engine trouble 4.3L

[2005_chap_270]

i have a 2005 chaparral 270 signature with twin 4.3L V6's. About 100 hours on the engines.

Recently the port motor has been giving me troubles. Here is the summary.

When cold, the engine starts and runs fine. I start it, head for our favorite cove (5- 15 minutes at 4K RPM) all is fine. Anchor down and float, eat, drink for 45 minutes to 3 hours and when we get ready to leave the motor will start,,,, but only run for about 3 - 5 seconds, very rough then it dies and will not start again. Have to limp home on one engine?

My mechanic has already changed the cap and rotor as well as spark plugs. Also had the fuel filters replaced. Same problem?

Suggestions?

 

[Chris]

Hi Chap,

Welcome to the forums - nice to have you here.

Is it a carb motor or EFI?

-Chris

 

[RNC]

Hi Chap,



Is it a carb motor or EFI?

-Chris

Need to know this

 

[2005_chap_270]

No carbs -- EFI

 

[Chris]

Well if it's EFI your mechanic might be able to scan it for error codes.

I'm not sure if he tried that yet or not.

It could be a sensor on the way out or defective.

-Chris

 

[Fun Times]

Are any warning horns going off? have you tryd moving the throttle up slowly all the way up too 100% [WOT]? Then after that try pumping it a bunch of times like the old days to see if it will catch and fire off while cranking. When you got home did you try to start it just to see if it will start? Just so you know by giving it throttle you are helping the engine by pass the IAC sensor [motor] and giving it more air and some times that will help in testing and get it started, And Also once you go past a certin % of throttle and it varrys by engine, But once you get to say 50% or 75% or 100% throttle while cranking you are turning off the fuel injectors as long as you are in the right % range, And they do this just in case the engine is getting flooded out for some reason, It would help try to burn the fuel by not adding any more fuel and letting in more air to try to start it up.