new 5.7 block backfire's after 2500 rpm??

[chrisJet]

I put a new block in just over the past month.. everything runs great on the trailer but once im in the water and hit 2500 rpm it has a backfire and the rpm drops.. I replaced all the ignition components, you name it.. its a 2005 marine power with with a new marine vortec block .. got tired of the headache so I took it to tige.. they think its distributer but its brand spanking new.. it was doing the exact same thing with the old distributer that was out of the old block.. is there anything else possibly? sensor's on the throttle body or anything?? Im running out of ideas and want this damn think done. thanks.

[Chads972150]

could be the coil sending fire to the distributor im not sure if its seporate from the cap in your case or on top of it. could be a sensor but i would think it would do it all the time not just above a certain rpm or in VS out of water could be a bad injector also not being able to deliver fuel under load?

[chrisJet]

I put a new coil in there.. she has spark.. I thought injectors too but its at tige now and its not giving any codes for that.. what sensor could it be? marine power tells me there is none but there has to be.. I would think something is there with the air fuel mix or what not.. tige thinks its the wrong distributor but I had the old one in there also and it did the same thing and they look identical.. they had to call tige on sat but have not heard back yet..

[Chads972150]

my guess would be trottle position sensor not telling the motor to feed more fuel i really beileve its fuel related thats what it only happens at higher RPMS and under load from what it sounds like.

[chrisJet]

ill call and get one of them tomorrow! would that put off a code if that was the problem?

[boatwakes]

I responded to your other post. Turn the distributor clockwise until you can't. Read the other post for full explanation.

[boatwakes]

No codes will be thrown.

[Chads972150]

Boat works makes since I forget about computer timing with these motors it doesn't come to mind unless it's in a dragster with msd ignition or a new fangled one with coil over plug motors I'm thinking mechanical distributor.... That if the timing is off up high it will be off to a point down low too