HI ..looking at a gmc 2000 sierra pickup 4.3 l engine v6... almost 260,000 miles on it.
The check engine light comes on..gave the code of po300 random misfires..
Before anyone gives this truck grief..it ran like a champ a week ago..could easily do 70 without any hestitation/problems/no leaks/no odd smells or noises!
Now It idles rough...staying about .5 instead of like .9 or 1.0, ..it is really lugging when the accelator is applied/goes down an octive in noise. It has a distributor whose rotor was completely blackene ( i put a new one in today/put in a new cap)..I put in a new coil pack as well. I found all 6 spark plugs were completely carboned ( the plugs and plug wires were replaced 6 months ago). Should I also replace the plug wires?
Put a new fuel pump in like 2 years ago..put in a new fuel filter and gas treatment incase I got some bad gas.
Someone suggested that I have a vaccume leak..Well I did the joe average smoke test and couldn't see or smell any smoke coming out anywhere on the engine..my friend put about a cigarettes worth of smoke in the system..took our smoke hose off and it poured out..system seemed very closed to me. He smokes that really cheap cigs so one could have smelled them if it came out of the system underneath.
So what would cause a distributor cap to burn out like that.. I don't think it is a fuel pump and I don't smell any gas in the cab or under the hood ( don't think it is like a fuel injector problem)
A few days ago the truck could go down the road 50 mph and pull a hill then it developed this lugging problem going up hills/had to put my foot into it and that probably caused the dis rotor to burn out/blacken the sparkplugs. Now the problem has progressively gotten worse ( haven't driven it in like a week ).
So what's your best guess? thanks
The check engine light comes on..gave the code of po300 random misfires..
Before anyone gives this truck grief..it ran like a champ a week ago..could easily do 70 without any hestitation/problems/no leaks/no odd smells or noises!
Now It idles rough...staying about .5 instead of like .9 or 1.0, ..it is really lugging when the accelator is applied/goes down an octive in noise. It has a distributor whose rotor was completely blackene ( i put a new one in today/put in a new cap)..I put in a new coil pack as well. I found all 6 spark plugs were completely carboned ( the plugs and plug wires were replaced 6 months ago). Should I also replace the plug wires?
Put a new fuel pump in like 2 years ago..put in a new fuel filter and gas treatment incase I got some bad gas.
Someone suggested that I have a vaccume leak..Well I did the joe average smoke test and couldn't see or smell any smoke coming out anywhere on the engine..my friend put about a cigarettes worth of smoke in the system..took our smoke hose off and it poured out..system seemed very closed to me. He smokes that really cheap cigs so one could have smelled them if it came out of the system underneath.
So what would cause a distributor cap to burn out like that.. I don't think it is a fuel pump and I don't smell any gas in the cab or under the hood ( don't think it is like a fuel injector problem)
A few days ago the truck could go down the road 50 mph and pull a hill then it developed this lugging problem going up hills/had to put my foot into it and that probably caused the dis rotor to burn out/blacken the sparkplugs. Now the problem has progressively gotten worse ( haven't driven it in like a week ).
So what's your best guess? thanks
