Shaking and idling

[El Prieto Fino]

When the engine is cold, my car starts shaking badly on gear, but the rpm's increases on parking or neutral calming down the car. I have to setup the idle screw to prevent this. But when the engine warms up, the rpm's increases a lot. I don't have the rpm's info because the gauge is gone. Recently I fixed the a/c and The problem is more complicated because the compressor work. I'm having a crazy idle problem. What do you reccomend?

[Mishakol129]

When the engine is cold, my car starts shaking badly on gear, but the rpm's increases on parking or neutral calming down the car. I have to setup the idle screw to prevent this. But when the engine warms up, the rpm's increases a lot. I don't have the rpm's info because the gauge is gone. Recently I fixed the a/c and The problem is more complicated because the compressor work. I'm having a crazy idle problem. What do you reccomend?

I have this same problem right now, its the vacuum actuated motor mount in the rear. If you have an auto like I do that might be your problem. If you have a manual it could be one of the motor mounts, front or rear. It took me forever to find out that it was the rear mount.

If its not any of those, you may have a IACV or a FTIV problem, or a vacuum leak. BUt I wouldn't mess with the idle screw anymore, it never helped me for any of my idle problems before and its glued in place for a reason.

[deevergote]

There's a thread in the beginner technical section with the title "read here first". In that thread, you'll find very detailed instructions on how to fix the very common erratic idle problem our cars often develop. Read that thread, follow the instructions, and see if it helps. Once you've done that, if it doesn't help, we can dig deeper.

[Mishakol129]

There's a thread in the beginner technical section with the title "read here first". In that thread, you'll find very detailed instructions on how to fix the very common erratic idle problem our cars often develop. Read that thread, follow the instructions, and see if it helps. Once you've done that, if it doesn't help, we can dig deeper.

Let him be sure if he has a vibration problem or an idle problem. When my car shook and vibrated, I always thought I had a idle problem but it wasn't, I just never knew how to read the tachometer. I would think the the rpm's were "low" when in gear but that wasn't the case.

When the car is in gear, the rev's will naturally drop, and if you have a bad mount it will vibrate. On the automatics especially, there is a vacuum actuated rear motor mount that changes according to the gear, it can make it vibrate like crazy.

[deevergote]

That is true. Now that I re-read his rather-hard-to-read initial post, I could definitely see where that could be the issue.
Replacing a mount in an old car like this is never a bad idea anyway, even if it doesn't fix the problem!

[El Prieto Fino]

That is true. Now that I re-read his rather-hard-to-read initial post, I could definitely see where that could be the issue.
Replacing a mount in an old car like this is never a bad idea anyway, even if it doesn't fix the problem!

Sorry about My english ... I know it's hard to read, but I still trying to make it perfect.

I did a search before the post, but I didnt read the read this first thread. My apologizes and respect.

I think it's a motor mount too. I put 2 or 3 years ago a cheap ones, because my low budget at that time. But I don't discard any other possibility ....