SouthernExposure

Hello everyone,

Problem # 1

The problem I'm having is with my 350 Vortec engine installed in 2004. The engine came with everthing installed, Holley Carb, electric fuel pump ...
The problem is once I am on plane as the rpm's get close to 3500-4000 rpm's it starts to lose power and the engine starts to sputter. In the driveway it will turn 5000 rpms' or better. From a dead start wih full throttle it takes off. If I don't pull the throttle back in time it starts to lose power and sputter. Also on that note when the throttle is pulled back quickly you can hear a rush of air (sucking sound). The same sound you would hear if you pulled the air cleaner off and gave it throttle quickly.
The old engine did not have this problem. I could reach somewhere between 4400-4600 rpm's.

Problem # 2

When I am under power above a certain rpm, which I can't remember 2500 rpm I think, when I attempt to trim the boat I lose power. I can see my voltage meter drop. Up or down does this. Of course this did not happen with the other engine.

Lost!!

Thanks in advance.

Tony

Steve H

you definitley have a bad connection on one of your main power feed wire to that engine. I would look at your connections at your starter and battery. Not only should they be clean and tight. They need to be good where the wire meets the connector. You should be able to pull on each these wires, and they should not come off.

Suggestion: Start the troubled engine and start pulling and wiggling wires. (The larger ones near starter and battery) see if you can get the motor to miss by doing that. If it does then you just found your problem.

Steve Hixson

hillbilly24

aslo jiggle the 10 pin connector where the boat harness plugs into the engine harness, it should also have a hose clamp on it, if it sputters when you jiggle it pull it apart and spread the pins out just a little and plug it back in with a hose clamp around it.

Ted G

iTrader: (1)

I suspect you may have a bad power feed to your fuel pump. I have seen fuel pumps that were wired to the positive side of the coil do this. When it gets rolling the coil and the pump draw too much current and one or both start to fail. You shoild have 10 gauge or better wire and a relay feeding the electric pump regardless. And an oil pressure cut off would be a good idea to shut off the pump if the engine is off.

SouthernExposure

Thanks for the info. I'll check it out. The last response just turned on a light in the noggin. My previous engine did not have this problem. It also did not have an electric fuel pump or electric choke. I know that I did not connect the wiring to the coil but I do not remember what I did do. I did not use a relay either. Picked up a couple of relays today. I did fuse it though.

Later

Tony

speedball

if all else fails check your battery switch . I had one go bad and when I hit the trim switch the motor would die

clpbs

Check to make shure the trim is wired to the bettery and not the starter.This will make the engine stumble