JimR
Elite Member
I need a smart GM mechanic\'s help
My son came home Saturday night from D.C. with my 2000 Blazer S-10 4.3 V6. The engine light was on. I took it down and had it checked at a parts store. They said that it showed the truck was skipping intermittently and that one of the 02 sensors was gone. I figured with 120K on the truck I'd change all 3 sensors and end that problem. I had the light reset and it still drives like an underpowered vehicle. The motor has only 12,000 miles on it. I replaced it last year with a brand new complete engine. If you are driving on flat ground it stumbles on take-off unless you floor it. As soon as you try to pull a hill it has no balls whatsoever and may misfire. In 2nd gear it will wind out to 3800 rpm's tops. The fuel pump is fine and tested fine. It has a new fuel filter also. I also replaced the spark plugs. I see no loose vacuum lines or anything else wrong with it. The timing is non adjustable and it does advance when revved up. The motor will redline in nuetral with no problem. The engine light is back on again now for the same reason, misfiring. Yesterday I took the truck to the local Chevy dealer. It cost me $120.00 to have them tell me they found the catalytic converter was plugged. they wanted $1006.00 for a new one. I welded in a universal one today for under $80.00. Now I have replced a perfectly good converter only to find out the truck runs the same. Seeing how I have a complete motor in my garage with all the relays,switches and do-hickies on it, I figured I'd swap out a few to see if they made any difference. Knowing that the truck stumbles when you take off. I replaced the TSP throttle position switch. No change on that one. Then I thought maybe it might be the EGR valve. So I swapped that one out. No change on that one either. Next was the MAP sensor. Same old thing, just another switch. Then I got a bright idea and decided to disconnect the wire on the EGR valve. Bingo, the truck runs almost like new again. Hmmm, $120.00 for diagnostics at Ragsdale Chevrolet to tell me a perfectly good catalytic converter was no good. I'll be visiting them in the morning to either get my money back or have them find out what the real problem with my truck is. I think it may be the VCM Vehicle Command module that is bad. Hopefully they can run a test with their meter to check this out. I'm really glad that I didn't fall for their $1006.00 catalytic convertor job. I could just see the smoke boiling out of my ears when I would have picked the truck up to find out it was running just like when I dropped it off. I guess I'll have to teach them how to test drive a vehicle. Anyone have any ideas as to what can cause this other than the VCM? There is power to the EGR with the key on and the vehicle not running.
My son came home Saturday night from D.C. with my 2000 Blazer S-10 4.3 V6. The engine light was on. I took it down and had it checked at a parts store. They said that it showed the truck was skipping intermittently and that one of the 02 sensors was gone. I figured with 120K on the truck I'd change all 3 sensors and end that problem. I had the light reset and it still drives like an underpowered vehicle. The motor has only 12,000 miles on it. I replaced it last year with a brand new complete engine. If you are driving on flat ground it stumbles on take-off unless you floor it. As soon as you try to pull a hill it has no balls whatsoever and may misfire. In 2nd gear it will wind out to 3800 rpm's tops. The fuel pump is fine and tested fine. It has a new fuel filter also. I also replaced the spark plugs. I see no loose vacuum lines or anything else wrong with it. The timing is non adjustable and it does advance when revved up. The motor will redline in nuetral with no problem. The engine light is back on again now for the same reason, misfiring. Yesterday I took the truck to the local Chevy dealer. It cost me $120.00 to have them tell me they found the catalytic converter was plugged. they wanted $1006.00 for a new one. I welded in a universal one today for under $80.00. Now I have replced a perfectly good converter only to find out the truck runs the same. Seeing how I have a complete motor in my garage with all the relays,switches and do-hickies on it, I figured I'd swap out a few to see if they made any difference. Knowing that the truck stumbles when you take off. I replaced the TSP throttle position switch. No change on that one. Then I thought maybe it might be the EGR valve. So I swapped that one out. No change on that one either. Next was the MAP sensor. Same old thing, just another switch. Then I got a bright idea and decided to disconnect the wire on the EGR valve. Bingo, the truck runs almost like new again. Hmmm, $120.00 for diagnostics at Ragsdale Chevrolet to tell me a perfectly good catalytic converter was no good. I'll be visiting them in the morning to either get my money back or have them find out what the real problem with my truck is. I think it may be the VCM Vehicle Command module that is bad. Hopefully they can run a test with their meter to check this out. I'm really glad that I didn't fall for their $1006.00 catalytic convertor job. I could just see the smoke boiling out of my ears when I would have picked the truck up to find out it was running just like when I dropped it off. I guess I'll have to teach them how to test drive a vehicle. Anyone have any ideas as to what can cause this other than the VCM? There is power to the EGR with the key on and the vehicle not running.
