2000 sonoma running rich and misfiring, need help asap

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ELVISHOTLINE

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I have a 2000 gmc sonoma that in the last month has a new serpentine belt, bosch plug wires, ac platinum plugs and the brass version of the cap and rotor. It ran great after that. I parked it about a week or two ago. Tried to use it to get to work yesterday and half way to work, the engine light come on. The codes were 101, 300. I have checked some things but donot know where to go. I believe it is running rich causing the misfires. I checked the mass air flow sensor and it is clean. I swapped it with another clean one and got no change. It barely idles.

One tech stated the temp/hot/cold sensor could be failing making it run rich and rough. I only found one on the driver side block area near the exhaust manifold. That one would be for the temp guage and it works. If you would take the time, i really need help because my other truck died inthe morning on the way to work the same day this one started running rich/rough.
 
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Update......

Further checking found no compression in cylinder 6, will check timing to make sure it is not bad.
 
If you have no compression in one cylinder, you have a major mechanical problem. You're not going to solve this with timing changes or changing sensors. Loss of compression is piston rings, piston, blown head gasket, stuck/burnt/broken valves, or a few other things that aren't good either. You're probably looking at an engine rebuild. Heads at least.
 
be careful with the no compression. A bad injector (leaking alot of raw fuel) will wash the cylinder and give it no compression. You need to put a little oil in the cylinder and retest the compression. Also test the fuel pressure and see if it holds it for 10 mins or so.
 
Update

Pulled valve cover found broken rocker arm and bent push rod, valve stuck open, spring not broke........stay tuned and thanks for your input.
 
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