If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol...

americands

Cadet
Joined
May 7, 2012
Messages
25
So im troubleshooting the sh****t out of this problem I'm having. Again, 2001 Caravelle Interceptor 212. Max RPM is 3,000 then it either dies or boggs. I've replaced my plugs, fuel pump, fixed my carb, had my coil checked, im sure theres a few other things I've done (Oh, I ordered a new alternator an hour ago since I guess this partially controls the pump). Anyhow, I disconnected the fuel pump and there was a 12'' hose that went down, then into my boat (fiberglass cannot follow). I got down in my engine area and tried sucking the gas from the hose with my mouth....

1. Should the gas freely flow from that hose to the pump, given I just tried to suck it out? If not, wouldnt that mean theres some type of clog or something?

I cant seem to find where this hose connects to my gas tank. if I can find my gas tank I can take off the hose, inexpect the hose and possibly check the anti siphon valve I've read about for the past few hours.

This is really starting to get to me... cannot exceed 3,000 rpms.

Im in my early 20's. Im trying to "learn" how to do this stuff as opposed to just taking it somewhere.


Serial:
4012049068

Product No:
3869058

Engine:
Volvo 5.7GSPEFS
 

kelleyja

Seaman
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Feb 9, 2011
Messages
62
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

1. Should the gas freely flow from that hose to the pump, given I just tried to suck it out? If not, wouldnt that mean theres some type of clog or something?


There should be an anti-siphon valve at the hose connection to the tank. You will likely not be able to overcome the spring pressure in that valve by sucking.
 

kelleyja

Seaman
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Feb 9, 2011
Messages
62
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

If you think you have a fuel pump issue, there is a sticky on how to apply a jumper to the fuel pump relay to make sure the pump is working.

When you say "fixed the carb" - how confident are you that its fixed properly? If it runs fine until 3000 RPM, it could be a problem with the secondaries in your carb. At high RPM the secondaries will open, allowing more air in.....if there are clogged jets, you'll end up with a lean condition and exhibit bogging and stalling. Just a thought.
 

Don S

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Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

The alternator has nothing to do with your problem. All it does is activate the relay, it does not meter pump output.

Have a look at this thread, and do the test. http://forums.iboats.com/showthread.php?t=283269
 

biggziff

Seaman
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Apr 15, 2012
Messages
54
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

I was able to pull fuel with suction from my mouth as well as a vacuum pump at very low vacuum. I cannot get a siphon started on the same line though.
 

Don S

Honorary Moderator Emeritus
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Messages
62,321
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

I cannot get a siphon started on the same line though.

There is a part called an anti-siphon valve in the pickup tube going down in the tank. Think about the name for a minute.
 

americands

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May 7, 2012
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Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

So I found my gas tank.... So it was under my back seat aparently under a life vest... stupid, that I didnt look in such a simple, assumable place? Anyhow, so here's what I found...

1. I took off the fuel line, blew and it feel clears with no clogs.

2. I took a screw that had a bearing type deal in it. Is this the antisiphon deal? The fuel line connected to this. It didnt appear to be dirty or anything... I tried blowing through it and from it, and it was fairly hard to do that. if this isnt normal, anyidea on where I can get a replacement part? There was no part number on this.... I'm assuming this is the anti siphon device that some people were yappin about right?

3. From the anti siphon there was a metal square that when unscrewed, it had a 6-8'' hose that went down into the tank. This metal square was clear, the hose was clear as was the little screen vent on the bottom of it.

4. There was one thing I didnt touch. should I take this into consideration since my boat wont exceed 3k rpm? On the tank, there was a black thing that appeared to be flush and was screwed in. The numbers on it listed ((UFW-7.5 W39)). I google'd it, and couldnt find anything. Anyone know what this is ?

Im really desperate to find help. I suppose from the fuel tank ill go up until I find out why its not exceeding 3k rpms.
 

biggziff

Seaman
Joined
Apr 15, 2012
Messages
54
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

There is a part called an anti-siphon valve in the pickup tube going down in the tank. Think about the name for a minute.

That was my point (referring to the OP that mentioned the AS valve) that the AS valve probably isn't strong enough to prevent you sucking gas, but enough to stop a siphon. :)
 

bnicov

Petty Officer 1st Class
Joined
May 25, 2009
Messages
348
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

Start by doing what DonS said to start with. He's a Volvo tech and has forgotten more about VP engines and drives that the engineers at VP ever knew.
 

willscarver

Seaman Apprentice
Joined
May 8, 2012
Messages
43
Re: If I disconnect fuel pump, should I be able to suck gas w/ mouth from line? lol..

Stop sucking on anything related to gas. slow down. What was the condition or how was it running before you started.Did you change the float level.To low no top end.To high overflow at idle. Is timing on the money?
 
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