'95 Caprice LT1 idling rough after plug change?

Erik the Red · 05-30-2012, 03:20 AM

Hello,

I have a '95 Caprice with a LT1 and it just turned 80,000 miles. At 80,000 I change the Spark Plugs to AC Delco Platinums and had the Transmission Flushed and Serviced. After doing this to it, it has developed a rough idle. The car has always idled so smooth, so this was a big surprise. It seems to idle worse when its in gear. It has plenty of power and doesn't hesitate at all. It just runs rough at idle. All the plugs were gaped 0.050". There are no check engine lights on. I'm really confused here....

Thanks,
Erik

**Dwayne J** · 05-30-2012, 05:06 AM

Trying to gap platinum plugs is likely to damage the platinum pucks.

I would look for a plug wire problem.

Look underhood in the dark, maybe bring a spray bottle with water to try and induce arcing.
At one point there was a bad batch of Delco plugs out there that leaked combustion pressure and you could see a blue glow underhood around the plugs when running in the dark.

Crime Scene · 05-31-2012, 07:37 PM

+1 with DJ. But also, make sure all your plug wires are where they are suppose to be, and not crossed by accident. Remember, wire boots must click twice.

**Papa D** · 06-01-2012, 05:21 AM

Quote:

Originally Posted by Dwayne J

Trying to gap platinum plugs is likely to damage the platinum pucks.

I would look for a plug wire problem.

Look underhood in the dark, maybe bring a spray bottle with water to try and induce arcing.
At one point there was a bad batch of Delco plugs out there that leaked combustion pressure and you could see a blue glow underhood around the plugs when running in the dark.

Listen to this man.

Quote:

Originally Posted by Crime Scene

+1 with DJ. But also, make sure all your plug wires are where they are suppose to be, and not crossed by accident. Remember, wire boots must click twice.

Also check this out. Crime Scene said exactly what I was going to suggest.

05-30-2012, 03:20 AM	#1 (permalink)
Erik the Red Junior Member Join Date: May 2012 Location: Portland, OR. Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	'95 Caprice LT1 idling rough after plug change? Hello, I have a '95 Caprice with a LT1 and it just turned 80,000 miles. At 80,000 I change the Spark Plugs to AC Delco Platinums and had the Transmission Flushed and Serviced. After doing this to it, it has developed a rough idle. The car has always idled so smooth, so this was a big surprise. It seems to idle worse when its in gear. It has plenty of power and doesn't hesitate at all. It just runs rough at idle. All the plugs were gaped 0.050". There are no check engine lights on. I'm really confused here.... Thanks, Erik

05-30-2012, 05:06 AM	#2 (permalink)
Dwayne J Super Moderator Join Date: Jan 2009 Posts: 2,661 Thanks: 1 Thanked 45 Times in 31 Posts	Trying to gap platinum plugs is likely to damage the platinum pucks. I would look for a plug wire problem. Look underhood in the dark, maybe bring a spray bottle with water to try and induce arcing. At one point there was a bad batch of Delco plugs out there that leaked combustion pressure and you could see a blue glow underhood around the plugs when running in the dark. __________________ Dwayne 96 Caprice with AI 200cc package Best et 11.5 Best MPH 116 Just another taxi

05-31-2012, 07:37 PM	#3 (permalink)
Crime Scene The Unscrupulous Lt. Colonel Join Date: Mar 2011 Posts: 1,068 Thanks: 0 Thanked 13 Times in 11 Posts	+1 with DJ. But also, make sure all your plug wires are where they are suppose to be, and not crossed by accident. Remember, wire boots must click twice. __________________ 2001 Chevy Impala 3.4 - Traded 2004 Chevy Impala 3.4 - Traded 2002 Chevy Impala 3.4 - RIP 1.12.2011/ Ice Storm 1996 Chevy Impala SS - RIP 4.15.2012/ Asswipe 1996 Chevy Impala SS - Current

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