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Multiple cylinder misfires

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  #21  
Old 05-14-2024, 01:07 PM
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I don’t have pictures but I did look at that and some of the spark plugs back there did look more worn. They had all been replaced at the same time about 2 years ago.
 
  #22  
Old 06-03-2024, 02:37 PM
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I haven't posted on here in a bit but wanted to do some follow up. Unfortunately the PCV valve didn't solve it; that would've been sweet. Upon inspecting the timing belt it does have some visible cracks and when compared to a new belt, does sag a bit. Now comes to the part where I hang my head in shame and admit that I effed up. The camshaft on cylinders 123 is off by almost a 1/4 turn from TDC with the camshaft on 456 and the crankshaft. If you had asked me if I checked that all 3 marks were in line before I removed that timing belt I would have taken a polygraph and said yes. Somehow I was wrong and I don't know how. I didn't turn either camshaft manually and there's no way that thing is moving in it's own. Either way, I'm here now and I don't know what to do. The crankshaft and the camshaft for 456 are both at TDC. I saw videos of people removing the head for 123 to replace a head gasket and while they were in there, they cleaned up the inside and adjusted valves and so on and so forth. So, I loosened all the valves, took off the rocker arms, and removed the camshaft sprocket/pulley (which word is correct?) for 123. I removed the end cap for the camshaft and pulled the camshaft out and inspected it for damage, looks good. I placed it back in and reattached the sprocket/pulley. I rotated the camshaft so that the mark on the sprocket/pulley lined up with the mark on the engine...TDC. I replaced the rocker arms. I am now attempting to readjust the valves. Here's the problem I am now having...piston 1 was all the way up so in order to not bang the valves against it I rotated the crankshaft 1/4 turn clockwise (no belt attached). Piston 1 obliged and got out of the way. Now I realize that the pulley/sprocket for 123 does not have the cylinder numbers on it like the pulley/sprocket for 456. I still need to have the camshaft rotated to the appropriate position to adjust valve lash, yes? Meaning, to adjust valve lash for cylinder 2 - I would need to have the camshaft in the position it would be in as if I were rotating everything normally, with the belt attached, and the pulley on 456 telling me I'm on piston 2. I know you can realize I'm in over my head now but it's either this or it gets junked, we're past the point of intimidation. How do I tell when it's time to adjust valves for cylinder 1 versus 2 and 3?
 
  #23  
Old 06-03-2024, 03:16 PM
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Wait...am I being real dumb about this? All 3 are now in TDC...I can now place the new timing belt and then adjust the valves with it attached, correct? I think that's right.
 
  #24  
Old 06-03-2024, 04:12 PM
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If you are in time, then you can adjust the valves. Just keep checking that you are in time. You can also look at the egg shaped cam lobes as you move along. If the short end is pointing towards the rocker arm, then that valve should be closed regardless if you are in or out of time. You'd also know something is wrong as the valve gap would be very tight if the valve was being pushed down by the cam lobes. The cam lobes may be hard to see just looking at your pictures.
 
  #25  
Old 06-04-2024, 05:26 AM
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You said I'd know something was wrong as the valve gap would be very tight if the valve was being pushed down by the cam lobes...I did find that there were some valves, I think over cylinder 2, that were still tight even though I had loosened them all as much as I could. I can't infer what you're saying might be wrong though. I've been talking to a buddy of mine about this stuff too, more mechanically inclined than me. He recommended I put something long and metal down in the spark plug hole and crank the engine. Watch the thing move and ensure the piston goes through all 4 strokes, to ensure that the crank is in TDC. So I attempted to do this and was unable to continue cranking the engine manually. It went about a half turn further. I didn't want to ape on it. From what I understand, I should be able to turn and turn and turn this crankshaft without any problems, and if I can't, there's a problem. Forgot to mention - I loosened all the valves on 456 side also to make sure I wouldn't ding any of them while cranking the engine without the belt attached. So....pull the head for 123 side, look at the cylinders?
 
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