jakedaawg
Rear Admiral
- Joined
- Jun 26, 2012
- Messages
- 4,275
E60DPLINC
2012 60hp ETEC
This is on a rental pontoon. Actually, a good friend of mine is the tech on this one. He asked me to post to maybe get a fourth guess.
Issue:
WOT 5800. It hits WOT and will run for a bit nice and smooth. It then drops 1000-1200 rpm and will run for 5-15 seconds nice and smooth and then jump back to WOT. Then after a minute or a few minutes it drops back down again. Will do this over and over. It is a fairly instant drop in rpm and just as instant recovery. It does not spool up or down.
On the way up to WOT you can notice a miss here and there.
At 4400 rpm a miss is constant however slight.
No relevant codes or faults historical or active.
All the stupid stuff we could think of has been checked/ruled out. Plugs, fuel lines/filters, anti-siphon, etc...
So, at first we figured an injector going bad. Did dynamic shut offs while issue was occurring, both spark and dropping an injector. This prooved nothing. We were hoping to determine which cylinder was dropping.
Went on to fuel pressure. All pressure and vacuum readings are in spec. However, with experience and advice from other techs we have learned that circulation pump pressures on the low end can prove problematic. With two different guards we had 26-28 psi at WOT while issue is occurring. Spec is 20-35. Good residual, no bleed down.
All resistance and other checks came in spec with the exception of circulation/high pressure pump ohm reading. Manual specs 3 ohm, this one reads 2 ohm.
Injectors spec at 2.5 ohm.
We even hooked up a timing light on each cylinder hoping we could see something, proved fruitless.
It is as if it just decides to run 46-4800 and then back to 5800, with the exception of the slight yet constant miss if you hold throttle at 4400. I am not sure at which rpm this one changes the charge to stoichiometric, or if that was just in the Vees.
When it first came in he found the three port power head bolts loose or missing. Replaced base gasket and solved that.
We are looking for opinions. Leaning towards throwing a VST assembly at it. Going to check via serial number for any related service bulletins in the AM but thought I would post this up tonight in hopes someone sees it on the way out in the morning.
2012 60hp ETEC
This is on a rental pontoon. Actually, a good friend of mine is the tech on this one. He asked me to post to maybe get a fourth guess.
Issue:
WOT 5800. It hits WOT and will run for a bit nice and smooth. It then drops 1000-1200 rpm and will run for 5-15 seconds nice and smooth and then jump back to WOT. Then after a minute or a few minutes it drops back down again. Will do this over and over. It is a fairly instant drop in rpm and just as instant recovery. It does not spool up or down.
On the way up to WOT you can notice a miss here and there.
At 4400 rpm a miss is constant however slight.
No relevant codes or faults historical or active.
All the stupid stuff we could think of has been checked/ruled out. Plugs, fuel lines/filters, anti-siphon, etc...
So, at first we figured an injector going bad. Did dynamic shut offs while issue was occurring, both spark and dropping an injector. This prooved nothing. We were hoping to determine which cylinder was dropping.
Went on to fuel pressure. All pressure and vacuum readings are in spec. However, with experience and advice from other techs we have learned that circulation pump pressures on the low end can prove problematic. With two different guards we had 26-28 psi at WOT while issue is occurring. Spec is 20-35. Good residual, no bleed down.
All resistance and other checks came in spec with the exception of circulation/high pressure pump ohm reading. Manual specs 3 ohm, this one reads 2 ohm.
Injectors spec at 2.5 ohm.
We even hooked up a timing light on each cylinder hoping we could see something, proved fruitless.
It is as if it just decides to run 46-4800 and then back to 5800, with the exception of the slight yet constant miss if you hold throttle at 4400. I am not sure at which rpm this one changes the charge to stoichiometric, or if that was just in the Vees.
When it first came in he found the three port power head bolts loose or missing. Replaced base gasket and solved that.
We are looking for opinions. Leaning towards throwing a VST assembly at it. Going to check via serial number for any related service bulletins in the AM but thought I would post this up tonight in hopes someone sees it on the way out in the morning.
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