the ECU test method through the plug lead under the passenger dash, since nothing is showing up on the dash when driving.

I've tried replacing the map sensor with no luck.

I'll keep trying to see what happens.

Thanks

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Originally Posted by EuroDude

whistling/gurgling noise? You mean a high pitched squeel noise?
Maybe the AC belt needs tensioning.
U can do this urself as its not hard to do.

Do u still hear the noise if AC is ON?

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Its not a high pitched squeeling, other it would've been the belt. But the belts fine. It's actually coming from the two small holes where the AC pipes go. It's blowing air out from the two holes and making a seriously f'd up noise.

Like i said, it use to make this noise when i turned the key after i use the remote start, but only for a brief moment and it would stop.

Your engine is a D16Y yeah?

My idle was foobar'd as well, after screwing in the FITV knob the idle went back to normal.

U have screwed the FITV knob all the way back in right?

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Originally Posted by EuroDude

Your engine is a D16Y yeah?

My idle was foobar'd as well, after screwing in the FITV knob the idle went back to normal.

U have screwed the FITV knob all the way back in right?

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So how do I go about doing this? I did a search already and can't find any pics or pointers on how to do it.

FITV is in blue:
http://img380.imageshack.us/img380/3387/throt19ck.jpg

More info here:
http://www.emotors.ca/Articles/97.aspx

Thanks a heap, i'll give it a shot later today :D

yeh no worries. There are just three 10mm/12mm bolts underneath the FITV module and it drops of the throttle body. Screw the white FITV knob thing all the way in and re-assemble. make sure the black rubber seals are in place. (mine were tricky to put back into the grooves)

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Originally Posted by hayashi_1986

Well I'm using the Nulon brand TB cleaner atm. It hasn't damaged any sensors and the car hasn't been throwing CEL's.

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that aussie brand TB cleaner should be fine, i use that on my car and my friends too, no probs at all.

goodluck with the problem.

OK, heres the update. I've pretty much cleaned up everything possible from the IACV to the FITV...even the damned VTec solenoid lol. Then I did as eurodude advised and did the ECU self diagnostic. Bloody thing came up with a MAP sensor error.

If I put a new MAP sensor in, do i have to reset the error in the ecu??

If thats the case then I went to honda wreck for nothing the other day...coz I simply attatched a new one to test and didn't bother resetting the ecu. It failed as usual with the revs still jumping up and down.

Whats the go on this? Reset or not reset?

you have to reset the ECU to clear the code. Do it and then get back to us.

Here's an update. The ECU was completely foobard. Replaced it and is an smooth as silk. No problems now cept for it throwing a code 14 (IACV) but that can be fixed quite easily :D Thanks for listening to my seemlessly never ending story!

Cheerz!

CASE CLOSED!!!

awsome

so is this thread :)