Engine almost starts then dies...and ideas?

Sanmiam · **Joined:** Sat Mar 24, 2012 9:05 pm **Posts:** 84

Ric - what exactly could be leaking? With the exception of the vacuum tube from the carb to the choke, I did not think the boat had any other vacuum actuated system (PCV, timing advance, ERG, etc etc)

ric · **Posted:** Tue May 22, 2012 8:35 am

Sanmiam wrote:

Ric - what exactly could be leaking? With the exception of the vacuum tube from the carb to the choke, I did not think the boat had any other vacuum actuated system (PCV, timing advance, ERG, etc etc)

Carb gaskets, intake manifold gaskets, there should be 1-2 vacuum ports with plugs on the carb (that should have a plug on them), head gaskets

Sanmiam · **Joined:** Sat Mar 24, 2012 9:05 pm **Posts:** 84

Ah ha - makes sense.

Rather than require a two man operation couldn't he place a piece of something over the carb intake (that is big and sturdy enough to not get sucked in - thinking a piece of flat steel or the like) over the carb opening and try cranking it as a work around to make it a one man operation?

Also - I believe the carb is a Holley on the boat and I just checked the Holley my Jeep to confirm - the choke valve on my Jeep is completely shut at rest. Different model carb but perhaps it is the issue???

Paul I. · **Posted:** Tue May 22, 2012 8:53 am

PDACPA wrote:

Here is my short story.

Boat running great, stalls out. Cranks will not start. Short tow to Marina thinking low on gas or water in tank. Takes 22 gallons of fuel in a 32 gallon tank. Fires right up. Drive back to ramp (about 30 minute run, no wake and at speed).

Week later, put in a new fuel filter ( old one had no water in it) and treat the tank with Sentry fuel treatment in case of water in the fuel tank.

http://www.sentrytreatments.com/

Cranks, almost catches, won't stay running. See fuel shooting in carb. Pull fuel filter, top it off with fuel, but was full from when I put it on and re-coated the seal. Same problem, won't start. Check forums, they suggest anti-syphon. See my thread on it, but finally installed new anti-syphon and pick up. Engine does the same thing.

Change the plugs (old ones were pretty bad. Change the distributor cap (some corrosion), change the rotor too. Replaced one spark plug wire as it broke during plug change. Engine does the exact same thing.

Install a new relay at the fuel pump (it had some corrosion). Try again, engine does the same thing.

I have to been able to get a new fuel pump, but searching for one tomorrow. Is there anything I overlooked? I see fuel shooting into carb when I pump th throttle and it almost starts, but will it stay running.

Here is a link to a video of what it does. Any advice is or ideas is appreciated. Admiral is praying runs for memorial day!

I hope I did not miss any thing from past postings! I am a bad reader. I sound like the carb needs to be rebuilt. I think it is gummed up or something along those lines. As someone else pointed out, its not the fuel system or the ignition system. It starts.

Bliss36 · **Posted:** Tue May 22, 2012 8:59 am

The butterflies are soaked,you have a massive pump shot, and it doesn't make a difference if you spray starting fluid straight down it's throat....at this point I would move on to checking the primary side of the ignition system. Pull a spark plug...I bet it's soaked. Is the spark weak and dropping out? With all the corrosion you have described is it not feasible that you have high resistance at a connection somewhere in the primary side of your ignition? A poor ground?

PDACPA · **Posted:** Tue May 22, 2012 9:12 am

Plugs are brand new (installed yesterday and replaced one plug wire) and they were dry. Not soaked at all.

Yes, spraying "starter fluid" in the carb while trying to crank will not get it started.

It sounds as though it is ready to catch and in some attempts does sort of catch then totally dies when you let go of the key.

Same reaction on each time:

1. Tried cold with no choke.
2. Cold and choked it.
3. Pumped the throttle in neutral and tried.
4. Turned key and pumping throttle as turning the key.
5. Same as #4 with someone spraying starter fluid.
6. Poured some fresh fuel in the carb and tried.

ric · **Posted:** Tue May 22, 2012 9:18 am

Well on the triangle of fire.... we can remove fuel from the equation. All that's left now is air and ignition. Too much air (leak) or spark issue.

Bliss36 · **Posted:** Tue May 22, 2012 10:17 am

Sorry I'm not trying to beat a dead horse here...only trying to help. I've missed a holiday weekend a few years ago due to mechanical failure and I know how frustrating it is.

Quote:

Change the plugs (old ones were pretty bad. Change the distributor cap (some corrosion), change the rotor too

When there is high resistance (corrosion) in the secondary portion(wires,plugs,cap and rotor) it can cause failures in the primary portion of the system like the coil or ignition module. Here's a few easy checks:
http://easyautodiagnostics.com/gm_icm_dist/distributor_ign_module_1.php
I believe this is the system you have but if not they have tests for all the GM ignition systems. Good luck!

PDACPA · **Posted:** Tue May 22, 2012 11:05 am

Bliss - according to that link, the ignition module sounds bad.

See my pic. Is that it? Thanks

EDIT: that is the old Distributor cap ( you can see the corrosion) and I replaced it and the rotor yesterday.

Bliss36 · **Posted:** Tue May 22, 2012 11:24 am

Yes! Do you have an Autozone by you? If you do they should be able to test it there. Those bolts that hold it on might be a goofy size like 5.5mm. I'll keep my fingers crossed for you!

taz42169 · **Posted:** Tue May 22, 2012 11:34 am

Have you tried testing your coil? Is it possible your coil is wet or damp? That would cause it to turn over and not fire up! Just a thought.

I had an issue with mine a while back. Manifolds (which I admit needed to be replaced), sprung a small leak (pinhole). It sprayed water onto my coil and the symptons sound similar. I had to pull over the hatch, dry off the coil and wires to get back to the marina. Fortunately (or unfortunately), we had a hurricane move up the coast a week later and I pulled her out for the season. Replaced risers and manifolds and no longer have water spraying on the coil...

Again, just a thought....

PDACPA · **Posted:** Tue May 22, 2012 11:41 am

Manifolds and Risers are new as of last summer. I am going to grab a coil and the ignition module and the fuel pump today and install this afternoon. I just cant get out of the office.

Paul I. · **Posted:** Tue May 22, 2012 12:53 pm

From all the new post, sorry I must be wrong. I had the same problem years ago, it was the carb.

PDACPA · **Posted:** Tue May 22, 2012 2:46 pm

Here is my plan for this afternoon/evening. I am going to install one at a time and test. Will let you know if it works.

1. Install new pick up coil sensor.
2. Install new coil module.
3. Install new coil.

and hopefully will not need to do this step as the part is expensive ($240)

4. Install a new fuel pump.

At this point, if it is not running, I might have to have the mechanic look at it. I could try pulling the carb, but it has been a long time since I have done that and I am trying to get it running for Memorial Day.

ric · **Posted:** Tue May 22, 2012 2:58 pm

Boats never seem to run when you need them. I remember last year I was going to take this girl out on a date on the boat. The night before the power steering pump seized up at 8pm and she was coming over in the early afternoon. I had to drive 30mi to an Autozone that closed at midnight to pick up the GM pump and pulley puller and spent the following few hours swapping out the pump. GM power steering pumps are only $35 but come as the pump only, no tank or pulley. You have to swap that with the VP one. In the end, I didn't even get laid the next day.

www.iFourWinns.com

Engine almost starts then dies...and ideas?

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