Popping Sound - ZR-1 Net Registry Forums

Twinmags · 02-05-2007

My '91 Z has a popping sound coming out of the exhaust at idle. I don't have a service manual so I was wondering if anyone could help me out? It is a slight sound and only occurs when engine is warmed up. I am not showing any codes and everything works. It seems as if it is only performing at about 95%. I'd appreciate any help.

Kevin · 02-05-2007

could be leaking injectors. how many miles on the car? stock injectors?

Twinmags · 02-05-2007

They are stock injectors and it only has 28,000 miles.

RICHARD TILL · 02-05-2007

read the plugs yet?

Twinmags · 02-05-2007

Quote:

Originally Posted by RICHARD TILL

read the plugs yet?

This might be a stupid question, but what do you by read the plugs?

DaveK · 02-05-2007

He means have you pulled the spark plugs to see if any is showing signs of fouling etc. which could indicate a cylinder wasn't firing properly or something like that. There's a good explanation here -

http://www.nightrider.com/biketech/spkplghnbook.htm#We

jonszr1 · 02-05-2007

Reading the plugs will give you an Idea of the fuel mixture. what you dont want to see is litle dark specs on the porcelin . that means its detonating . those little specs are little bit of piston. Don't worry to much it sound scarier than it is . Ck your fuel pressure to see if its within spec when you floor it . You can get a gauge with a long enough hose and tape it to the windshield. go find a safe place to get on it have a buddy sit in the passenger seat and read the gauge. i believe it should be between48-55 lbs, but check your manual to be sure. hope that helps.

Twinmags · 02-06-2007

Thanks for all the help guys. I believe the plugs are the cause but I am going to check the rest. Its supposed to get up to 60 degrees today, so the girl and I are going to take Z out for a drink this evening. Thanks again.

ZR1 MK · 02-07-2007

Popping sound is usually an over rich condition. Probably caused by too much fuel, but can be an electric deficiency such as not burning all fuel.
Injector check would be my first priority. Possible small leak from one to a few.

RICHARD TILL · 02-08-2007

meaning if you find a wet plug= Bingo, theres the problem.

02-05-2007	#1
Twinmags Join Date: Feb 2006 Location: Tulsa, OK Posts: 8	Popping Sound My '91 Z has a popping sound coming out of the exhaust at idle. I don't have a service manual so I was wondering if anyone could help me out? It is a slight sound and only occurs when engine is warmed up. I am not showing any codes and everything works. It seems as if it is only performing at about 95%. I'd appreciate any help.

02-05-2007	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,624	Re: Popping Sound could be leaking injectors. how many miles on the car? stock injectors? __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

02-05-2007	#3
Twinmags Join Date: Feb 2006 Location: Tulsa, OK Posts: 8	Re: Popping Sound They are stock injectors and it only has 28,000 miles.

02-05-2007	#4
RICHARD TILL Join Date: Aug 2005 Location: Iuka, Mississippi 38852 Posts: 756	Re: Popping Sound read the plugs yet?

02-05-2007	#6
DaveK Join Date: Jul 2004 Location: Sudbury, Ontario. Canada Posts: 1,537	Re: Popping Sound He means have you pulled the spark plugs to see if any is showing signs of fouling etc. which could indicate a cylinder wasn't firing properly or something like that. There's a good explanation here - http://www.nightrider.com/biketech/spkplghnbook.htm#We __________________ 1991 #1516 Black/Black davidmkelly.com Author of fast-paced, sci-fi thrillers.

02-05-2007	#7
jonszr1 Join Date: Sep 2006 Location: lone pine and mammoth lakes Posts: 1,406	Re: Popping Sound Reading the plugs will give you an Idea of the fuel mixture. what you dont want to see is litle dark specs on the porcelin . that means its detonating . those little specs are little bit of piston. Don't worry to much it sound scarier than it is . Ck your fuel pressure to see if its within spec when you floor it . You can get a gauge with a long enough hose and tape it to the windshield. go find a safe place to get on it have a buddy sit in the passenger seat and read the gauge. i believe it should be between48-55 lbs, but check your manual to be sure. hope that helps.

02-06-2007	#8
Twinmags Join Date: Feb 2006 Location: Tulsa, OK Posts: 8	Re: Popping Sound Thanks for all the help guys. I believe the plugs are the cause but I am going to check the rest. Its supposed to get up to 60 degrees today, so the girl and I are going to take Z out for a drink this evening. Thanks again.

02-07-2007	#9
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 142	Re: Popping Sound Popping sound is usually an over rich condition. Probably caused by too much fuel, but can be an electric deficiency such as not burning all fuel. Injector check would be my first priority. Possible small leak from one to a few.

02-08-2007	#10
RICHARD TILL Join Date: Aug 2005 Location: Iuka, Mississippi 38852 Posts: 756	Re: Popping Sound meaning if you find a wet plug= Bingo, theres the problem.