My 1994 Z28 started to ride rough about a week ago. Then, it suddenly started stalling at stop lights and idling low then high. I took it to the mechanic to get my intake manifold gasket replaced since I did not have time due to work. When I went to get my car, they said they had replaced some vacuum hoses because they were worn. I assumed this would fix my problem because bad hoses can cause rough riding and stalling. I drove the car and it drove great, than it went bad; fast. My car is stalling more now and idling even worse. Could this be because the mechanic didn't fix the hoses correctly, or do I have another problem?

 

Also, does anyone have a diagram of the vacuum hoses?

 

Only at idle? Check all the senors around the intake manifold, idle air control valve?

 

It runs very rough while driving also, but not until it is warmed up.

 

Hmm, I'm not the expert here but I'm tryin my best just so ya know, check the throttle position sensor also and if you have the stock paper filter take it out and beat it on the ground til its clean

 

What codes do you have, if any?

 

I do not have any codes. It runs great for a while but then gets horrible. It rides really rough and wants to stall when I start to slow down.

 

How are your plugs your opti? They could of damaged it when they took your manifold off and the plugs could just be fouled out or worn.

 

Well, I changed the thermostat about 2 weeks ago and right after that is when all of these problems arose. So I am going to take it out and see if it is stuck shut. I'll keep you updated.

 

The t-stat won't be the idle problem. Could be causing the rough running when warm tho.