Sates

I have a generation V 454 wich i have added vortec heads and edelbrock rpm intake. When I rev to 4200 rpm it cuts out like there is a rev limeter or as if its not geting spark and does not want to fire. It does not quit just starts to gargle at 4200. I have new plugs wires cap and roter and coil. Could this be a timing issue? IT runs perfectly till I hit that rpm. I am stumped.

nard

check all your ground wires

p4-33

Are your plug wires cut-to-fit? I had a problem with a new set of wires where one of them (actually two) were not making good contact. Would idle fine, and I could even rev it to set timing. But once I tried to put a load on it, it would cut out and sputtered pretty bad. Double check your crimps.

Brian

Ty Russell

Mine does exactly the same thing at 4400 rpm. It was a 300 hp gen VI 454 that I did some mods on over the winter; edelbrock heads, airgap intake, 502/502 cam and gil exhaust with corsa captains call. It run great but cut out at 4400. it used to run 4700 with no problems. I think it's the stock 750 weber carb is jetted too lean so I spent the last week hooking up a 750 Holley. I will know if that solves the problem tomorrow. Blue Thunder had a similar problem when he build up his 454 and the Holley cured it. I had 3-step metering rods in the weber and they are very hard to find so I just bought the Holley. Just my 2 cents worth. Ty

robyw1

I know the gargle you speak. it is dropping a cylinder but probably the only way to find out which one is to yank a plug wire and run up to 8 tests to see when the gargle does not change. It is difficult to tell any other way because a laser thermometer will not ID a cool exhaust because of the water running through it. I'm betting wire because it is more common to get a bad one than any other secondary ignition component. Take a new wire out with you sometime and keep replacing wires 1 by 1 until it doesn't miss.

Panther

what kind of carb are you running? I ran into a situation a few years ago with a Holley and the secondary needle/seat was clogged. It would cruise perfectly but once you opened the secondaries it would start gargling and popping.

I'd also check the coil, I had one go bad on me last year and the same thing would happen.

I think it's either spark or fuel

JJONES

Has The Boat Been Sitting A While?i Had A Similar Problem But Ended Up Being Bad Gas,it Would Run Ok Unitl I Hit The Throttle Then It Was Dumping Water Contaminated Gas In Under Wot,this Happens Becdause The Fuel Floats On Top Of The Water And The Slow Circuit Is In The Fuel,but At Main Circuit The Carb Is Using Fuel From The Bottom Of Carb Were The Water Is Which Was Causing My Popping,drained The Gas Cleaned The Carb,now Works Great!OH YAH,THIS DOESNT COST ANYTHING!

offthefront

iTrader: (1)

just .02 .... my 454 would backfire at WOT ..5000 .. new plugs ..can of mercury fuel treatment ...quart of MMO in fuel ...and new fuel filters and the problem went away ...`

jboater

I had the same problem, turned out to be a bad coil