Falling on It's Face - VP501 DPA

[Hook'd]

Folks,

Background which might be relevant...I have what was originally a 501, swapped out with an indmar 5.7. It has a Rochester 17052983, and an electric fuel pump. It has an electronic distributor. It has an engine mount filter, and an added racor. I have a perko switch too.

3 times in the past month, always toward the end of the day, running in with following sea, the boat falls on its face. The first time it seemed to die completely, then start right back up. The second and third time it continued to run, and after a few moments I could get back under-way. In each case I backed off the throttle and ran in just fine; under 2600 rpm.

I tried running the boat under different perko settings and it happened under all and 1.

I suspected a short in the auto bilge pump and replaced as it seemed to happen after a long day of fishing and using the wash down. No luck....still happened after the swap.

I checked the engine fuel filter, no water and crystal clear.

Today I will check the carb filter. 6 months ago I had the carb rebuilt as the float was sticking and flooding.

I have more details but this should get the discussion started. Your feedback is greatly appreciated!

 

[Bondo]

Ayuh,.... Havin' 2 fuel filters, the original, 'n the racor, can add unneeded restriction,....
Ya only need 1,...

I'd suspect a fuel problem, but checkin' the voltage at the coil's (+) terminal, when it's failin', might give ya a lead to the problem,...

 

[alldodge]

As Bondo mentioned, don't see any need with 2 fuel filters, only can create more issues. Since it runs fine until later in the day, I'm thinking gas tank vent or anti-siphon valve. May also be a weak fuel pump but being fairly new I would put it on the back burner

 

[Hook'd]

I'll try and post some photos of my findings tomorrow. I found corroded connections from the oil-pressure sender back to the fuel pump, and a loose ground on the fuel pump also. I fixed all of that up. I also found a lot of debris in the carb filter, and cleaned it. I also found what I'm guessing is emulsification in the racor. No water though which is good news.

Good advice bondo and dodge. I'll ditch one of the filters. I'm not sure if I have a antisiphon valve. I do have a trap on the vent to keep water from coming in. I just ran it up a few inches then back down. Might be a kink there.

I'll run it this week and see if it resolves.

Thanks

 

[Hook'd]

Bondo, how would I check the voltage at the coil +?

 

[Scott Danforth]

Volt meter

 

[alldodge]

The ant-siphon valve is on top the tank and the rubber fuel line connects to it. It has a spring loaded ball inside and can get sticky due to crud

http://www.iboats.com/Moeller-Anti-Siphon-Valves/dm/view_id.392106

 

[Hook'd]

Thanks dodge...will check that. Bondo, I anticipated that response. What should it read?

 

[Hook'd]

Meant to say Scott, anticipated from Bondo...lol

 

[Bondo]

What should it read?

Ayuh,.... 12v,...

 

[alldodge]

Measure from the positive post on the coil and ground on the engine block

 

[Hook'd]

I've now replaced the fuel pump, filters, oil safety switch, and made sure it was venting. There is no anti siphon, rather a shutoff valve. I now suspect the coil or module over heating. This started after I installed a heat exchanger on the engine btw. But the boat never overheats and runs consistently at 160. Could this be related?

Today I noticed carbon, and wearing at the coil lead in the cap. The cap also had green/white corrosion at the cylinder leads in the cap. The module screws were really rusted.

I'm thinking to purchase a new module, coil, cap, and rotor, and swap them out. Is there a difference between what I get at my local auto parts store for these items, and marine specific? Does this sound logical? I was also told I could try cooling the coil with say ice in a towel next time it happens just to check.

Thoughts?

 

[Hook'd]

BTW, I found the following numbers on the distributor; 1103799. I believe this is a deco voyager est hei marine. It is totally possible there is a mismatch of parts from cap and rotor to module and coil. Anyone have the correct part numbers for this ignition and a 5.7 V8? The valve covers have 4 bolts, and I believe the rebuild is a indmar.

 

[alldodge]

I've now replaced the fuel pump, filters, oil safety switch, and made sure it was venting. There is no anti siphon, rather a shutoff valve. I now suspect the coil or module over heating. This started after I installed a heat exchanger on the engine btw. But the boat never overheats and runs consistently at 160. Could this be related?

Today I noticed carbon, and wearing at the coil lead in the cap. The cap also had green/white corrosion at the cylinder leads in the cap. The module screws were really rusted.

I'm thinking to purchase a new module, coil, cap, and rotor, and swap them out. Is there a difference between what I get at my local auto parts store for these items, and marine specific? Does this sound logical? I was also told I could try cooling the coil with say ice in a towel next time it happens just to check.

Thoughts?

As Bondo mentioned having two filters in line can have its own issues, only way to know for sure is to put a fuel pressure gauge inline between pump and carb. Should read 4 to 7 psi

Corrosion inside the distributor isn't good no matter which component it is. Still don't think its the coil right now, leaning more toward a bad connection. Cap and rotor would be a good move, as for the module, I would remove clean and re-install

 

[Hook'd]

Alright...today I'll bypass the second filter, and run it tomorrow. How do I check the coil voltage (specifically) knowing it is a est.

Also, I know there is a specific procedure for setting initial timing for the ignition. Could the advance be creating heat and messing up the components; module, coil, corrosion I am seeing. I ask because the rotor and cap are not even 6 months old.

 

[Hook'd]

Hey guys, BTW, everyone agree auto parts store rotor, cap, module, coil are fine in lieu of Sierra, etc?

 

[alldodge]

Hey guys, BTW, everyone agree auto parts store rotor, cap, module, coil are fine in lieu of Sierra, etc?

Yes

As for the cap/rotor corroding in 6 months, then just clean up

Bypassing the other filter can be good, but still needs pressure test to verify status. If it does clear up, then this shows there is an issue, but not sure its working at 100 percent.

 

[211libwtfo]

I didn't think I had an anti siphon valve either because it jus looks like a barbed hose fitting. Took me several times to check it. Replaced all good like gravy on a biscuit. Most all tanks have em.

 

[Hook'd]

Update...

Today I went out crabbing to test out the removal of the 2nd racor. The other things I did differently were run on the bottom half of the tank, and clean the flame arrestor. It was a bit choppy, so I never opened it up beyond 2600rpm until the end. When I approached WOT it bogged. This time it did not die like it had the other times. I was able to back off slightly, and keep pretty high rpm's.

I however still lean toward ignition. The coil was'nt really even warm, but the bottom of the distributor at the module was hot.

While working on the boat yesterday I noticed the following wiring. The purple wire from the harness is spliced into 4 wires; the coil, the alternator (with resistor), oil pressure safety, and another wire. This wire hits the choke, and manifold sender. It then returns to an alarm in the dash, which does not work. This just does not seem right, and does not jive with the wiring diagram for the original boat. However, the Delco est is aftermarket, along with the electric fuel pump.

Could this wiring be at fault?

This all started when I installed a closed loop cooling system and second racor. Could the manifold sensor be overheating while the coolant temp sender stays at 160, causing the engine to die or bog.

I know I'm all over the place with this. Just putting it all out there to see if anyone can connect the dots.

Next outing will be specific to farret it out. I'm gonna install a pressure gauge, take new ignition components, and etc.

Any Insite is greatly appreciated.

Thanks!

 

[Hook'd]

I also wonder if my mechanic correctly set the initial timing per the instructions in adults only....