Johnson 4stroke 70hp wont take the gas

Frankhanhart

Petty Officer 1st Class
Joined
Dec 30, 2004
Messages
326
Hello gentlemen,
my Johnson 70 ser# BJ70PL4ST(disguised Suzuki DF70) ran fine untill last monday. When applying WOT she stalls and struggles and won't put on revs. When slowly putting on the gas, she reluctantly increases revs up till abt. 5800. The mechanic put her on the diagnostics-machine and could find any electronic failure. So he ruled out an electronic problem. He changed the HPfilter, no change, he had the injectors tested, worked fine. He put in new plugs and hooked the motor up on fresh gasoline to rule out bad fuel from the tank. Now he wants to replace the HPfuelpump in the vapor-separator to see if that gives any solution. When spraying fuel into the air-intake she runs definately better. So he gathers it must be a fuel-problem. I think he's right. But we could be wrong of course. I've been thinking about a code 31 IAC (idle air control valve) problem I had last year. But the code doesn't show up now. Could it be the culprit anyway? Or does anybody have another idea? Thanks Frank
 

Frankhanhart

Petty Officer 1st Class
Joined
Dec 30, 2004
Messages
326
Hello Boobie,
He did, should be 46 psi if I remember correctly and gave a reading of 40 psi. I have no idea what the impact of lacking 6psi might be. Whether it warrants a replacement or not....I have no idea. Thanks for yr interest. Frank
 
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