I need help. Something doesn't seem right.

[ice745]

I had an exhaust leak, so I took my 94 4 cyl to my mech to get fixed. I figured I'd have them do fuel filter too since its at 70k and I don't think its been done before (bought it used). Before I took it there, the car would kinda shake (the engine sounded fine, just the car shook for some reason) a lil if I was stopped and still in drive and it would idle at 800 RPM, putting it in neutral (automatic trans) would smooth it out. While in neutral it would idle at about 1k to 1.2k RPMs, which seemed nice. Now after getting the exhaust fixed (same cats, just a new flex pipe) and the fuel filter replaced, the car stops in drive fine, but if its in neutral it idles at 1.7k to 2k RPM!! It sounds like I'm putting my foot on the gas a bit. I kind of made a habbit of stopping in neutral since I used to have to for it to idle smooth. Do you know why it may be doing this? And is stopping in neutral a bad habbit?

Currently, I'm assuming from the temperature change (YAY SPRING!!) my Antefreeze is above the full mark by about an inch in the resevoir. I am going to take some out and see if that helps.

Thanks for any help.

[jsinton]

Sounds like somebody bent the linkage when they did the fuel filter. It should idle at 800 regardless of it's in gear or not. It's computer controlled idle, unless it's getting too much air, then it will idle faster. Check the linkages around the throttle wire. Idling over 800 could burn up your trans sitting at the light.

[ice745]

Hmm, strangest thing. I didn't see anything bent, I didn't exactly know what I was looking for. I drove it around a little bit, I was sure to never go into neutral so it would stay at 1k RPM. Came out of Target, started it and immediately put it into drive so it didn't rev up. Was about to go forward, but someone blocked me, so I stopped, and the RPM dropped to about 200. I was nervous I thought it was gonna die, I let it sit for a few seconds, didn't move. Then I put it in neutral thinking it would work, it went up to 800 RPM. Back to drive, and it stayed at 800 RPM. Now its always at 800 RPM no matter what (unless of course I'm giving it gas). Its never been this good before. I wonder if maybe the fuel filter just needed to break in or something.

[jsinton]

No, it wasn't your "fuel filter breaking in", that's for sure.

[Mike Gerber]

Several things come to mind. First off is a vacuum leak somewhere. Getting to the exhaust or the fuel filter they could have moved some vacuum lines exposing some crack or cracks. After all, the car is now 11 years old. With the car running, I would move around the vacuum lines, especially near the fuel filter trying to duplicate the problem. If you can, replace the vacuum line you last moved around.

The second thing would be to find out if they disconnected the battery for any length of time when replacing the fuel filter. Some shops do this as a precaution. I had a situation with a Mazda Miata where disconnecting the battery for about an hour caused similiar symptoms to what you are describing. After about a half hour of driving, the symptoms dissapeared. It seems as if the computer had lost it's memory and has to relearn your driving habits. It apparently takes several minutes to half an hour to do this.

Just a couple of educated guesses here.

Mike

[Brian R.]

I think Mike hit the nail on the head with the ECM learning your driving habits.

[ice745]

Thanks everyone for all the help.

[DustenH]

my 95' Camry shakes too when in drive and stopped.. when in Neutral the rpms go up a bit also.

[Mike Gerber]

DustenH,

If you have a 4 cylinder 5SFE engine, this is normal behavior.

Mike