my buddy just got a 1997 31 sonic with 502 efis and ever since he blew a water impeller when he idles for a extended period of time the 1 or at times both motors will shut down and barley idle wont rev up till they cool down, then runs ok while running the boat on plane or even wide open throttle,it acts like it is vapor locking only when ideling a period of time so my question is does this set up have a fuel cooler that may be partialy plugged from rubber impeller blowing apart restricting the water flow to it at idle when the water pressure is lower and heating up the fuel and vapor locking. this set up does not have a electric pump so if it has a cooler where is it.

thanks

There is most likely a restriction or blockage from the impeller pieces. You must remove all hoses and check each cooler for rubber chunks. Trust me when I tell you that backflushing will not get them all out. Been there many times.

so then there is a cooler for fuel on this set up ?

if you want to find out if it is a fuel temp problem just run with the hatch propped open a few inches on a piece of 2x4. that will get the temps down immediatly and tell you everything you want to know about THAT possible problem. under normal circumstances a vapor lock or fuel temp issue will go away when the motor is running as the new fuel introduced into the system is sufficiently cool enough to not be full of air. i don't think that system has a fuel cooler unless aftermarket.

IT APPEARS THAT THERE IS NO FUEL COOLERS ON THIS SET UP SO THE IMPELLAR PROBALY HAS NOTHING TO DO WITH THE PROBLEM, HERE IS WHAT IT DOES, 3 TIMES AFTER IDLING OUT OF A NO WAKE ZONE ABOUT 5 MINUTES OR SO TO GET OUT, THE DRIVERSIDE MOTOR WHEN TRYING TO TAKE OFF AT ABOUT 3000 RPMS WOULD SHUT DOWN , WHEN TRYING TO RESTART IT IT WOULD START HARD AND IDLE BUT TAKE NO THROTTLE AT ALL AND EVEN SHUT DOWN IDELING AT TIMES, AFTER ABOUT 10 MINUTES OR SO IT WOULD FINALY START AND RUN FINE WITH NO PROBLEMS AT ALL WHEN RUNNING ON PLANE OR EVEN WOT. THE 4TH TIME IDELING OUT HAD THE SAME THING HAPPEN TO BOTH MOTORS AND THAT IS WHAT PUZZELS ME TO THE POINT THAT IT CANT BE MOTOR RELATED WITH BOTH DOING SAME THING ACTING LIKE A VAPOR LOCK PROBLEM.

Anyone Any Ideas

anyone had any simular problems before

Single fuel tank??????

I would change the water sep filters and dump each one into a glass and look for water.

Another thing could be something in the tank creating an obstruction at the pick up.

had the boat back out today after changing fuel / water sep filters, the other motor that has only done it once before did same thing today, go to take off shuts off then starts hard and only idles then stalls, does this for 5 -10 minutes of restarting then will be ok. i know the idle air control motors need cleaned but that should not cause the problem it is having they normaly just cause a stall from time to time witch it does but restarts back up and runs ok .

ANYONE ANY IDEAS

check the pickups. may have crap in the anti-siphon valve.