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LM318 Hard Starting

joe_l

joe_l

Contributing Member
Since it is mid winter and all of you boaters in the north are on the hard, I thought I would give you some thing to think about during those cold winter evenings.

In 1980, lived in LI NY and finished a 29 ft Dyer bare hull and installed a LM318BW1:91:1.
The boat was used a 150 hours annually and it always started immediately regardless of temperatures.
During the early 90's she started to exhibit excessive cranking after a hot shutdown (when i stopped for fuel). it was necessary to open throttle to start her. but was fine on the initial start of the day.
After another 4-5 years it became difficult to start after sitting for a week. the carter carb was empty and needed to crank long enough to fill it and the started fine. This is after 15 years on the engine.
Much TS, parts changing and edelbrock carb and nothing ever found wrong, so I lived with it for another 14 years.
So in 2009, after well over 3500 hours and 29 years I installed a long block. The engine started immediately for two years and now is starting to exhibit the long cranking due empty carb bowls.
There is absolutely nothing wrong with the fuel delivery, ventilation, elec or cooling systems on the engine. I could install an electric fuel pump to prime it, but I am more interested in WHY.

My question for the deep thinkers, those of you who responded to the 318 # 1 cyl post:

Why did the problem occur after 15 years of operation and then after two years on the long block

Enjoy,
Joe
 
joe_l said:
Since it is mid winter and all of you boaters in the north are on the hard, I thought I would give you some thing to think about during those cold winter evenings.

In 1980, lived in LI NY and finished a 29 ft Dyer bare hull and installed a LM318BW1:91:1.
The boat was used a 150 hours annually and it always started immediately regardless of temperatures.
During the early 90's she started to exhibit excessive cranking after a hot shutdown (when i stopped for fuel). it was necessary to open throttle to start her. but was fine on the initial start of the day.
After another 4-5 years it became difficult to start after sitting for a week. the carter carb was empty and needed to crank long enough to fill it and the started fine. This is after 15 years on the engine.
Much TS, parts changing and edelbrock carb and nothing ever found wrong, so I lived with it for another 14 years.
So in 2009, after well over 3500 hours and 29 years I installed a long block. The engine started immediately for two years and now is starting to exhibit the long cranking due empty carb bowls.
There is absolutely nothing wrong with the fuel delivery, ventilation, elec or cooling systems on the engine. I could install an electric fuel pump to prime it, but I am more interested in WHY.

My question for the deep thinkers, those of you who responded to the 318 # 1 cyl post:

Why did the problem occur after 15 years of operation and then after two years on the long block

Enjoy,
Joe
Click to expand...

Sounds like the classic signs of vapor lock to me. Also, do you pump the throttle 3-5 times before starting, and crank with the throttle 1/3 open, as recommended in the manual?
 
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"I feel your pain!" (Clinton)

Actually, I do. Both of my Edelbrocks (and the Carters before them) do the same damn thing every time I leave the boat for a week or so. For some reason other boaters do NOT have this problem--some do, some don't. Go figure. I think the volatility of modern gas has to have something to do with it, but...

That said, I totally eliminated this hassle by installing an electric booster pump that is "Tee'd" into both carbs. (One pump for two carbs.) A tiny, 1/8 inch copper line sends gas to borh carbs, filling them, before I grind the starters. Motors then start right up, which is better for them (and my nerves! Grinding and grinding a starter eats them up, and also does damage to the engine's bearings.) To prevent backflow when the motors are running, a check valve is used at each carb.

Here's the drill (and I NEVER fire the engines up witout waiting 4 minutes):

1. Crank the engines--knowing they won't fire right up--to make sure no water got in (from the exhaust or a leaky manifold, riser, etc.) This is my standard procedure since I hate bending rods and blowing head gaskets. It should be yours as well! (I shudder to hear my slip neighbors crank 'em right up after sitting, some times for weeks. A tablespoon of water in a cylinder is enough to blow it all to hell!)

2. When the engines turn over smoothly (meaning RRRRR not RR--hesitate---RRR--hesitate...) I hit ther bilge blowers and turn on the 4 minute electronic timer (a cheapo from the dollar store).

3. I then toggle the electric booster pump to ON.

4. Four minutes later the blowers have done their job (I never turn them off when the motors are running) and the carbs are full

5> I then fire up the motors and turn OFF the booster pump.

So far (two years now) this setup has worked beautifully! Though a bit of work and cost (about 50 bucks for a small, marine fuel pump, tubing, check valves and fittings), it's been a blessing.


Jeff
 
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Jeff,

Isn't it dangerous to turn the motors over without running the blower first? It would seems to me that as soon as you are cranking the engines you have created the opportunity for a stray spark (from the starter, coil, loose wire, etc.) and if the blower has not properly removed any fumes, you have a bomb. I have a similar procedure but it always starts with the 4 minute blower operation, coupled with opening up the hatches and checking the fluids before cranking.
 
Correct! I errored in my listing. The blowers do go on first, and you have a very valid point: I should run the blowers 4 minutes before doing the initial crank over (to check for water injestion), THEN run the electric pump long enough to fill the carbs.

