1995 Chevy van conversion motor vibrates at low speed
 

Hi everyone, good to be part of the Chevy fans community. I am new here, becasue I just bought a 1995 Chevy van conversion to go on road trips !
I am very excited, but I need some help from you guys since no one in my little town can find out what is going on. It has the 5.7 V8 engine.
The van has less than 100,000 miles on it but it seems to me that it hasn't been cared that much.
The motor vibrates a lot when it is at low speed, and even more when stopped. It doesn't vibrate when I accelerate though. It worries me since I am going to drive it to California (I am in Arkansas).

Anyway, any kind of advice would be great before taking it to a mechanic in a bigger city.

Thanks a lot !

Emmanuel

I assume you means it idles rough.
There are a few simple things to check to see whats up.
Check your air filter, and pcv valve.
Check your spark plugs to see if they are old and worn.
Check the spark plug wires for signs of arcing.
How old is the fuel filter? Change it if unsure....same with the parts listed above...
Also there could be a vacuum leak.
A trick to finding that is to use a propane torch, like for plumbing and let a little propane out along the intake manifold.....if the idle speed increases, the propane is getting sucked in through the leak.....find it and fix it.
But check the basic things first.

Yes thanks for the vocabulary, I looked it up and that's it it idles really rough on drive and a little less on park.
Anyway, since I just bought the vehicule I got it completely tuned up today (plugs, wires, filters...) but it still idles rough.
I guess I will try to find out about the vacuum leak then.

Thanks a lot again,

Sure no prob.
By the way, it idles less rough in park, because the engine is not under the load of sitting in drive and not moving.....
Is it rough enough that when you give it gas is stumbles, or does giving it gas make it run smooth right away? If its mild, then maybe a bottle of fuel injection cleaner might help...

Hi, to answer you, it doesn't really stumble actually, which is good I guess.

I will try the fuel injection cleaner this afternoon. The update today is that after the tune up, instead of a steady idle, now it idles discontinuously.
Also, I hear irregular bursts in the engine, at any speed...

I'm kind of scared ...:confused:

Thanks again

Edit : A plug was wired wrong, which explains the new problem. My mechanic told me he didn't hear no vacuum leak, and told me I could use fuel cleaner, which I did. I will let you know if this crazy idle keeps being so rough.