My engine started idling a little odd. Soon the CHECK ENGINE light came on. When I was coasting the engine would idle high and lag, idle high andlag. It would give a surge of acceleration and then idle, continuously going through that cycle as I let it slow down coasting. The cycle is rhythmic and not erratic at all.

When I accelerate there does not seem to be any power loss issues. It has been so long since I have driven the truck, but it did seem a bit sluggish. I attributed that to the old fuel. It seemed to be a bit better with the new fuel. I was planning on putting in new spark plugs and wires, because it probably needs them. I do no think that the previous (the only?) owner followed a lot of the proper maintenance.

I had the vehicle parked for about 20 months and had just fired it up this week. It was running fine for the last 2 days until now. When I first started it, there was a lot of white smoke, but that seemed to go away after a few kilometers of driving. I had finally put in new gasoline today, but I don't think that would cause the problem.

I turned off and restarted the engine once I got home, but that didn't change anything. I will obviously try again tomorrow morning.

I think it may be a spark plug. I have no idea when the spark plugs and wires were last changed. The vehicle is at 280,000 kms. I was planning on changing them very soon. The fact that the problem is very rhythmic makes me think it may be a spark plug or wire issue.

The vehicle is a 1994 S10 Blazer 4WD with a 4.3L Vortec V6 CPFI (W engine code). What do you guys think the problem might be? Or how could I further diagnose the problem?

 

I have an Engine Code 32: EGR Valve (Exhaust Gas Recycling).

The power surges are the exact symptoms described in my S10 Manuals. It doesn't look too hard to change out, but it is an expensive part.

Does anyone know if this is a part that needs to be changed immediately? I would like to order one online to save money. Of course this had to happen on a Friday, over the Christmas holidays!

 

I would clean the EGR valve and seeif that helps.

 

Good idea. I will see if the valve is not sealed and cleanable. If it is, I will order a brand new one online at a good price.

 

I started up my truck and the check engine light did not go on. I let it idle for about 30 minutes. It was doing the same thing.

I got in the truck and drove around the block. The valve must have been stuck, because it is idling and driving normal now. The temperature is -20 Celsius, so that might have something to do with it. If it happens again, I'll be removing the valve and cleaning it. I might do that anyways, when I have more time. In the meantime I am hoping my truck runs reliable!