Rough Idle

[JBMark33]

So, recently I have had a rough idle every so often. Do you think it has anything to do with the P0440 code I keep pulling every other day? I am recharging my K&N right now, and I just replaced the plugs less than 3,000 miles ago since i had UIM issues and hydrolocked the engine twice

Any ideas?

[JBMark33]

Update:

So one of my vacuum elbows that comes right off the brake booster (near the UIM) had a pretty large crack in it, so I replaced it with a short piece of tubing and cleared the check engine light.

Well, since my car has been still idling rough, I keep checking for codes on the code reader.. i even do it while driving.
I have noticed two things. 1.) My car kept setting the code P0410 (secondary air injection system code and 2.) P0100 (mass air flow sensor circuit malfunction.

I got P0410 before, when I forgot to plug my secondary air injection pump in before.

For the P0100... this may be why I am having some other issues too. If my MAF sensor is bad, this might explain a rough idle, sometimes having issues with hard shifting (my mechanic said that the tranny shifts according to the load on the engine, which is helped to determine by the MAF), and also why the steering is tough at idle.. if I am turning into a parking spot that puts increased load on the engine and if the MAF is reading correctly, then the engine can not raise the idle to run the power steering pump well enough.

That being said... I can sort out the air pump issue, but I was wondering if anyone had a spare MAF that I could troubleshoot with, considering RockAuto has them ranging from $135 - $220. Pretty Please? If I had the money, I would definitely just buy one, but I am in college, and I am still working on paying this semester off.

Edit: I tried starting the car each with the MAF plugged in and unplugged and the car ran the same.
In this thread: http://www.pontiacbonnevilleclub.com/fo ... AF#p122437 it is stated that the car should not run correctly when the MAF is unplugged. Ideas?

[JBMark33]

Put a used MAF in the car, and it runs MUCH better. Still a bit of a rough idle. Still getting the P0410 code every day.

http://www.justanswer.com/questions/1og ... rvice-code

http://gearchatter.com/viewtopic10032.p ... 090ece193b

Maybe I have a bad O2 sensor?

I am going to use my multimeter to check the voltage at the air pump. I can hear it running, which is weird why the code pops up. I am thinking my O2 sensor is not sensing that voltage drop.

[ptrfair]

It could be a bad O2 sensor. the MAF would make sense, i had the SAME problem however once the sensor was replaced everything was solved...in your case id investigate the O2 sensor...its going to be needed one day anyway.

[JBMark33]

It could be a bad O2 sensor. the MAF would make sense, i had the SAME problem however once the sensor was replaced everything was solved...in your case id investigate the O2 sensor...its going to be needed one day anyway.

I disconnected my battery when I came home tonight. I am also having some rough shifting after a transmission fluid and filter change. We shall see what turns up tomorrow. I might have to contact haro for an O2s.

I checked the underhood fuse for the air pump and it is good. I can also hear the air pump working when I turn on the vehicle. Also, the only time this code is set, is when I am letting off the gas to coast. I have extra devices under my hood with plug connections for managing vacuum for its different components.

Here are some pics of what my engine setup looks like.

1- Air pump
2- Metal pipe to the check valve and exhaust input
3- where the pipe goes



4- Is this the check valve? (has elec. connection)
5- I don't know what this is either. (only has vacuum connection) [takes air pump pipe and sends to exhaust manifold]
6- vacuum line from brake booster connection to UIM
7- vacuum line from #5 to #4



I guess I am trying to identify #4 and #5 to continue troubleshooting this issue.

Here are more pictures of those connections/devices.



BB = from Brake Booster


EM = Exhaust Manifold


UIM on right. CV = Check Valve.

[ptrfair]

When the trans was serviced...was it Flushed or was the fluid just changed? A flush can cause hard shifting sometimes. My family's shop has seen some issues with that, customers taking their cars where they flush the trans and then it drives rough. Hows them motor mounts....especially the front trans mount?

[JBMark33]

Here is my update on the tranny.

http://www.pontiacbonnevilleclub.com/fo ... 18&t=11731

The mounts are all good. I put in Seafoam's transtune a month ago; then on monday I dropped my pan and replaced my filter and fluid.


