350 OMC gets OP TEMP wants to Die on Throttle?

[Aquadzac Captain]

Ok experts, lets keep this simple? What would cause, TOP 10 THINGS, that would cause a 350 to run great till NORM OP TEMP then wont be able to THROTTLE UP...boggs down to try and cut out? <br /><br />OMC COBRA<br />350 GM<br />new 600CFM eldebrock<br />88 Bayliner Capri 24.5 foot Sunbridge<br />new coil<br />new eletronic ig<br />new Alt

 

[rodbolt]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

test the fuel pressure at the carb inlet and the fuel vacum at the pump inlet. this is after verifying the ign system is working at normal operating temp.vac/pressure gauge is maybe 20 bucks. the Kv tester from snap-on is a bit more.

 

[Striper Blues]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

I had a similar problem on my omc (Ford motor) and it turned out to be the new carb......yup, it was starving the engine for gas. Any popping through the carb when it starts to give you trouble?

 

[Don S]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

Also check for a vacuum leak. When you are running on a cold engine the choke is mostly closed and the air being pulled in from the wrong place will not show up as a real problem till the choke is off.

 

[waterone1@aol.com]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

I'm going to go with Don's suggestion, a vacuum leak. Check the torque on the intake manifold bolts and the carb bolts.

 

[Aquadzac Captain]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

Put a pressure gauge on the fuel line and it started at 5.3 and in 15 minutes went to 3.9 and maybe still dropping? FUEL PUMP??

 

[Aquadzac Captain]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

Put a pressure gauge on the fuel line and it started at 5.3 and in 15 minutes went to 3.9 and maybe still dropping? FUEL PUMP??

 

[Aquadzac Captain]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

30 minutes Fuel Pressure went down 1.9psi. As the motor heats up the pressue goes down? Any thoughts to why? seals in the pump??

 

[rodbolt]

Re: 350 OMC gets OP TEMP wants to Die on Throttle?

use the vacum side to see if as more fuel is being drawn a restriction is reducing the amount of avalible fuel. hook up between the suction side of the pump and the tank. anything more than aabout 4"Hg means you have a restriction. if it cant get it it wont pump it. anything less than about 1"Hg usually indicates an air leak.