droob

Hi Guys

I've done a lot of searching and read lots of posts that seem relevent to the symptos I'm getting. That said I thought I would post my whole story here and see if anyone could help me narrow down what the issue could be.

THE CAR:
- 2004 MT (56,000 km)
- Recently added a CAI
- Everything else is stock

THE ISSUE:

- Car idles a little rough.

- When drop the clutch in the RPM fall in a non-smooth manner and will overshoot and fall too low

- THe above problem gets worse when rolling up to a stop sign and breaking in neutral (it has even died, but can be started again right away)

THE BACKGROUND:

I recently had installed an aftermarket intake. I tested it out and everything ran fine, though the car was idling slightly lower than before (800 instead of 950ish). I drove around normally and aggressivly for 100KM no problems. I parked and came back latter and started the car, then reved it a bit and it threw a CEL. I did a reset (via the battery disconnect method) and cleared the CEL.

Since the battery disconnect I've had issues. The idle is now rough and doesn't sit it fluctates +\- 50 RPM. When I rev the engine in neutral and let it fall the rpm fall isn't smooth and falls below idle and pops back up, hunting for idle.

I thought the issue was the by clearing the ECM it lost some of it's learned parameters so I figured I need to drive around a bit. I drove around the block a few times and found as I costed up to stop signs and braked the RPM dropped quickly and even lower. Eventually it died. I was able to start it again and drive home. (It did die again in the parking garage).

I turned the car off and turned it back on and it idled rough and the behaviour was same as it's been since the reset.

Note: the engine temperature seemed normal but to be honest I didn't pay too close attention to it. And I currently have no CEL or any other warning lights.

WHAT I HAVE READ

- Could be a Vacume Leak (How do I find it?)

- Could be some nasty oil build at the Throttle Body (though I didn't see any when I installed the intake and it's only been driven 200Km since then)

- Fouled plugs\Bad Coils

- Something with the MAF plug maybe???

Any ideas? Any help would be greatly appreciated

Jon316G

iTrader: (1)

Sounds about right... but I would start in reverse order.
What brand of aftermarket intake do you have?

swoope

iTrader: (5)

well,

as you are talking km. where are you?

and just an idea.. you might search for ac amp..

it will need to be an advanced search with posts from the beginning..

it is an odd 04 thing.

if you cant find it let me know..

beers

Flashwing

My experiences with my car dying at a stop are usually the PCM leaning out the fuel mixture enough that the RPMs fall and it stalls.

If the last thing you changed was adding a cold air intake, here are some things I would check.

First, ensure that you have the proper screens installed in your cold air intake. If you have no screens then the MAF is not seeing proper airflow. You can make them out of screen material used for patio doors if necessary.

I would suggest using two screens, but one is required prior to the MAF.

The Mass Airflow Sensor can get dirty from time to time. I would remove it and use some electrical contact cleaner on the MAF.

Should none of that solve your problem, you may move onto other items such as spark plug replacements, checking your coils etc.

Common vaccum leaks with an intake would be the vaccum hoses that attach to the intake itself. Otherwise follow up with what swoope suggested since my experience has been with an 05.

swoope

iTrader: (5)

i guess i have to follow up..

with the 04 if you reset the ecu you have to reset the ac amp.. it messes up the idle.

but if the car is stalling after several drive cycles..

this is the order.

plugs good?
plugs tight?
wires good?
wires tight?
coils good?
vacuum leak?
fuel pump good?

order of importance and what really happens. price depended...

beers

04RX8man

^if all of swoope's look good then i would recommend trying to put the stock intake on and see what it does.......make sure all vacuum lines are on and not leaking...if you still have the problem it's time to get a compression test u may become a part of the new engine club

zoom44

vacuum or maf or neutral sensor on tranny

droob

Thanks for all the input

I'm going down to check the basics.

Unfortunatly I can't find the right reference to the ac amp reset thing. So I won't be able to do that.

Jon316G

iTrader: (1)

1. Make sure key is in the OFF position
2. Press and hold the front defrost & air intake selector buttons simultaneously
3. Turn the key to the ACC position for 3 sec (while still holding the two buttons)
4. Turn the key to the ON position for 3 sec (again, while still holding the two buttons)
5. The rear defrost indicator light will flash 3 times if done successfully

droob

Allright I just got back from messing around.


What I did
- Checked all the vacuum line connection everything looked good
- Took off the intake took a look and put it all back together
- Ran it, and drove around a bit

What I noticed
-Throttle body and intake tubing was spotless clean
-Hose clamps seemed a little loose ( I made sure it was nice and tight)

Results
-Better idle
-RPMs didn't drop as low
-It didnt' die

-But it isn't perfect.
-RPMs still fall in an un-smooth manner
-Breaking from speed (40km+) does cause the rpm to fall a bit below idle
-When idling the odd time the RPM will jump to 1000 then fall

Anyways, I'm going to drive more tomorrow and see how things go. Probably tryand dig up some screen.

Thanks again

swoope

iTrader: (5)

i would pull the room fuse as it will reset the ecu.. it will take several drive cycles to settle down after that.

you likely have built fuel trims with a vacuum leak..

also if the idle hunts/ goes up and down. if you push in the clutch and it goes away. you have a bad neutral position switch.

beers

droob

Everything is running smooth again. I just need to drive some more and let the computer re-learn.

Thanks for all the help