4.3 runs well all the time and SUPER sometimes!

[dpastell74]

Recently bought a 98 bayliner with a 4.3 2bbl carb 190hp. Runs well all the time, planes out quick and rpms are 4800. On occassion it will get crazy. Planes out in half the time, bounces the rev limiter at 5100 at 7/8 throttle and gains 5-6 mph. It will do this for only as long as the current key cycle.
Nothing else has changed. Everything is set per fact specs. It has the TB-V ignition without knock sensor. Only thing I can think is a coolant temp sensor with bad readings messing with the timing most all the time and working proper the times it runs Really good. It is a 18 ft bowrider with a 19 pitch. Any thoughts would be great!

 

[Kainon]

Re: 4.3 runs well all the time and SUPER sometimes!

different trim or boat load ? 1/2tank fuel vs full ? 3 people vs 1 ? trimming out a little more than you did before ?

 

[QC]

Re: 4.3 runs well all the time and SUPER sometimes!

Planes out in half the time, bounces the rev limiter at 5100 at 7/8 throttle and gains 5-6 mph. It will do this for only as long as the current key cycle.

Maybe a really good recurring dream during a short nap on the lake?

 

[dpastell74]

Re: 4.3 runs well all the time and SUPER sometimes!

Like I noted before, ONLY thing that changes is shutting down engine and restarting. Fuel level, trim, #of people the same. When it does it, it will run badass for the whole ignition cycle. Shut it off, then back to normal running.