2001 volvo 4.3 efi Hesitation

[Tail_Gunner]

Recently i have introduced a 20 pitch 4 blade w/vents to this boat. It came from a factory 19p 3bl Al, the 20 really enhanced the boat's preformance and runs quite well at 4900 rpm.

However i have noticed something new, there is a slight jerk or pull when you acclerate quickly that is slam the throttle. It actually is better described like a 4 barrel carb opening and even sound's like it hmmm the old baaaRooommm..

The motor start's with ease, no idle issue's,maybe a tad heavy on fuel consumption put that as just a guess, the fuel issue that is.

This is the first efi boat ive had so im not sure it this is normal, or being the prop is slightly vented could this be the prop hooking up......... i see two exhaut's port's on this sx drive which makes me wonder if that much exhaust goes thru the hub causing a little cavitation?

It would be simple to go down and let the guy's look at it or hook up a diag comp but im not even sure if that can be done or can a comp on a boat read out what's going on like a car's system can?

 

[Don S]

Re: 2001 volvo 4.3 efi Hesitation

Put your old prop back on and see if it still does it.
Might as well know if it's a prop induced problem or something that accidentally happend at the same time.

 

[Tail_Gunner]

Re: 2001 volvo 4.3 efi Hesitation

No it does not, sorry i guess i could have posted as much, but as usal my mind is caught up in this. The old prop was way under the boat's need's.... ( no heavy loads on the motor)

This new prop has a lot of cupping more blade's which increased the speed by 5mph, the old one would be able to hit the rev limiter quite easy so i guess the load was not as great on the engine aka no bogging when popping it wide open.

There is good balance though @ wot it reaches 4850 to 4900 rpm so i dont think im over propped , I guess im asking, does a sx drive vent a lot of exhaust to the hub which could account for what's happening, or if a efi (tbi) can run, or is running properly will this occur .....or can it run with a bad sensor and not be known by the ignorant operator here,,,,,,,,,,, no idiot light on this boat.....

 

[Don S]

Re: 2001 volvo 4.3 efi Hesitation

There may be a split second lag on the TBI when slamming the throttle open, I have no idea. Never tried it.