MadMick
Cadet
- Joined
- Jul 29, 2012
- Messages
- 23
Completely STUMPED!!
My rank: Newbie (2 years on water)
Engine: Rebuilt LB from ATK - Chevy 4.3 V6
Issue(s):
I ingested water in previous engine (1998 Mercruiser 4.3 V6) and decided it wasn’t worth fixing so bought rebuilt LB. I have spent every spare hour in the last 5 weeks building out the new engine. I stripped parts off my old motor and if they couldn’t be serviced or repaired I replaced with new parts. Believe me when I say I did not skimp or cut corners. If it looked dodgy it got replaced no matter what. I also replaced any/all sensors/sensors on the engine. I didn’t leave any of the old ones on the engine. All this was done under the guidence and watchful eye of experienced boat owners. I have also studied and read extensively all aspects of my task. I’m not saying I didn’t make any mistakes in the build out because I did and fixed all on my journey.
So the big day came to fire up the motor, out of boat, and everything went great. Started up perfectly but ran a little rough. After much adjusting I ended up putting a new Edelbrock 1409 carb on. It made a huge difference. Engine ran great. Had a Merc mechanic do the timing and after dialing it in I installed in my boat. Engine idles at 650/700rpms. Temp is right on at 160+/-
This was when things started to go sideways on me and I starter having the issues listed above. I had other minor issues but fixed all.
What I have done/checked to rectify my current issues:
It appears to me and others that the fuel pump is shutting off shortly after start up. I know that the pump gets Its initial power from the starter and that once running the control of the fuel pump gets handed off to the oil pressure sensor or sender.
Could I have installed the incorrect sender/sensor? (Dual instead of single station) If so which one is possibly wrong part? Would a dual station create the issues I’m having?
My confusion stems from what terminology is used for these parts as from my reading it seems that people call the sender the sensor and visa versa so I’m having issues determining which is which. This is also the case when looking at Merc diagrams from different sources.
Any help would be appreciated before I have to hand this project off to a marine mechanic and get hit with more costs. I will also admit that I want to finish this project myself. Yes it’s a pride thing at this stage.
My rank: Newbie (2 years on water)
Engine: Rebuilt LB from ATK - Chevy 4.3 V6
Issue(s):
- Stalls approx 2 or 3 min after start - (I believe the fuel pump shuts off) - starts right up after every stall. RPMs at idle 650 to 700. Seems to stall at temp of 120 or above.
- Oil pressure registers 80psi at idle - previous engine always registered 40psi or there abouts at idle and at higher RPMs - (installed new oil pressure sensor, new oil sender, new oil filter, new oil/water separator
I ingested water in previous engine (1998 Mercruiser 4.3 V6) and decided it wasn’t worth fixing so bought rebuilt LB. I have spent every spare hour in the last 5 weeks building out the new engine. I stripped parts off my old motor and if they couldn’t be serviced or repaired I replaced with new parts. Believe me when I say I did not skimp or cut corners. If it looked dodgy it got replaced no matter what. I also replaced any/all sensors/sensors on the engine. I didn’t leave any of the old ones on the engine. All this was done under the guidence and watchful eye of experienced boat owners. I have also studied and read extensively all aspects of my task. I’m not saying I didn’t make any mistakes in the build out because I did and fixed all on my journey.
So the big day came to fire up the motor, out of boat, and everything went great. Started up perfectly but ran a little rough. After much adjusting I ended up putting a new Edelbrock 1409 carb on. It made a huge difference. Engine ran great. Had a Merc mechanic do the timing and after dialing it in I installed in my boat. Engine idles at 650/700rpms. Temp is right on at 160+/-
This was when things started to go sideways on me and I starter having the issues listed above. I had other minor issues but fixed all.
What I have done/checked to rectify my current issues:
- Confirmed fuel pump works
- Confirmed no blockage in fuel lines from bottom of gas tank syphon to the carb.
- Confirmed & tested wiring connections from starter to fuel pump were good.
- Confirmed all grounds were good.
It appears to me and others that the fuel pump is shutting off shortly after start up. I know that the pump gets Its initial power from the starter and that once running the control of the fuel pump gets handed off to the oil pressure sensor or sender.
Could I have installed the incorrect sender/sensor? (Dual instead of single station) If so which one is possibly wrong part? Would a dual station create the issues I’m having?
My confusion stems from what terminology is used for these parts as from my reading it seems that people call the sender the sensor and visa versa so I’m having issues determining which is which. This is also the case when looking at Merc diagrams from different sources.
Any help would be appreciated before I have to hand this project off to a marine mechanic and get hit with more costs. I will also admit that I want to finish this project myself. Yes it’s a pride thing at this stage.
Removed, cleaned and put back in but no change. Thinking I got another dud part. Will pick u new one tomorrow and swap out.