Engine cuts in and out
07-29-2017 | 08:22 PM
#17
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Joined: Apr 2014
Posts: 2,345
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So, if I understand correct, above 3500 rpm you can move one drive up/down at a time without the problem? Can you move the other drive by itself up/down without the problem?
Only happens if BOTH drives are moving up/down at the same time?
Regarding the K-Planes can you move both (above 3500 rpm) without problem? Can you move one at a time without a problem.
What I am thinking is the trim and the tabs use the same (meaning identical not physical) pump assemblies and therefore should have the same electrical draw on the system.
Does the boat have Docking Lights? See if turning them on at above 3500 rpm has any effect. Most docking lights have a high electrical demand also.
Hopefully replacing the remaining battery will fix.
Good Luck
Only happens if BOTH drives are moving up/down at the same time?
Regarding the K-Planes can you move both (above 3500 rpm) without problem? Can you move one at a time without a problem.
What I am thinking is the trim and the tabs use the same (meaning identical not physical) pump assemblies and therefore should have the same electrical draw on the system.
Does the boat have Docking Lights? See if turning them on at above 3500 rpm has any effect. Most docking lights have a high electrical demand also.
Hopefully replacing the remaining battery will fix.
Good Luck
07-29-2017 | 09:07 PM
#18
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Joined: Jul 2011
Posts: 9,594
Likes: 46
From: Ft. Worth TX
load test the batteries and what is voltage output when running the engine(s) ? can careless what the volt gauge reads so use a volt meter or you can monitor real accurate voltage outputs with a scan tool plugged in. Trim the engines and watch to see what happens to voltage - My guess is a huge voltage drop. Another reason to own a scan tool. I take it these are MPI engines since you said 502 MAGs ???. But I do realize very early 90s had 502 mag carbs as well.
Voltage drop test thru out the systems and most likely you find the area causing the problem. One starts at the battery then moves on thru out.
R all cable clean and tite with no corrosion and no wig nuts for cable connections to the batteries.
Next areas are -- Loose and or corroded cables at the starter or the back side of alternator and or back side grounds of the engine ? If batteries seem to load test perfect then this is were my guess is - one of these areas. Not uncommon to have heavy corrosion and or loose connections at the starter. I would look there regardless plus the other areas,
Next area tilt and trim power and grounds plus connections tite and no corrosion for any of it ??
Very important info and even more so with MPI marine engines --- loose and or corrosion for wiring / cables and connections and grounds causes electrical resistance = ie higher ohms. AND on top of If batteries are weak this can be a huge voltage drop especially for ignition output and MPI systems.
Lastly -- harness cannon plug loose and or corrosion or wet ?
Voltage drop test thru out the systems and most likely you find the area causing the problem. One starts at the battery then moves on thru out.
R all cable clean and tite with no corrosion and no wig nuts for cable connections to the batteries.
Next areas are -- Loose and or corroded cables at the starter or the back side of alternator and or back side grounds of the engine ? If batteries seem to load test perfect then this is were my guess is - one of these areas. Not uncommon to have heavy corrosion and or loose connections at the starter. I would look there regardless plus the other areas,
Next area tilt and trim power and grounds plus connections tite and no corrosion for any of it ??
Very important info and even more so with MPI marine engines --- loose and or corrosion for wiring / cables and connections and grounds causes electrical resistance = ie higher ohms. AND on top of If batteries are weak this can be a huge voltage drop especially for ignition output and MPI systems.
Lastly -- harness cannon plug loose and or corrosion or wet ?
Last edited by BUP; 07-29-2017 at 09:25 PM.
07-30-2017 | 07:08 AM
#19
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Joined: Jul 2009
Posts: 783
Likes: 51
From: NJ
load test the batteries and what is voltage output when running the engine(s) ? can careless what the volt gauge reads so use a volt meter or you can monitor real accurate voltage outputs with a scan tool plugged in. Trim the engines and watch to see what happens to voltage - My guess is a huge voltage drop. Another reason to own a scan tool. I take it these are MPI engines since you said 502 MAGs ???. But I do realize very early 90s had 502 mag carbs as well.
Voltage drop test thru out the systems and most likely you find the area causing the problem. One starts at the battery then moves on thru out.
R all cable clean and tite with no corrosion and no wig nuts for cable connections to the batteries.
Next areas are -- Loose and or corroded cables at the starter or the back side of alternator and or back side grounds of the engine ? If batteries seem to load test perfect then this is were my guess is - one of these areas. Not uncommon to have heavy corrosion and or loose connections at the starter. I would look there regardless plus the other areas,
Next area tilt and trim power and grounds plus connections tite and no corrosion for any of it ??
Very important info and even more so with MPI marine engines --- loose and or corrosion for wiring / cables and connections and grounds causes electrical resistance = ie higher ohms. AND on top of If batteries are weak this can be a huge voltage drop especially for ignition output and MPI systems.
Lastly -- harness cannon plug loose and or corrosion or wet ?
Voltage drop test thru out the systems and most likely you find the area causing the problem. One starts at the battery then moves on thru out.
R all cable clean and tite with no corrosion and no wig nuts for cable connections to the batteries.
Next areas are -- Loose and or corroded cables at the starter or the back side of alternator and or back side grounds of the engine ? If batteries seem to load test perfect then this is were my guess is - one of these areas. Not uncommon to have heavy corrosion and or loose connections at the starter. I would look there regardless plus the other areas,
Next area tilt and trim power and grounds plus connections tite and no corrosion for any of it ??
Very important info and even more so with MPI marine engines --- loose and or corrosion for wiring / cables and connections and grounds causes electrical resistance = ie higher ohms. AND on top of If batteries are weak this can be a huge voltage drop especially for ignition output and MPI systems.
Lastly -- harness cannon plug loose and or corrosion or wet ?
Thanks for the in detailed help, I will pass it along and make sure everything mentioned is checked
07-30-2017 | 07:17 AM
#20
Registered
Joined: Feb 2012
Posts: 4,031
Likes: 10
From: westville, NJ
the trim pumps have their own hot wire. the load side not the switch side. take a spare battery and run the trim pumps off that battery keeping them separate from rest of electrical system. problem goes away, then the pump or pumps draw too much current. problem still there it is possible something shorting between trim switch wiring and main electrical. likelihood very low on the second though.
