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Rough at low revs under power after washing...

YADA

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G'day everyone. I've got a problem with my 6 cylinder VS.

At Christmas time I degreased my engine and hosed it down, started the engine, revved it a couple of times, and the belt came off. I put the belt back on and now the engine stutters when I start off. Once I get over 60 it drives fine. Acceleration is rough, either gentle or hard at speeds less than 60. Have I wrecked a sensor or something? I can't see any problems.

The last couple of times I started it, it sounded like it did a quiet backfire. The last time I started it from cold it almost flattened the battery.

Any ideas? I live in a fairly remote area, the nearest mechanic is 80 km away...
 

Brett_jjj

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The harmonic balancer might be stuffed if it threw a belt.Id check it while the engine is idling to see if it has a wobble.If it does ,its probably stuffed.Id also remove the belt and try to manipulate the balancer back and forth etc to see if theres any movement at all in it,if there is any, replace it.The balancer has interruptor blades behind it that pass through the CAS (Crank Angle Sensor),and when the balancer gets a wobble, or is just worn out,it can stuff up the signal the CAS is supposed to generate for the ignition system.In extreme cases the interruptor blades can actually hit the CAS and stuff it up.
 
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YADA

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Thanks for the quick reply. I'll do that first thing in the morning. Is it a technical job to replace the CAS or harmonic balancer? I used to do all the work on my old VH. This VS is so different...
 

FstStig

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Going for the HB as well. Replacing them are very easy. Get a breaker bar and i think they are a 19mm Socket put it on the Harmonic Balancer bolt, make sure the break bar is touching the ground. Give the car a few spilt second cranks. DO NOT try and start or leave it cranking. This will crack the Bolt and allows you to undo the bolt. You will most likely need a Harmonic Balancer puller, these are available from Super Cheap Auto or any automotive store for about $50. You will need the biggest one with 3 Jaws.
 

YADA

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Thanks Mumboman. I've been reading a few threads on HB replacement. Thanks again to both of you for your replies.
 

FstStig

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No worries mate, Let us know how you go tomorrow. We are here whenever you need help.
 

YADA

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G'day all. Got an update about the problem.

It turned out to be a dead middle coil pack that was causing the roughness. The mechanic said it probably had nothing to do with cleaning the engine, that was just coincidence. The belt came off at that time by coincidence as well, helped a little by the water. It turned out that the whole idler pulley assembly was stuffed. The actual idler pulley was fine except for the noisy bearing.

The car's still a piece of crap but at least its drivable now. I really, really regret getting rid of my VH...
 
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