Very big improvement in Idel and Crank from two small changes?

So I did a little work to the truck (2 small changes) and noticed an immediate change in cranking power and engine idle and accel smoothness. Crank has always been a bit hesitant and weak and idle has been a little on the rough side. Nothing that would cause alarm; I just figured it’s a truck and not a Mercedes.

But now it cranks strong and idles so smooth. It’s not my imagination, this is a huge difference. Not exactly a Mercedes, but at least a Camry

I don't know which one of these would make such a big difference but here is what I did

First: Changed my negative terminal lead to the body ground from 8ga to 4ga. The original lead was shit. In fact it was more than shit. I used the 8ga to replace when I first bought it as I was told it should be plenty. As Im adding new electrical draws, I figured I should go ahead and change to a 4ga. Could this be why its cranking stronger? Could the 8ga really make that much of a difference?

Second: Hooked up my oil catch can (vented can and capped the PCV return fitting on the intake manifold). When I changed my intake manifold about a month ago, the old manifold was coatedand dripping of oil from a bad PCV valve. I didnt change the valve but cleaned it with gunk remover spray. Could be why its idling and running smoother? Ive never heard of any differences when adding a catch can...

I’m baffled by the sudden and very noticeable change and I’m very curious why the difference.

 

You removed the blow-by pressure, from behind the piston. The engine isn't fighting it anymore.
When you pressurized the intake, with the turbo, the PCV system doesn't work anymore.

 

Never heard of any noticable gain/diff with a catch can

Im not routing the catch can back to the manifold, Im venting it under the hood and clamped a vacuum cap on the manifold fitting to insure I dont have back pressure going into the crank (and Im not turbo'ed yet, probably by 2020 at the rate Im going now )

 

Prob has a lot to do with cleaning pcv. That's a key part for engine idle. Also these trucks need consistent voltage. Maybe that helped also.

 

Yea... I missed that, at the end of his post. A dirty PCV valve=constant vacuum leak. That would cause a rough idle.
A corroded cable/bad connection to the starter/battery will cause slow cranking.
I need to slow my reading in the morning, without caffination.

 

Happens to me too! Find myself editing when I can.

 

Well looks like it was my lucky day and I fixed two problems I didn't even know I had

PCV valve still needs to be replaced but the catch can effectively removes that out of the equation.

 

I really need to upgrade my cables and clean all ground connections. My cranking has been slightly weaker recently. May also solve my hot start problem. Any idea on where all of the ground connections are? Like engine block ground etc...

 

I too cleaned my PCV and got a little better idle, will wrk on cleaning all grounds and replacing needed wiring. Thanks for this post.
AND NEVER OPERATE WITHOUT CAFFINE. ,,,,, it has bad side effects.