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James Robert

Fast idle 3.4 DOHC

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Is 1500 RPM too high for cold idle on 3.4 DOHC? I really don't like the little rattle I hear for that fraction of a second before oil pressure builds when first starting my car from cold. Is there a way to lower the fast idle?

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9 minutes ago, Psych0matt said:

It idles that high, or gets that high in startup?on cold mine usually drops from 1500 to about 800 over 10 or 15 seconds, it’s normal.

If it stays higher then you might have a vacuum leak (I take gaskets are usually the culprit)

It just seems too eager to fire up. I guess I shouldn't complain, but it just revves right up with a short turn of the key,  and then drops down. I just don't like the fact that the RPMs jump so fast, so soon. I know that's probably normal, but I would prefer a less enthusiastic start, since most bearing wear occurs on initial startup. On my early cars with carbureted automatic chokes, I would crank them for 8-10 seconds before setting the choke, just to build some oil pressure. I still like the idea of an auxiliary electric oil pump, that could be switched on for a few seconds before starting an engine, to prevent dry bearing starts. But then, I digress….

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On 1/14/2019 at 9:22 PM, James Robert said:

On my early cars with carbureted automatic chokes, I would crank them for 8-10 seconds before setting the choke, just to build some oil pressure..

You created a lot of extra wear by grinding on the starter motor without starting the engine.

1.  You added wear to the starter

2.  You added wear to the flywheel ring gear (and the ring gear isn't lubed!)

3.  Cranking the engine added wear to the rings, cylinder walls, bearings, cam 'n' lifters, etc.

It's much better to just start the damned engine and build oil pressure instantly, than to "baby" it while adding extra revolutions.  Certain oils are better than others for remaining on parts while the engine is shut off.  THAT could be worthwhile.

Edited by Schurkey

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On ‎1‎/‎23‎/‎2019 at 6:14 PM, Schurkey said:

You created a lot of extra wear by grinding on the starter motor without starting the engine.

1.  You added wear to the starter

2.  You added wear to the flywheel ring gear (and the ring gear isn't lubed!)

3.  Cranking the engine added wear to the rings, cylinder walls, bearings, cam 'n' lifters, etc.

It's much better to just start the damned engine and build oil pressure instantly, than to "baby" it while adding extra revolutions.  Certain oils are better than others for remaining on parts while the engine is shut off.  THAT could be worthwhile.

I must respectfully disagree.  1. Starter motors are cheap. 2. I've never seen "wear" on a flywheel ring, and 3. cranking does not add wear to rings, cylinder walls, bearings, cam 'n' lifters, etc. But, yes, I've found synthetic oils can reduce wear on cold starts.

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