Truck had bad miss, sluggish & check engine light illuminated. Everything related to ignition was changed (plugs chgd twice), no help. Took truck to Chevrolet dealer in Columbia, TN for repair. Shop manager (30 years with GM) diagnosed the problem almost immediately. Distributor drive gear was worn badly allowing the timing to vary by as much as 10-12 degrees. Changed the gear assy...problem solved. VERY IMPRESSIVE Thought everyone with the 4.3 should know about this fix. Apparently this is a common problem with the 4.3. My truck is a 2000 Silverado with 115,000 miles. Runs great now.

 

How hard of a fix is this? Did you DIY or did the dealer do it? What was the cost?
Thx, Wizard

 

If you are a mechanic & have the tools, I suppose you could do it youself.
The distributor has to be removed & the drive gear replaced. I had the dealer do the work since I do not have the proper tools. Cost was $277.60, parts & labor.

 

Not a bad price, part is around $85.00 at Autozone. Pulling the distributor looks like a real PITA. It is buried between the firewall and engine. I'll probably have the dealer do it. Thanks

 

The cost of the gear from Chevrolet was $69.00+ (don't remember the cents). The rest of the cost was labor, misc shop supplies ($17.00) & taxes.

 

Truck is running perfect with good power and gas milage. Pulls hard to redline in 1st and 2nd gear, but at about 4000rpm in third engine light starts flashing and won't pull past 4.500rpm. Shift to 4th and light goes out, then into 5th and cruises fine, WTF. I think I might try replacing the coil. Random missfire only in 3rd at high rpm?

 

Could be you are running out of fuel. I once had a car that did the exact same thing. Pulled like crazy in 1st & 2nd gear then would not run in 3rd. Turned out, full throttle in 1st & 2nd was pulling all the fuel out of the fuel line. Electric fuel pump cured the problem. (the car did not come from the mfg. with an electric fuel pump. It was 70 440 Dodge Charger.)
Have you changed the fuel filter? If you haven't, that is the next thing I would do. Fairly inexpensive & could be the source of you problem.

 

i have black smoke coming out of my tailpipe and it idles rough . converter was clogged when i got a new one put in thats when black smoke started. i have replaced wires & plugs[not the cap & rotor] and replaced the 02 sensor before the converter ...any ideas of whats going on

 

Thanks for the fuel filter tip, JPT. Makes sense, probably never been
changed and cheaper than a coil.

 

bubba army,
Without more info, hard to tell what the problem is. Is the computer throwing a code? Is the "service engine light" illuminated? Advance Auto will pull the code for free if you can get the vehicle to them. The "code" will give you a starting point to help diagnose the problem.