I have a 1993 4.3 V-6 GMC Sonoma Pickup with 37K running rough, why?

[metalsuitman]

I bought used with 36K and it had some stumbling problems when applying the gas. I thought it was the gas filter as I was not sure it had been changed for sometime but that did not seem to fix the problem. Tonight after a hard rain all day, and though the truck was in a garage which is damp, I went out shopping and it was stumbling a lot. I usually keep the gas tank full as was the case this time but I still had the problem. I am thinking it was a bad load of gas or the injectors need cleaning so I was going to run the tank almost empty and put in injector cleaning solution though I am not sure these products are effective. I also considered it might be spark plug wires which when damp can give a symptom like this. What would you consider first as a possible solution to this problem? I know the truck is old but with low mileage and am not sure if most of its' life was spent outside. By the looks of it I think it must have been under a carport at least because the body is in good shape though the paint is showing age. There were wasp nests in the door jams too so assume it sat a bit and of course was not driven often. The owner just passed away and he was 61 when he bought it new in '93. Any help would be appreciated. I hope I have given enough information. Thanks.

 

[Molson02536]

I bought used with 36K and it had some stumbling problems when applying the gas. I thought it was the gas filter as I was not sure it had been changed for sometime but that did not seem to fix the problem. Tonight after a hard rain all day, and though the truck was in a garage which is damp, I went out shopping and it was stumbling a lot. I usually keep the gas tank full as was the case this time but I still had the problem. I am thinking it was a bad load of gas or the injectors need cleaning so I was going to run the tank almost empty and put in injector cleaning solution though I am not sure these products are effective. I also considered it might be spark plug wires which when damp can give a symptom like this. What would you consider first as a possible solution to this problem? I know the truck is old but with low mileage and am not sure if most of its' life was spent outside. By the looks of it I think it must have been under a carport at least because the body is in good shape though the paint is showing age. There were wasp nests in the door jams too so assume it sat a bit and of course was not driven often. The owner just passed away and he was 61 when he bought it new in '93. Any help would be appreciated. I hope I have given enough information. Thanks.

Start with the simple and clean or replace your EGR valve, and here is a link that should help you get your Sonoma running 100% again.

Good luck and keep us posted.
http://gmcowners.com/gmc-forum/showthread.php?t=13770