I know the topic of rough idle has been discussed manytimes, but not often on LS1's. My engine internals are stock. SLP lid, exhaust. I recently changed plugs, it ran better for the next few weeks. A vacuum leak was plugged. I think it was the main vacuum line in front of the manifold pass. side (duct tape). It runs fine cold. Once warmed up, it idles rough & hesitates from a stop. Once the RPMs get over 1000-1200, it runs fine. Fuel filter was replaced not long ago. Please help, my baby is hurting

 

Are you saying you fixed the vacuum leak w/ duct tape?

 

Yes, until I can get a new hose. The rough idle & hesitation still happening.

 

I think the new hose will fix the problem. Doesn't sound like you did anything else to cause that idling issue. Most of the time a mild to bad vacuum leak will cause those problems.

When will you be getting the new hose?

If you could wrap a piece of hose around the leak, and then tape over that w/ the duct tape, it may help until you get the new piece. Let us know what happens.

 

There is no more leak b/c of the duct tape. I plan on getting a new hose when I figure out what the particular piece is called. ??? Any thoughts?

 

sorry but duct might work for now but get the hose and c how that treats ya

 

What kind of plugs did you replace w/?

My dumbarse replaced plugs w/ bosch platnums on my last car and it ran like CRAP!

Which side of the intake is the hose in question located? And how big is it?

 

Do you have a K&N? If so and you over oiled it, you will get the filament on the MAF sensor gummed up and it will hesitate off the line and when you get on it.

You can get some MAF cleaner from any auto parts store and clean the filaments. I had the same problem and doing a little cleaning of the MAF solved it.

R/

Frat

 

AC delco plugs.

The hose turned out to be the PCV hose that connected the main hose to the manifold. replaced.

The roughness turned out to be a loose plug wire. Run perfectly now.

 

Thanks for the tip, but I haven't reoiled the filter in a yr. Not having any problems now. Even the SES is gone.

 

Get it scanned.
It can show you history and everything else.

 

I did get it scanned. It mostly showed the issue w/ the loose plug wire. 1 code showed it runing lean, 1 code showed it running rich, 1 code showed a bad port something. I not worried, SES is gone.