arkvet
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- Sep 15, 2014
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Just trying to identify a problem that may be slowly coming on rather than an abrupt failure.
Here are the symptoms: Several months ago (on another thread) I noted how quickly my IO-540 would fire up (1st blade or 2) and would immediately come up to power (according to throttle). The past couple months it's been much more sluggish starting.
My untrained self wants to blame the electric fuel pump and here's why: Previously I noted that when I went through the start-up procedure the fuel flow on the tractor gauge would come up to 6-8 during the (pump on / throttle forward / mixture rich - priming procedure). Of course when throttle and mixture were pulled back the FF would drop back down prior to key turn but it started super fast as if primed well.
Now the FF needle barely lifts off the stop when priming the engine prior to start-up. It does lift but barely.
It may be coincidental but I'm thinking this change for more difficult starts occurred around the time the JPI 830 was installed (which has FF of course). I can't imagine that that install caused any issue but thought I'd at least throw that info out there.
When I startup now it takes several full blade turns before it fires and with appropriate mixture / throttle changes it will barely idle as if it's starving for fuel for about 6-8 seconds then quickly perk up and happily idle. This is what leads me to believe the engine is really starting by priming itself with the engine driven pump and the electric pump isn't doing much.
The engine otherwise seems happy. Runs great. No issues after start-up.
Any thoughts on these symptoms?
Here are the symptoms: Several months ago (on another thread) I noted how quickly my IO-540 would fire up (1st blade or 2) and would immediately come up to power (according to throttle). The past couple months it's been much more sluggish starting.
My untrained self wants to blame the electric fuel pump and here's why: Previously I noted that when I went through the start-up procedure the fuel flow on the tractor gauge would come up to 6-8 during the (pump on / throttle forward / mixture rich - priming procedure). Of course when throttle and mixture were pulled back the FF would drop back down prior to key turn but it started super fast as if primed well.
Now the FF needle barely lifts off the stop when priming the engine prior to start-up. It does lift but barely.
It may be coincidental but I'm thinking this change for more difficult starts occurred around the time the JPI 830 was installed (which has FF of course). I can't imagine that that install caused any issue but thought I'd at least throw that info out there.
When I startup now it takes several full blade turns before it fires and with appropriate mixture / throttle changes it will barely idle as if it's starving for fuel for about 6-8 seconds then quickly perk up and happily idle. This is what leads me to believe the engine is really starting by priming itself with the engine driven pump and the electric pump isn't doing much.
The engine otherwise seems happy. Runs great. No issues after start-up.
Any thoughts on these symptoms?
