Ok so my m37 318 is running bad it will run fine then it will chug until its ded

[bubba_got_you]

Ok so my m37 318 is running bad it will run fine then it will chug until its ded. I the problem only happens at idle
There is no unusual noise so I figure it’s a fuel problem because it will run fine then no go. It will restart after I pump the gas and crank for 30 sec.
[FONT=&quot]So I replaced the fuel filter thinking maybe it’s clogged…nope…. but I did replace with a glass filter so now I can see what’s happening. So when its at idle the fuel filter will run almost dry with the pump only spattering a little bit of fuel in and the filter is practically empty. Im thinking a bad fuel pump? Because it only happens at idle and will run ok with the idle way up. Maybe a hole in a diaphragm? [/FONT]

 

[nk14zp]

Sounds like fuel pump to me.

 

[bubba_got_you]

thats what im thinking but i wanted to post up so in case someone has a different idea.

 

[clinto]

Go test your fuel pump. Get a vacuum/pressure gauge (see picture below) from anywhere-Lisle Tools, Sears, Snap-on, etc. Disconnect the outlet hose from the fuel pump and have someone turn the engine over with the starter. The gauge should read to full pressure with 2-4 pumps and the needle should stay (i.e. not lose pressure). Once the pump has cycled 2-4 times, the needle should stay more or less in the same place.

 

[stalker]

Do you have a mechanical or electric fuel pump? If mechanical then I would think that could be your problem because a weak pump could compensate w/ higher rpm but not an electric model. Just a thought.

 

[bubba_got_you]

Do you have a mechanical or electric fuel pump? If mechanical then I would think that could be your problem because a weak pump could compensate w/ higher rpm but not an electric model. Just a thought.

its mechanical that's why im thinking that's what it is.

 

[bubba_got_you]

Go test your fuel pump. Get a vacuum/pressure gauge (see picture below) from anywhere-Lisle Tools, Sears, Snap-on, etc. Disconnect the outlet hose from the fuel pump and have someone turn the engine over with the starter. The gauge should read to full pressure with 2-4 pumps and the needle should stay (i.e. not lose pressure). Once the pump has cycled 2-4 times, the needle should stay more or less in the same place.

why didn't i think of that. i got a Gage sitting in one of my tool boxes
[FONT=&quot] But the last thing I want to see it it be ok……because it means its something else lol [/FONT]

 

[bubba_got_you]

oh it wasn't the pump care to guess what it was?...............if not ill post what it was in a few

 

[stalker]

My quick guess is stuck choke

 

[acmunro]

I was just reading through and thought it could be a bad line on the suction side of the fuel pump.

 

[dc3coyote]

Have you cleaned the carbs lateley? Is it tight on the manafold?

 

[sak00]

I cheated, I know, I know..........................

 

[bubba_got_you]

the float had a hole in it it just kept poring gas in the carb and flooded it now that's fixed now for the rear mane.

 

[stalker]

If the float didn't have a hole in it then it would have been a stuck choke.... like I said. I declare myself "CLOSEST TO WINNING"

 

[jimmcld]

I would have guessed a clogged tank filter.

 

[badgmc56]

The reason the fuel filter was getting dry is as the motor was being flooded, the RPM was dropping and the pump was not pumping enough to keep up with what the carb was dumping in. If you suspect a flooding carb, just look down the throat of the carb and you can see fuel dumping in. You should not see any fuel being introduced unless you are opening up the throttle. Then you are activating the accelerator pump.