aq130a is it fuel???

[renny1]

1972 volvo aq130a 270 leg
well i was out in the sea today as we now have a bit of a summer here and here is my problem
a WOT she goes well no missing just purring all of a sudden she begins to miss and the rpm gets slower so i back her off and she ticks over as normal leave her ticking over for 20 seconds throttle up "woooosh" she gets there at WOT and stays there for at least a minute then all of a sudden she does it again cough splut and rpm drops
do you think its fuel or not???.... i can rev her whilst in the water and not a cough or splutter to be heard it only happens in gear and plugs are new carbs are clean new condenser,points,dizzy cap.ht leads,new head gasket,new bellows,fresh oil compression 150 148 148 150
im stumped

 

[Don S]

Re: aq130a is it fuel???

http://forums.iboats.com/showthread.php?t=167561

 

[renny1]

Re: aq130a is it fuel???

thanks for that Don S
fuel check done as per Dons guidance and the pressure is fine
looked today and saw the fan belt was as loose as anything(only noticed after boat was out of water) could this affect it in anyway???? what im thinking is spark not being strong enough also noticed the lcd on my vhf radio was barely visible as though it was a dead battery (battery checked and fine) just put the radio on to another battery and the lcd is how it should be, i also changed the plugs again just in case
this problem only happens when engine is warm as i can get out of the harbour from cold and then it happens

 

[Don S]

Re: aq130a is it fuel???

visible as though it was a dead battery (battery checked and fine) just put the radio on to another battery and the lcd is how it should be

How did you test the battery?

If the fan belt was real loose, then you probably weren't charging either.
Tighten (or replace the belt and clean the pulleys if rusty) the belt, charge the battery and give it a test run.

PS: There are no pressure tests in the fuel system tests. All vacuum. IF you actually had pressure, then you were doing something way wrong.

 

[renny1]

Re: aq130a is it fuel???

thanks for the mega quick answer
sorry Don my guage is a pressure and vacum guage so the first word came to head as with the battery my marina has a 2 pronged thingy that goes on the terminals next time out i will replace the belt as it has stretched but if the battery not charging due to the fan belt just slipping would that cause my problem like spark not being strong enough?/?

 

[Don S]

Re: aq130a is it fuel???

When you did those fuel vacuum tests, did you do them on the water while the problem was occuring???

if the battery not charging due to the fan belt just slipping would that cause my problem like spark not being strong enough?/?

It could, fix it and give it a try.

 

[renny1]

Re: aq130a is it fuel???

When you did those fuel vacuum tests, did you do them on the water while the problem was occuring???

yes whilst engine was warmed up and 5 miles out to sea