Okay, I hope I'm not starting a redundant thread. I've tried to search for this with no success..

This past Monday my 2004 started behaving oddly. The symptoms are:

1. A shudder or studder when RPMs drop below or near 1500. Mainly only happens after she's been parked for a while, such as first thing in the morning or after work. It seems to become less frequent after running for a bit, such as after driving home on the Interstate.
2. On Monday, after starting up to go to lunch she shuddered when slowing down in the parking lot and then died outright when I came to a stop. She restarted immediately after ward.
3. There is a noticeable lurch forward at times when coming to a stop.
4. She makes this, noise, when the RPMs get low while moving. Up shifting to raise the revs makes it go away.

I think that's everything. The symptoms above don't happen all the time and she's only completely died once. Though, if I had to describe what happens when I'm coming to a stop I would say she acts like she wants to stall and die.

I've been wondering if this could be caused by bad gas? I filled up Friday afternoon from a place I haven't gotten gas from before. Then I went home after work and didn't go anywhere over the weekend. The whole drive home she was fine. Yet, there were problems first thing Monday morning. After she died I honestly thought it was the CPS, having had that problem before. I immediately replaced it, but the problem persists.

Any suggestions or ideas? Thanks in advance.

 

Have you checked for any codes being set? That's the first place I would check.

 

Not as yet. I don't have any CEL or anything, though I suppose I could have codes anyway, yes?

I have a friend with a code reader. Probably drop by his house and check them.

 

Okay, got her scanned on the way home. No codes given.

 

Hate to keep replying to myself. I'm hoping it is just the bad gas. I've added new gas from a known good source. Hoping for the best. There has been no change as yet.

 

My first guess was CPS but you said you replaced that.
How about the flywheel?

LINKY

 

We know little about this car, auto, manual, mods.
More info is required.
I had trouble after filling up at a new to me gas station and that sent me on a wild goose chase, turned out the gas pump was not putting out enough pressure. New pump solved the issue after a frustrating year.
The pump may not be your problem, but my low pressure caused a lack of fuel when it needed a richer mixture.

 

Not sure if this will help, but a visual inspection is definitely in order, with a good light.

I had the same problems you are describing not even a week ago, I thought for sure it was the CPS but after a thorough inspection, I found the MAF sensor at the back of the motor (rear circular item the air box sits on) had barely come off the block. It was very difficult to tell it was off, because it was only on the bottom, I fit everything back together and made sure the clamp was on correctly, no issues since.

I do think bad gas is a possibility though.

Like Dave said, we need more info, miles, condition, tranny, mods, etc.

 

I'll take a look and see if I can find the MAF and see what it looks like.

Sorry, I did forget to include details.

Year: 2004
Transmission: Auto
Miles: 107,000ish
General Condition: Until this issue, no problems.
Mods: None (yet.. )

 

To sound a little redundant.....have you changed the battery? Dying batteries give all sorts of problems. If it's bad gas you can try either a fuel drying additive (alcohol) or some Techron.

Let us know what you find & good luck.

Xfirepop

 

No, haven't changed the battery. I have thought about it, however the one in there isn't that old and I don't recall any other issues that would indicate a battery problem. Though, you are correct that it can generate weird problems.

The fuel drying additive sounds like a good idea and I did add some. We'll see how it goes in the coming days. I do hope that is all it is.

 

I eyeballed what I think is the MAF. It looks to be fully on there and attached. I'll take a closer look at it later at home and report if there is anything odd about it.

It also died on me again when coming to a stop just a few minutes ago.

 

Without more facts, I would go Boiler-up's idea, sounds like possibly an air leak in the intake system somewhere. Air leaks on these cars cause funny symptoms, do some thread searches.

 

Guess: may be time for new plugs. A tank of bad gas could certainly cause problems. Drygas or fuel injector cleaner may help for the next tank. Could be a plugged fuel filter. Check the maintenance book for services at 100k.

 

I'm giving more time for the fuel additive to do its thing. However, it may be my imagination but I think it is getting worse..

It gets much worse and I'll have to just suck up the bill and take it to the shop. Can't say I know any good trustworthy ones in the area.

 

It would be nice if members would add their locations in their profile.....

 

I had something like that the other week. Turned out to be...and I kid you not...that the engine cover and its air tubes were not on tight thus creating a vacuum leak. Car had just been serviced at the dealer and the tech didn't make sure the cover was all the way down. I would check that and make sure all hoses are connected correctly.

 

Nashville, TN area

 

I'll take another look at that. You're referring to the airbox when you say the engine cover, right?

 

I have had my engine cover not pushed down and I never had any trouble at all, I just noticed it a few days after I got the car. The car would be using some non filtered air at a very slightly higher pressure that's all.
I really cannot see why that would make much difference, and when you say vacuum leak it makes less sense to me.
I should add that Boilers problem would make sense as his car would be using unmetered air.