Rinker 342 6.2 engine won't start

brandonmayberry

last weekend the port engine died when backing into the slip and then wouldn't start without advancing the throttle. I replaced the IAC and it seemed fine. Now (and I think the issues are unrelated to one another) we were coming back from a weekend outing and the boat was running fine.

 Port motor was around 150temp and oil pressure looked good when all of a sudden the motor just died and fell flat on its face. No stutter or sputter. I tried to start it back up and it just cranks over. 

I felt both risers and they seemed hot (couldn't hold hand on them) compared to the other engine so I turned the key back on and the temp gauge jumped from 150 to about 180. 

I just put new impellers in both motors last weekend. 

I went ahead and pulled the port motor impeller, looked fine. Engine cooled off, tried to start and still won't fire. A gentleman on my dock handed me some starting fluid and I gave it a small shot and the engine then "popped" like it kinda tried to start. He thinks it's fuel related.

I listened to both port and starboard fuel pumps when I turn the key. Both make noise but the starboard is a quiet hum whereas the port is much louder. It still makes noise like its pressurizing so I'm not sure if that would be a culprit or not. Also how would that explain the temperature rising on that engine. The guy on my dock said if it were starving for fuel it may cause it to run hotter.

I wont be back to the boat to hook up my fuel pressure gauge for a few weeks and just wanted to get people's thoughts before hand so I'll be able to bring any diagnostic tools with me that I may need.

The engine oil on the dipstick looked fine also, not watery or milky at all. 

Thanks for any help! 


 

reneechris14

I think your right fuel pump,mpi should 43psi.temperature rising could be just because she shut down quickly,150 to 180 because water stopped  flowing.

brandonmayberry

That is what i was leaning towards but havent dealt with this issue before. I appreciate your input.

Any body have any idea how hard it is to change out the fuel pump on the port side engine of a 342?

Liberty44140

Simple stuff up to date like fuel filters and spark plugs? 

brandonmayberry

Fuel filters didnt get changed yet this year, they were changed at the beginning of last season. Plugs are all good, wires are good also.

Stodge

I found out the hard way that there are 2 fuel pumps on my Merc 5.7s.  One on the front/top the other by the oil pan on the bottom.  Guess which one failed?  I watched my mechanic replace the lower pump, which he did laying across the engine blindly reaching and working.  Much swearing later and it was done.  The 6.2 may have a similar issue.

brandonmayberry

Mine appears to only have one fuel pump but it is under the engine and in the hardest spot to get to. I replaced the one on my 350 mag and it sucked. I assume this will be a similar process. 

212rowboat

the excessive heat could correlate to a lack of fuel circumstance due to leaning out- lean is considerably hotter than rich.  if you were pulling some RPM's when it died, and under considerable load, it could certainly fall on its face as you described.  fuel pressure on a MPI is too easy not to check- simply get the gauge from an auto parts store, and attach it to the port on the rail.  the pressure should maintain a constant across whatever range- from idle to wide open.  you may find your pressure is good low or even at key-on, but when demand for volume at the same pressure increases with RPM's/load, it doesn't have enough. 

if it won't start, first thing is check your present codes- maybe it's trying to tell you something?  What kind of beeps are you hearing if any? cross examine the chart sticky'd to this forum to track down correlating the beep code to the fault. 

if no codes are present you're gonna have to do this the old fashioned way and t/s properly.  
AIR-is the air duct clear of debris? Is there a massive vacuum leak somewhere? is there anything obstructing your exhaust?
Fire- easy enough: in a fume free engine hold, pull the boot off a plug and lay it against the riser- turn engine over and see if there is spark arcing.  
Fuel- do the pressure test... 

brandonmayberry

I'm headed down this weekend to check codes and everything. The engines beep alarm system was disabled by the PO. I need to get it set back up but haven't got around to see how he actually disabled it so I can fix it. I'll check fuel pressure first and for spark of fuel appears ok. Thanks for the comments. 

brandonmayberry

Well I checked fuel pressure and it was good. So I checked spark and wasn't gettin. Any spark to the plugs but cool was sending spark. Swapped cap and rotor from one engine to the other and it fired up. Bought a new set and it's as good as new! Thanks for all the help. I'm excited I don't have to change that dang fuel pump! 

Liberty44140

That's great! Amazing how many issues seem to be solved on this forum with filters, plugs, wires, caps and rotors. 

randy56

Good news, easy fix, are people boating at the lake yet?

brandonmayberry

randy56 said:

Good news, easy fix, are people boating at the lake yet?

Yea there's a good handful of people boating. Weather was nearing 70 yesterday and higher today. Been really windy thou so that keeps a few people from going out. A lot of dock party's. 

randy56

Hey, Hey, right on to the dock party's, a bad day at the lake is much better than a good day at work! Did ya get a chance to make a test run? 

brandonmayberry

Didn't get to make a test run since fixing the issue.