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blowing fuses

bcclew

Regular Contributor
mercruiser1998 5.7 tbi I had another post on having a bad fuel injector same engine. new prob engine run fine starting it and let it mabe 5 mins. or even 20 mins then blows ing. relay fuse15 amp and also kill fuel pump circuit .put in new fuse and back running again.how long?looking at dia.that is the emc/dlc battery fuse.also new fuel pump. I checked amps when running 7amps. looking at dia. electronic spark control module mabe it can short to ground once in while?any ideas would be great thanks bcclew ps ran fine out on water 3500 rpms 20 mins than blew fuse
 
Fuses blow 'immediately" when there is a "short circuit" i.e., the instantaneous current exceeds the rating by a very large amount. However, if the current exceeds the rating by say 50 to 100%, the fuse may carry that current for a few mins to an hour before blowing. An easy check is feel (carefully) the ign coil... it should be warm but not hot.
 
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Check the wiring for the injectore at the body. One time found some chafed wires causing a short and blowing the same fuse. They go thru a rubber grommet.
 
Sorry to get back so late bt righr on. Gray wire to tbi was rubing hat on blows fuse hat off ran good. Fixed gray wire back in shape thanks for comebacksbcc lew
 
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