Have never considered that (like a dope!)

Thanks.

Jeff
 
I always like to lift the hatches and " look and smell", as soon as I get on the boat. This way you can check the bilge also (just to make sure your pumps are working). Being old Chryslers I'm reserved to the fact that they are going to need some pumping. After lifting the hatches and inspecting everything I run the blowers for a couple of minutes then pump the throttle six times, turn starter for about four seconds, turn the key off, pump another four times then hit the key and she fires up. This usually works every time and does'nt kill the starters.
 
It does'nt make sense does it, even my old 66' Mustangs 289 only needed three to four pumps and it would fire up. Whether the boat sits a day or a week, pump,pump,pump ???????
 
this is what I do.. After a week of sitting.
Lift the centre section of floor, look & sniff
Hit the blowers for a coupls of mins
Crank engine for a bout 20 seconds
Pump twice & turn the key....purring
Rinse & repeat for the other side
Forty yr old fresh water 318's with 5 yr old Edelbrocks & mechanical pumps
 
Repeated 20 second cranking is bad for the starter, ring gear, and the engine in general. Mine took about that long before I do something about it.

Strange that some boaters, with different carbs/ motors/ hulls don't seem to have this problem.

Jeff
 
On my trailer boat with the 318, I put in a prime bulb inline with the fuel line. I would pump it 5-10 times and she started right up. same concept. That boat also suffered this problem with the carter and the edelbrock befre I put the primer in, I figure is saves my batteries and the starter.

will
 
Will:

Boy was I tempted to do that as well, but mine is an inboard and a rubber bulb below deck is illegal. (Being a CG Aux guy I have to toe the line.)

Buick430:

I assume you messed with a Buick 430/ 455? Hell of an engine! I recall a hop up comparison done by 'Car Craft' in which the same mods were applied to all of the popular big blocks (Chevy, Ford, Pontiac, Olds, Mopar, and Buick). Guess which engine made the most power!

Jeff
 
Jeff, I had no idea the rubber bulb below deck is not allowed (and Im active duty CG!) I guess I need to brush up of the BOJAK. And yes I have been messing around with big block buicks for a while. I actually just dropped a mild 430 into my 69 riviera. THey are some very torquey motors!

regards, Will
 
My 360s have always suffered from the "ever crank" problem on cold startup. I'm about to install two new Edelbrock 1409 carbs but from what I read above, that probably won'r help much with cold starting.

What about electric fuel pumps? There are a number of simple pumps that seem to be used in marine applications.

Bill
 
Appreciate all the input but:
The original question was WHY would the engine start fine for 15 years and then the long block for two years before the long cranking became an issue.
Joe
 
Joe,
You mentioned "empty carb bowls" in the earlier post. IMO, I think I'd start here.
Either the fuel delivery system isn't filling the float bowl completely, (restriction, filter, weak fuel pump, etc.), a carb issue, or the fuel is leaking into the intake. After shutting down and before you try to restart, visually check the carb pump. Disconnect the throttle linkage at the carb. Hold the choke plate open and while looking down the throttle bores, one time only, push the throttle to full open. You should see fuel shooting down into the primary bores almost if not immediately as you open the throttle. Should be a stream and not just a dribble. Seeing little or nothing could mean too low bowl fill, bad carb pump diaphram, clogged carb pump port, stuck check ball / valve. Let us know what you find.

I doubt a float bowl full of fuel could evaporate in a week if the carb is sealed correctly. In the event fuel is leaking into the intake, you probably could smell it in the crankcase oil.
 
...."I doubt a float bowl full of fuel could evaporate in a week"

Me too, but it DOES! I pulled the top off to find out--empty (and there were no bowl leaks, the only way the gas could escape). After that revelation I tried a new trick: I ran the motors a few seconds just before leaving the boat (after a ride) before leaving her for a week. That helped a bit, but... Still evaporates.

Jeff
 
Installing a brand new edelbrock 1409 had no effect on the original engine and second new edelbrock 1409 had no effect on the long block. The fuel used is valtec which sold as containing no ethanol. The fuel is evaporating and as Jeff stated the carb bowls are empty.
This was confirmed by removing the top cover. There is no fuel in the oil.
But why after all that time?
 
Dammed if I know! And it ticks me off that some boats have this problem, where other don't at all.

That's why I installed my electric boost pump deal to fill the bowls. Works slick.

Jeff
 
Yikes! Gas Gremlins!! :( Just kidding.

Have you verified the bowls are actually full after shutdown?

Would be interesting to test how long it takes for 4 or 5 ounces of fuel to evaporate in open air in that area.
 
The heat off the engine could accelerate the evaporation after shut down.
Edelbrocks are wider and sit over the exhaust crossovers were as the
Holley is more length wise with the bowls extending away from base.

Maybe that's on purpose. Mine starts right up after sitting for weeks at a time.
Even when I take it out of storage a little extra pumping and she fires right
up. I've been looking at a 1409 or rebuilt Carter to make the boat more original
but starting has never been an issue. I always blamed the carbs for Chrysler's
reputation for poor starting anyway.


Jack
 
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