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2000 Pontiac Montana

What is causing the engine to sound like it’s not getting enough gas AFTER we turn off the A/C? The two times we have used the A/C, after we push the button to turn it off, the engine sputters like it is going to die … sounds like it is not getting enough gas. It has over 178,000 miles on it and it sat for about three years before it was given to us.

I am sorry but we need more details, the only think I can think of right now is a dirty or clogged IAC (Idle air control) valve…

Does this happen only at idle? Does it happen when driving at 30 or 50mph?

It does happen when driving. Yesterday I could not go past 20-25mph. It seems ok when it idles. The more I would try to accelerate, the sputtering would get worse.

What was done to it after it sat for 3 years and before putting it back on the road? Nothing? In addition to that, what was done to it for the first 10 years & 178K miles? How old are those spark plugs & wires? Filters? Was it run on that old, stale gasoline in the tank after sitting? Any fluids changed out? You can’t seriously expect anyone to give you much intelligent advice on a vehicle with this kind of history if you don’t provide info - can you?

If it didn’t go to an actual mechanic to be put back in order before putting it on the road, then just take it to a good, local, independent shop. Get a full round of maintenance done on it. Plugs & wires, filters, all fluids changed out. Have the fuel pressure checked. Brakes checked (include new brake fluid in the fluid changing).

We are bringing the van “up to speed” as money allows. We had someone look at it and we have a nice list of things that need to be done to it. Before it was parked, maintenance was done regularly. Next on our list is changing out all fluids except oil because that was what we took care of first. We know the Serpentine belt need changed out as well as fuel filter changed. There wasn’t much of the old stale gasoline in it. Air filter has also been changed. It needs two tires. We haven’t gotten to the plugs and wires yet.
Cigroller, I am doing the best I can. Please be courteous and and cut me some slack! If you would like other info just ask nicely!

I would move the tune up way higher on the list. If your wires are toast you can actually damage the motor because it will try to ignight fuel at the wrong time. If you can’t get the van above 25 mph then the van is a danger to you and others on the road untill it is fixed. If you can’t afford it dont drive it, you run the chance of making it much worse. In cig’s defense we see posts like this all the time where people gave an issue but give no details. It makes it very hard to help, keeping in mind we all do this for free because we like to help people. Basically help us help you !!

Ps here is a test for you. Tonight park in a dark place pop the hood with the motor running. See if you can see a light show (blue dancing lights mean the wires are leaking electricity) by the spark plug wires.

Since the AC on/off seems to trigger some bad symptoms there could be issues with the AC system itself. When you hit the switch to turn off the AC the cars computer sends some signals to anticipate that there is going to be less drag on the motor. If, the compressor clutch mechanism is stuck and the compressor keeps turning that might cause your symptoms.

Putting the car back into service after a 3 year layoff is bound to have issues until you sort through all the problems one by one. You really need a local mechanic to help you troubleshoot the problems as they pop up. New plugs, ignition wires, and a check on the fuel injectors for proper function should be done soon. The stale gas might have varnished up the tiny holes in the fuel injectors. Same varnish can also cause little valves and fuel lines to stick and clog up.

As you solve a problem, it will run better but you’ll encounter another problem shortly thereafter.

"Cigroller, I am doing the best I can. Please be courteous and and cut me some slack! If you would like other info just ask nicely! "

I was being nice.

Change the fuel filter, spark plugs & wires now, and have someone get a fuel pressure gauge on it.

To add to cigroller’s last post, I would also recommend a vacuum test to rule out a plugged or melted down catalytic converter, since you state you cannot make the van go more than 25 mph. This could very easily be caused by a plugged catalyst.

Mark’s addition to the basic list is a very good one. Cheap and easy too (if you find anyone that knows how to use a vacuum gauge. Check the dudes with white hair).

I don’t want to give you advice- I would make you cry.

Wow! Thank you to everyone for your help. Now we have an excellent idea of what to do next! Thanks again!