Car is sputtering & hesitating under acceleration..Exhaust sounds muffled??

[HB ZR-1]

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]

Any codes? Where in Calif are you?

[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

[Kevin]

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]

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]

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.

:handshak: 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.

:cheers:
Tom

[Paul Workman]

On this air duct thing, I've never had it happen to me so I'm not up on the symptoms.

Tom

Hey Tom!

I kin hep... Misfiring was not the issue resulting from the snorkel collapsing at WOT, but suddenly bogging (like someone just dropped an anchor out the back) is more like it.

Note: Marc has handy-dandy lil wire hoops that fit inside the accordion-like snorkel tube to keep it from collapsing. But, what I did was similar to your solution - I made a sleeve our of 18(?) ga aluminum sheet metal that slips (snuggly) inside the snorkel - actually extends under the lip of the filter box opening and is anchored there.

The sleeve method frustrates removing and reinstalling the snorkel a bit, due to its rigidity. But, considering how some people feel hogging out the air horn promotes performance, but ignoring the air flow in the un-sleeved snorkel preceding it...seems (to me) to be like removing only one (of the smaller) resistors in series!? Just a thought.

P.

[Kevin]

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