Engine turned off while running then wont start

[ICohen424]

8.2l Bravo III, was cruising at 40mph today when the port side engine came almost to a stop, was at below 1000 RPM, when trying to put it in Forward or Reverse there was some clunking until it finally just turned off. I limped home with one engine.
At home, I checked every fuse, checked spark, checked for gas at the Schrader valve (dont have a gauge so can't check pressure but it seemed sufficient), switched batteries between port/stbd... but just can't get the port side to start. I can hear the fuel pump prime, the starter has the engine rolling but it just wont start.
Any suggestions?
2019 Chaparral 347SSX

 

[Scott Danforth]

Check for spark

 

[ICohen424]

Check for spark

Yes, checked spark. Spark is perfect.

 

[Scott Danforth]

Yes, checked spark. Spark is perfect.

If you have spark and fuel, then your missing compression or timing

 

[QBhoy]

Tell us more about the clunking ?

 

[ICohen424]

If you have spark and fuel, then your missing compression or timing

Should ignore the message on screen that indicated something about low voltage?

 

[ICohen424]

Tell us more about the clunking ?

It seemed to be that it would clunk when shifting in/out of gear but I was only able to do it a few times until the port side engine stalled.

 

[dubs283]

Yes, checked spark. Spark is perfect.

How did you verify spark?

 

[ICohen424]

How did you verify spark?

Spark plug test light. Only tried one… assumed the others were fine.

 

[Scott Danforth]

Should ignore the message on screen that indicated something about low voltage?

this is the first time you indicate the induction system is EFI

low voltage may mean the injectors are not firing.

It seemed to be that it would clunk when shifting in/out of gear but I was only able to do it a few times until the port side engine stalled.

there should be no clunk when shifting

time to pull the boat and get it on the hard. then pull the drive

 

[ICohen424]

I just got my hands on a fuel injector pump gauge and it’s showering 5psi, even after turning the key on/off (not engine, just power), several times.
I think that means a bad fuel pump. Can anyone confirm if my suspicion is correct?

 

[Bondo]

I just got my hands on a fuel injector pump gauge and it’s showering 5psi, even after turning the key on/off (not engine, just power), several times.
I think that means a bad fuel pump. Can anyone confirm if my suspicion is correct?

Ayuh,...... 5 psi is a carb fuel pressure,..... Efi should be 'bout 40 psi,.....

Before ya start spendin yer money, verify the entire fuel system is Ok, startin' at the tank's dip-tube, the anti-siphon valve on top of the tank, 'n of course, the fuel filter,.....

 

[ICohen424]

Ayuh,...... 5 psi is a carb fuel pressure,..... Efi should be 'bout 40 psi,.....

Before ya start spendin yer money, verify the entire fuel system is Ok, startin' at the tank's dip-tube, the anti-siphon valve on top of the tank, 'n of course, the fuel filter,.....

I’m an old school home garage mechanic type of guy so I don’t know enough about fuel injection. Can I assume that, if the STBD engine works properly and they both share one gas tank, I can skip your suggested steps?
Even with research, I can’t seem to find out how to access the fuel tank.

 

[stresspoint]

i would check the fuel pressure regulator 5 psi means the pump is operating , whether right is another story., you should be able to switch from one motor to the other to test.

 

[ICohen424]

i would check the fuel pressure regulator 5 psi means the pump is operating , whether right is another story., you should be able to switch from one motor to the other to test.

I think you are suggesting to connect the fuel pump from one motor to the other. Without taking it apart and reinstalling it in the other, I dont know how to do so. For that amount of work, Id prefer to bring in a mechanic (unfortunately).

 

[Scott Danforth]

I’m an old school home garage mechanic type of guy so I don’t know enough about fuel injection. Can I assume that, if the STBD engine works properly and they both share one gas tank, I can skip your suggested steps?
Even with research, I can’t seem to find out how to access the fuel tank.

no. with twins, you have two fuel pickup tubes, two anti-siphon valves, etc.

you can not skip any troubleshooting steps.

 

[stresspoint]

I think you are suggesting to connect the fuel pump from one motor to the other. Without taking it apart and reinstalling it in the other, I dont know how to do so. For that amount of work, Id prefer to bring in a mechanic (unfortunately).

no , i am suggesting taking known good parts IE: fuel pressure reg from the working motor and attaching it to the non working one ,its reasonably easy to swap the regulators.you can even do the same with the pump.
grab yourself an online manual if you are unsure of your ability's to put things back together correctly .
avoid the mechanic till you get a idea of what the issue is ,
those guys charge heaps for diagnostics so the more you do yourself the less out of pocket this issue is going to make you.
you have another motor there that you can swap stuff over from for diagnostic purposes , utilize that to your advantage,.

 

[Bondo]

I’m an old school home garage mechanic type of guy so I don’t know enough about fuel injection. Can I assume that, if the STBD engine works properly and they both share one gas tank, I can skip your suggested steps?
Even with research, I can’t seem to find out how to access the fuel tank.

Ayuh,..... Ok,.... Eliminate the tank, hook up a remote can of gas with a piece of 3/8" fuel hose, directly to the filter's inlet fittin',.....
Then retest the pump for pressure,....

 

[ICohen424]

So I figured it out.
Firstly, it’s important to note that I was told by the dealer and as I’ve read that this boat has one tank despite fill locations on both sides.
Additionally, I only have one fuel gauge so the info seemed to logically confirm what I was told and read.
Next, I found a parts list for an earlier model of my boat and saw 2 different tanks and decided my information, despite being given by the dealer, might be wrong.
I grabbed a gas tank, filled it up, and put 3 gal in the port side tank, primed the fuel injector a few times, and it started right up.
Ultimately, like my other problems, I have to find a better source of data or dig further into it myself.

Mostly, thanks very much for all of your responses and advice!!