Chevrolet Astro Van

[KB9UDE]

Hi all
I am working on my parents 1995 Chevy Astro van. It idles rough, but runs decent at higher rpms. What do you think it could be??

John

 

[Bird]

One of my brothers told me about running into a similar puzzle last year working on his son's Astro van, and now I've forgotten what they eventually found the problem to be, so I've sent him an e-mail to ask what it was.

 

[woodchuckie]

In the order I would try plugs-plug wires-injector cleaner added to gas- dianostic service checking coils and electronic ingition.

 

[AMP762]

Anything from a vac. leak to a burned valve.

 

[MrJimi]

Is your CHECK ENGINE lite on ?

 

[Bird]

Well, my brother answered my e-mail about the same time I remembered what happened to him last year. You say you're working on the van, but didn't say just what you are doing or have done. My brother was doing a tune-up on his son's Astro van, new plugs, wires, distibutor cap, etc. when he had that same problem. And after a couple of days determined that it was a defective (although new) distributor cap.

 

[CinderSchnauzer]

Check for a broken vavle sring.

 

[George2615]

Most likely a vacuum leak. The hoses dry out, get hard and crack or break completely due to engine heat. Could also be any number of things like an O2 sensor, MAP sensor, plug, wire, or cap, EGR valve, crank sensor, bad gas. I'll go with my first choice though. With the engine running listen under the hood / engine cover for air hissing on the vacuum hoses. Move them around, pull them off and feel for vacuum.

 

[Bird]

Another way I've seen used to check for vacuum leaks is to spray WD-40 anywhere there might be a leak. If it hits a leak, you'll hear the change in rpm and engine sound.

 

[Nasty135]

KB, If it runs ok cold then gets rough as it warms , check EGR valve .. If this is a throttle body injection and not the multi-port (not real familiar with multi's but could be same issue), I would also look at the Base of throttle body where the vacuum lines attach for a carbon build up clog that is choking the vacuum off (usually high mileage issue) also possible O2 sensor or Maf sensor, All this is assuming the airfilter is clean and the pcv is good ... a distributor cap could cause a problem but is generally found to be the culprit under load with a miss. Need more info when diagnosing like engine cold/warm when it misses idle/under load, how many miles, last tune-up etc.

Good Luck

Not a real mechanic , but I play one on TV ...

Oh and I own two Astro's 325K & 190K which means nothing...