Hello, all. Newbie here with a couple of questions.

My 94 GXE got vibrating problem while waiting for traffic light, but it disappears when I change to P or N. Tune up was done three weeks ago. Could that be my engine mount? or something else?

BTW, I bought this babe from a small dealer who didn't have the manual. I am just curious, does my car have a timing belt or timing chain? Where can I find a online manual?

Thanks in advance.

 

Belt, possibly bad injectors.

 

Sounds pretty serious, doesn't it? Should I just use some fuel system cleaner to clean it? If no improvement, should I just replace them? It's got to be expensive, isn't it? Can I DIY?

 

there should be a chilton in the stickies (hopefully it's working again) injectors can be picked up reman for less than $50 ea and it is DIY

 

This happens to me too, though I don't think it is a problem, but rather just the VG's low idle. I mean sometimes when in drive and sitting at a light my idle goes down near 600. Once you give it some gas or switch to Park/Neutral all is smooth again.

I remember somone else on these forums made a similar thread, about vibrations in drive when stopped at a light or whatnot. I think they had a problem with the front brakes not grabbing well enough or something. Don't ask how that has anything to do with the idle because I have no clue, but apparantly they fixed the vibration by bleeding the brakes and readjusting them or something like that...

But again if your "problem" as you call it is anything like mine then I think it's just low idle.

 

That was me with this vibration problem. And yes air in the front breaks could cause vibration because after all it is a front-wheel drive car, isn't it?
After bleeding the breaks vibration was gone (I believe the sequence is front RH, rear RH, rear LH and finally front LH - but check the manual).

But it might be one/several of the engine/transmission mounts also.

Talking of the low idle (under load; i.e. in the gear, a/c on, etc.).
There are a few things to check:
- throttle position sensor / throttle body parts clogged
- idle control valve
- EGR valve leakage
- bad PCV valve (DIY and inexpensive to replace)
- vacuum leaks
- air filter clogged
- bad injector(s)
- bad fuel pump
- timing belt worn
- etc.

 

That's exactly what happens to my baby, vibrating a little, but smooth again when I drive or P/N. I think I'm just a little bit over cautious. Thanks a lot.

 

Oh, man. That's such a complete check list. I will save it just for my future reference. I think I can change those cheap stuffs, like PCV valve for sure. It is an old car anyway. Again, thanks a lot for such detailed check list.

 

I'd run some fuel injector cleaner through it. Consider throttle body cleaning.