Rough Idle??????

2.4LZ24 · #1 06-30-2006, 08:59 AM

My 99 cav Z24 just started to idle rough today but no engine light came on, What are the causes and how could if fix it? thanks.

VKZ24 · #2 06-30-2006, 12:20 PM

Quote:

Originally Posted by 2.4LZ24

My 99 cav Z24 just started to idle rough today but no engine light came on, What are the causes and how could if fix it? thanks.

First thing I would check is the 2" long hose on the TB that connects to the MAP. Mine had a hole in it a caused a bad idle. Next the TPS sensor if the hose is OK. Third the ignition coils under the IDI cover.

Iboc_C64 · #3 06-30-2006, 01:43 PM

You may not set a code immediately, It may have to run or idle for a while, mine didn't set any codes when I had a bad coil for the first week or so.

VKZ24 · #4 06-30-2006, 01:50 PM

Quote:

Originally Posted by Iboc_C64

You may not set a code immediately, It may have to run or idle for a while, mine didn't set any codes when I had a bad coil for the first week or so.

In my experience the CEL isn't worth crap for engine problems. All it pretty much does is monitor the emissions stuff.

Iboc_C64 · #5 06-30-2006, 02:25 PM

Pretty much, you cant rely on a CEL for diagnosing or for even determining that you even have a problem. I have seen people try to sell 2.4s with a terrble rod knock by saying "Its noisy, but it doesnt set a check engine light so it must be fine" yeah, bullshit.

2.4LZ24 · #6 06-30-2006, 08:00 PM

I checked that hose, its pretty dry rotted, I went to the dealer and it was $30.00, for that little hose, I couldent believe it. I got one on order now anyway, its going to take a couple of days for it to come in. Plugs were fine, coils are fine, everything looks pretty good except for that hose.

MidniteXVZ · #7 06-30-2006, 08:08 PM

OMG you could have picked up 5 feet of vacuume hose for like 10 bucks at napa! YIKES just tell em its for s BBC or similar heh

misnblu · #8 07-03-2006, 01:57 PM

Quote:

Originally Posted by MidniteXVZ

OMG you could have picked up 5 feet of vacuume hose for like 10 bucks at napa! YIKES just tell em its for s BBC or similar heh

I had to do the same this weekend.
The hose was completely dry rotted but still sealed.
I replaced it with some vacuum hose and all is good in the land of GM.
To pay that much for a prebent hose is just too much.

Make it custom and it's usually cheaper.

Misnblu