Hi All,

I'm on a roll taking y'all's time so I figured I'd try it again.

Lately, the old girl has been going a little wacky at red lights. You know the drill - stop at the red light and wait for it to turn green.

Virtually every time it will drop 100-150 rpms (from default and functional 750rpms to 600-650rpms) and want to gently lurch forward. This happens whether AC is on or off so I know that's not a primary trigger.

I've been reading about IACV and EACV's on this site. I've also read that drive by wire systems don't have these. The old girl has 190K miles - is there something simple I can do? Something like TB cleaner or something? Just replace a part that's long in the tooth?

Thanks y'all!

 

Get new spark plugs. It has fixed the same issue on another member's car before.

 

Thanks oo7spy....one question. I just replaced those August 2013 along with timing belt and water pump. These were the ones I used:
Napa NGK 6994

Still think I should replace them? If so, I'm thinking of these:
Bosch Iridium SPark Plug

Thoughts?
kingofbytes

 

Probably not the plugs if they are that new. Next caller?

 

I'm going to check the coolant fluid today....I saw something on another board about that. Stay tuned.

 

You can bleed the coolant lines by taking the radiator cap off when cold, running the engine until bubbles stop coming out, top it off again and replace the cap.

 

"You" replaced them or "you had them" replaced... either way something isnt right, the answer will help me place the blame

 

Have you checked/cleaned your EGR valve. Sometimes a dirty EGR valve can cause idle issues as well.

 

OK, so here's some more information:

Had slightly low coolant, put in about 1 cup. No change - idle/lurch issue still happens.

New tactic: When stopped (in D), while it's lurching and RPMs are lower, I've put it into Neutral - car climbs to about 1000rpms quickly and just as quickly settles back to the normal 750. Put it in "D" again and within seconds, after engaging, it goes into the slight lurch with lower RPMs. There are occasions when the car isn't fully warmed up yet, that this issue does not occur. However, once warmed up, it's pretty constant when stopped and in D.

I've put it into reverse as well and the issue does not seem to occur. Of course I'm not in R very long while stopped....maybe I'll try other tactics.

As far as the EGR valve goes, I haven't cleaned it nor am I aware of it being cleaned. Any tips/step by step to do that would be appreciated.

As for the spark plugs, they were replaced by my mechanic.

 

One more clarifier: There is NO ISSUE when in park. Just sitting there in P, and there is no issue - it is only when in "D". Feels almost drivetrain related but I have no idea....

 

is the charging system healthy?

 

Seems OK - Is there a way to check? I just got a new battery last year - Interstate brand.

 

First off remember we are trouble shooting based on your descriptions... we cant see or hear the car... and just to level set... a "new" to you battery doesn't mean a good battery.

Most auto centers can load test the alternator... a drop like that could be electrical or it could also be the idle air control... either way you need to get someone to check it out.

 

Fair enough - I'll do that next week.

The missing link for me is why it does it only when in D and stopped. In N, it doesn't do it. Let's assume alternator is fine....what next? Idle Air?

If so, what's the process to check that?

 

If I remember there are three bolts on the back of the opening where the intake pipe ends.

Honestly you could chase this for a while... a drop could be a load on belt driven components, it could be an issue with fuel, air, or spark...

 

I'm going to post a video in a couple of hours. ..once I shrink it from 150MB. You'll see the exact behavior I am experiencing.

 

How old is your transmission fluid? The gear variable suggests to me the torque converter could be involved.

 

Cool a vid will help, a technician will have a list of "symptoms" that lead to "steps"... so keep in mind its a process.

 

Guys,

I'm trying to upload a zipped MP4 at 10.2MB. The extracted size would be 13MB.

I keep getting this error message:
vBulletin Message
Your submission could not be processed because a security token was missing.

This error most often occurs for one of two reasons. Trying to upload a file, or photo which is too large, and it took too long. Otherwise it can occur if you have been on the page a long time, before submitting your post or pressing the upload button.
Please try reloading the page, and attempt your action again. If you were trying to upload an image, please make sure it falls within the site's size constraints.

Everything looks like it uploads properly and I'm under the 19MB size limit. Thoughts?

 

I'd use youtube, photobucket, or facebook...

 

I would be checking for a vacuum leak.
per your description, as soon as you put load on the vehicle, it gives a funny idle.

 

Could be, especially if the mechanic had it apart.

 

Here's the video link below. I was sitting in a parking lot when I recorded this. As I am shifting, my foot is on the brake the whole time. I never touch the accelerator. Please look for the following:

• Going from "N" to "D". Seems OK, then seconds later you'll see the RPMs drop to 550 or 600 (from around 750). This is the 'slight lurch'. I've shown this 3 times in a row.
  
• Going from "D" to "N" initially jumps to 950 or 1000 then quickly settles back to where it belongs (750).
  
• Going from "N" to "R" shows no issues. Going from "R" to "N" shows no issues.

For clarity, this ONLY happens when going to "D". And it's happening now virtually every time when warmed up.

http://youtu.be/INeZgvpBAEY

 

I had very similar issues on Legend #1 which I believe were combinations of different things. At one point, a mechanic found a plastic vacuum canister that had become detached from its brace and a belt had worn a hole into the side. Make sure you not only check tubes and connections, but check any containers that may be part of the vacuum system.

 

Good info - Car going in on Wednesday next week - I'll mention the issue and potential vacuum leak.

 

I have had a similar drop in idle, but only coming off throttle to coast, usually around 50 to 40 MPH. Some BG44K fuel system cleaner with PEA (polyether amine) helped smooth out the idle. Also, some new plugs, NGK 5787, for the KB2 3.7 helped fuel economy. Both of these seemed to mitigate the idle issue with 90,000 miles on the odometer.

 

I feel like that drop isnt the issue as much as how low your idle is to start with... keep us posted.

 

So magically, the problem has completely gone away after being at the mechanic to cut the rotors, replace the power steering fluid, and replace the propeller shaft.

My head shakes side to side - I HATE not knowing.....we'll see if the problem comes back.