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454 requires a shot of fuel down the carb to start, but only after sitting a few days/weeks

C

ChuckC

New member
Hi all,
My 1985 Crusader 454 needs a shot of fuel down the carb in order to start after it' been sitting for a few days/weeks. I can crank it all day long (and/or pump the throttle), but it won't start until I give it a squirt of fuel manually. Once started, it runs fine all day long and will start up immediately. Until it sits unused for awhile, then I have to run the whole drill again. The accelerator pump appears to be working properly. Thoughts?
 
Thanks for the reply Rick. It's been awhile since I tested the accelerator pump, and come to think of it I'm not sure if it was before or after I got the engine running. I'll test it again in the next few days BEFORE I do the fuel squirt to start the engine.
 
Update:
I first noticed the problem described above at the end of last season. I put the boat to bed for the winter, and did a military deployment until arriving home last week. Thus, the boat has been sitting un-started (5 months) until today. I did the following, in this order, before cranking it over:
1. Remove fuel line from the output side of the fuel pump. No fuel drained out. (pump appears original - Crusader blue painted on pump, threads, etc).
2. Re-attach fuel line to the pump.
3. Test accelerator pump in the carb. Nothing.
4. Crank for 15 seconds. Test accelerator pump again. Nothing.
5. Wait 5 minutes.
6. Crank another 15 seconds. Test accelerator pump again. Still nothing.
7. Squirt fuel in the carb (1/8 oz or so).
8. Engine then fires off immediately and idles normally. Bring to operating temp then shut down.

I didn't have a chance to do a run above idle, but will be able to do so this weekend.
 
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ChuckC said:
7. Squirt fuel in the carb (1/8 oz or so).
When you squirt this 1/8 oz fuel into the carburetor, are you squirting it into the primary throttle bores, or into the fuel bowl vent tube?
If throttle bores, you have effectively compensated for what the accelerator pump is NOT providing.

Perhaps next time fill the fuel bowl by adding fuel directly into the carburetor's vent tube. (if the bowl is dry, it will require more than 1/8 oz)
This should allow the accelerator pump to function as though the fuel pump is working correctly.
Click to expand...
 
We've got the 86 version and what you are describing has been common since the ethanol fuel made its debut.....given the high heat in the engine compartment and the environment, especially in the summer, the fuel in the carb's bowl evaporates in a fuel days.

Some will blame it on the carb's plugs leaking but i haven't seen a 170 series qjet that had this issue.....
 
Thanks again gents for the reply. Rick, I'm manually shooting the fuel down the primary bore, in the same location the accelerator pump does. Mark, I've owned the boat for 4 years, and have only fueled with ethanol free fuel during that time from various marinas (but I certainly hear ya).
Update: yesterday had a buddy help. While troubleshooting previously, I've been manually pressing the accelerator pump on the carb, which squrts fuel. Yesterday I had my buddy work the throttle while I watched the carb - same result, fuel was delivered, yet no start after 3 throttle pumps after sitting for 2days. Yet a manual squirt later, fires off fine? So odd.
We did a full power run for about 2 minutes. I prefer not to comprehend what fuel twin 454s consume at full power, but there were no starvation issues during the run, so I'm assuming a carb problem instead of a fuel pump problem at this point.
Happy father's day everyone!
 
Lucky you w/ the ethanol free fuel.....

so you have fuel in the float bowl....have you check the choke settings and its operation?
 
Mark,
I haven't, but will do so next time I get a 'helper'.
That being said, shouldn't the accelerator pump be able to overcome any choke issues during initial start? Given my symptom and "cure" of a manual fuel squirt, it baffles me why I can't do the exact same thing with the accelerator pump (which appears to be working). I mean, I'm squirting fuel into the same spot as the pump!
 
Excess raw fuel in the intake may overcome any choke short comings but doesn't bode well for engine life....

What you are describing sure sounds odd in that your 'cure' duplicates what failed immediately before it....the only thing i can guess at thats different is the fuel in the bowl vs the squirt source.....if the fuel in the boat's tank(s) is untreated and over 90 days old, its characteristics may have degraded enough to make starting marginal....choke or not. and Im pretty sure the 90 day window still applies to ethanol free fuels....
 
Thanks again Mark. Over the weekend, I had my buddy crank both engines while I watched and compared (boat had been sitting unused for 1 week). We began with the "good" engine, which started without issue. Before cranking the troubled engine, I noticed the choke was very slightly cracked open, while the choke on the other carb was completely closed. I had my helper crank the engine for awhile with no start, but sure enough as soon as I pressed the choke completely closed with my finger it fired right off. I guess now I need to figure out how to adjust the choke spring and see if it's a permanent cure. Quadrajet.
Given some oddities while troubleshooting, there may be more than just one issue going on. Hopefully a choke spring adjustment will get me through the season, then perhaps it's time for a carb overhaul next winter.
 
Quadrajet.
Given some oddities while troubleshooting, there may be more than just one issue going on. Hopefully a choke spring adjustment will get me through the season, then perhaps it's time for a carb overhaul next winter.
Click to expand...

Ayuh,..... Those carbs are known for leakin' bowls, when left for a week,...... they leak into the manifold,......

The usual cure is to rebuild it, 'n epoxy the leakin' ports in the bottom of the bowl,.....
 
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