-- I wish there was a way to test my O2 Sensor without just blindly replacing it.. Also, is it possible to tune the air pump out of the pcm? The air pump is only needed in NY and CA for emissions. I live in PA.

[JBMark33]

Okay, so I installed the check valve backwards when I replaced the vacuum hosing elbow that broke.

See how the white is facing the firewall? I had it facing the UIM.



Hopefully this will cure my CEL light.

I still have some kind of rough idle, but not sure why. I am going to test my coil packs.

[Archon]

What things have you already done that could affect how it runs at idle? Things like plugs, wires, vacuum leaks, wiring routing....

[JBMark33]

What things have you already done that could affect how it runs at idle? Things like plugs, wires, vacuum leaks, wiring routing....

I hydro-locked the engine sometime in January or February. When I replaced my UIM and EGR sleeve with the reduced diameter stovepipe, I used champion plugs for the first 500 miles to burn out any remaining anti-freeze.

I then put in my ACDELCO iridium plugs that I love so much. I re-routed my wires around the O2 sensor and just fixed a couple clips since I put everything back together when it was 18* out in my driveway. I am going to test the coils in a few moments. The wires are new as of June 2008. I did have to swap the plugs in and out ALOT trying to get the engine to fire back up. It is possible that I damaged one of my wires. What's the safest way to test a wire?

I am also pretty sure I don't have any vacuum leaks. I replaced all my cheap plastic elbows and connectors with good, solid rubber hosing.

[JBMark33]

My coil packs tested out to be (from the top down) 6.68, 6,41 and 6.34 when testing the secondaries.

[RookieSSei]

i have some of the same issues like my rpm is very high when i start my car so when i put it in gear it almost thrust into gear but if i wait a couple of sec and let the hand drop below 1500 rpm it shift not so bad ? what would cause this ?

[Archon]

With vacuum leaks, I was thinking along the lines of gasket leaks. Did you do the LIM gasket when you did the upper. Looking at the pictures, it appears as if you could have some coolant seeping around the LIM.

[JBMark33]

i have some of the same issues like my rpm is very high when i start my car so when i put it in gear it almost thrust into gear but if i wait a couple of sec and let the hand drop below 1500 rpm it shift not so bad ? what would cause this ?

For me, it was a bad MAF sensor.

With vacuum leaks, I was thinking along the lines of gasket leaks. Did you do the LIM gasket when you did the upper. Looking at the pictures, it appears as if you could have some coolant seeping around the LIM.

Hah. Good news, those pictures are old. My idle is gotten a little better but it still will rock around a little every 3-4 seconds.

Noticeable to me. I wonder if I am nit-picking or if its normal.

[RookieSSei]

did it give you a code? for the maf ?

[JBMark33]

The code did not set the CEL light nor did it store it in the computer memory.

The only way I was able to track down my issue to the MAF sensor was to keep clicking "scan codes" on my mactools pocket scan tool while I was driving. The code that I was able to come up with was: P0100.

[JBMark33]

I think I found out why my rough idle is still occurring.

While spraying carb. cleaner around under the hood, I as able to re-create the problem by spray carb cleaner around the bottom of the cylinder #6 fuel injector. I think I have tired O-rings all around. The engine started missing when the carb cleaner got in there. All the other injectors were fine, but I should get a set to be safe.

And now... video footage of said phenomenon.

[JBMark33]

This is what normal O-Rings look like right???





My car continues to surprise me. lol

[00Beast]

That would most definitely cause an issue. It did fix it, correct?

A very similar thing happened when Andrew and I did my LIM gaskets. One of the o-rings got caught and torn, and the engine acted like it was a huge vacuum leak. We put one of the old ones back on, and it worked great after he hooked up the vacuum t under the S/C. The o-ring was part of the issue, lol.

[JBMark33]

I am still getting what I would call a rough idle. I am thinking about seafoam-ing the engine again since I haven't done that since it was hydrolocked.

I am running out of ideas.