Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? - ZR-1 Net Registry Forums

HB ZR-1 · 06-03-2011

Any thoughts on what the problem is ?? The car idles great and rev's fine in neutral..But once i put it in gear and begin to drive it intermittently hesitates/sputters and the exhaust sounds muffled. 1995 ZR1 59k Original Plug wires and probably plugs.Just noticed it today after being in the garage for three months. Help

ittlfly · 06-03-2011

Any codes? Where in Calif are you?

HB ZR-1 · 06-03-2011

I will look tonight. Huntington Beach. I got new plugs and wires. I will the plugs first as the wires look like a nightmare :0

Kevin · 06-03-2011

Quote:

Originally Posted by HB ZR-1

I will look tonight. Huntington Beach. I got new plugs and wires. I will the plugs first as the wires look like a nightmare :0

i take it you've never pulled the plenum...it's not hard at all

HB ZR-1 · 06-04-2011

Quote:

Originally Posted by Kevin

i take it you've never pulled the plenum...it's not hard at all

I had it off when i first bought it in 2000 to fix a vacuum issue and tied the vacuum endpoints. I have not taken it off myself though. I will have to make a list and make the best of it when it comes off next. Who is porting and polishing plenums these days? Last i inquired Doug Rippie was doing it but last i heard he sold off his inventory.

tomtom72 · 06-04-2011

To your P&P question: Corey Henderson in TX, Marc Haibeck in IL, Mike @ EES in LA, LOCOBOB ( bob Melbo see Dynomite Heads thread here), Lagaf ( Lee in IL a member here ) I know I left out some people, oh jez Pete from IL a member here.

Welcome to our corner of the asylum!

Jerry's Gaskets or White Racing Products will have all you need to do this yourself on the plenum pull if it needs to go that far. Both of those guys are members here and Jerry is our VP.

On this issue. It free revs fine, hot or cold or both? I'd pull the plugs for a look see and when was the last time the fuel filter was looked after? Also, the PCV valves are okay, not stuck shut? Your air duct from the filter housing to the air horn could be getting sucked shut if the choking happens say above 4-5 k rpms.

On this air duct thing, I've never had it happen to me so I'm not up on the symptoms. I ran across the issue in the "common Issues" section over at the NetReg site under the maintenance tab. I made my own duct liner from some dryer duct when I first got my car. I'm thinking that you might have to rev her up almost to 6 or 7 grand in neutral to see it happen, as I would think it more likely to happen under load? I think you ca get replica ducts from corvette central or check with Jerry's Gaskets.

Tom

Kevin · 06-04-2011

ask Keith what a collapsing duct feels like....

06-03-2011	#1
HB ZR-1 Join Date: Dec 2008 Location: California Posts: 5	Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? Any thoughts on what the problem is ?? The car idles great and rev's fine in neutral..But once i put it in gear and begin to drive it intermittently hesitates/sputters and the exhaust sounds muffled. 1995 ZR1 59k Original Plug wires and probably plugs.Just noticed it today after being in the garage for three months. Help Last edited by HB ZR-1; 06-03-2011 at 08:33 PM.

06-03-2011	#2
ittlfly Join Date: Jul 2009 Location: Redding Calif Posts: 223	Re: Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? Any codes? Where in Calif are you? __________________ 1994 ZR-1 # 0102...SOLD

06-03-2011	#3
HB ZR-1 Join Date: Dec 2008 Location: California Posts: 5	Re: Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? I will look tonight. Huntington Beach. I got new plugs and wires. I will the plugs first as the wires look like a nightmare :0

06-04-2011	#6
tomtom72 Join Date: Dec 2004 Location: Jacksonville, FL USA Posts: 4,645	Re: Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? To your P&P question: Corey Henderson in TX, Marc Haibeck in IL, Mike @ EES in LA, LOCOBOB ( bob Melbo see Dynomite Heads thread here), Lagaf ( Lee in IL a member here ) I know I left out some people, oh jez Pete from IL a member here. Welcome to our corner of the asylum! Jerry's Gaskets or White Racing Products will have all you need to do this yourself on the plenum pull if it needs to go that far. Both of those guys are members here and Jerry is our VP. On this issue. It free revs fine, hot or cold or both? I'd pull the plugs for a look see and when was the last time the fuel filter was looked after? Also, the PCV valves are okay, not stuck shut? Your air duct from the filter housing to the air horn could be getting sucked shut if the choking happens say above 4-5 k rpms. On this air duct thing, I've never had it happen to me so I'm not up on the symptoms. I ran across the issue in the "common Issues" section over at the NetReg site under the maintenance tab. I made my own duct liner from some dryer duct when I first got my car. I'm thinking that you might have to rev her up almost to 6 or 7 grand in neutral to see it happen, as I would think it more likely to happen under load? I think you ca get replica ducts from corvette central or check with Jerry's Gaskets. Tom __________________ 1990 ZR-1, Black/grey, #2233, stock. ZR-1 Net Reg Founding Member #316 & NCM member

06-04-2011	#7
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	Re: Car is sputtering & hesitating under acceleration..Exhaust sounds muffled?? ask Keith what a collapsing duct feels like.... __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"