I think I may have a fuel pump crappin out. Need to know what you'all think. The f.p is set at 42lbs. w/line off and at full throttle it goes up to 60 psi. is this ok or do I need to get my hands on a new fuel pump. I have a walbro 307 now, was thinking about steppin up to a 340. need advice quick I have dyno pulls coming up this weekend.
fuel pump help
- Thread starter 6-FITZ
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striker_29
Senior Member
- Joined
- May 31, 2001
Depends on how much boost you are running, it should rise one lb per lb of boost. I would probably uncap the fuel rail, hook up a line and see how quickly it pumps out a gallon of fuel. It should only take so long to pump out a gallon of gas, can't remember exactly how long. Someone else will chime in with that I'm sure. Good luck.
Edit: Oh and I think that probably is the limit on a 307 anyway
Edit: Oh and I think that probably is the limit on a 307 anyway
striker_29
Senior Member
- Joined
- May 31, 2001
Well according to Red Armstrong, it should not go to 70, but I digress. If yours was and no longer is, I would definatley time how fast its pumping it out. Once again, I'm sure someone else will come along and tell us the rate it should be at. Either that, or just go ahead and replace it if your unsure, that is some very cheap insurance and like you said, you may want to step up anyway.
Dave Simpkins
New Member
- Joined
- Mar 17, 2002
PUMPS
Not sure where your fuel pump is mounted (on rear frame under trunk ?? or in the fuel tank ??) Anyways if you can get at it, remove it and take it to a "FUEL INJECTION" specialist ... they have equipment to etermine voltage draw of pump, max. pressure, and flow in Gallon P/M or Lirters/PM. A little more trouble to do this way but its a lot safer than running fuel into an open container.
I just had 2 Bosch pumps done at local Inject. shop (mostly they do HD diesel injectors and pumps but they are rigged to do anything that moves/ inject fuel) ... all testing, solvent cleaning and "pump dyno" results ... $10.00 per pump.
ds
Not sure where your fuel pump is mounted (on rear frame under trunk ?? or in the fuel tank ??) Anyways if you can get at it, remove it and take it to a "FUEL INJECTION" specialist ... they have equipment to etermine voltage draw of pump, max. pressure, and flow in Gallon P/M or Lirters/PM. A little more trouble to do this way but its a lot safer than running fuel into an open container.
I just had 2 Bosch pumps done at local Inject. shop (mostly they do HD diesel injectors and pumps but they are rigged to do anything that moves/ inject fuel) ... all testing, solvent cleaning and "pump dyno" results ... $10.00 per pump.
ds
striker_29
Senior Member
- Joined
- May 31, 2001
Check with Red Armstrong at Quad Air, he used to have the best price in town. But be aware, he will try to talk you into an XP
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Check my sig!The Radius Kid
Active Member
- Joined
- Jan 26, 2002
What's wrong with the pump you've got now?
42+17= 59 and you're seeing 60 under boost so the pump sounds allright.
That pump should be good to 22-23 #'s boost before it gives any reason for concern.If you can boost the voltage to the pump,you should be able to get low 11's/high tens out of it,with a set of 50# injectors.Mid 11's shouldn't be a problem.
We went through this on the southern board[T/B's.com].
Steve Wood e-mailed Walbro about the 307 vs. 340 and they told him the two pumps are within a # or two up to 65 psi where the output of the 307 rolls off and the 340 continues to around 70 #'s.
If you're not going to push the car that hard,don't worry about it.
42+17= 59 and you're seeing 60 under boost so the pump sounds allright.
That pump should be good to 22-23 #'s boost before it gives any reason for concern.If you can boost the voltage to the pump,you should be able to get low 11's/high tens out of it,with a set of 50# injectors.Mid 11's shouldn't be a problem.
We went through this on the southern board[T/B's.com].
Steve Wood e-mailed Walbro about the 307 vs. 340 and they told him the two pumps are within a # or two up to 65 psi where the output of the 307 rolls off and the 340 continues to around 70 #'s.
If you're not going to push the car that hard,don't worry about it.
- Joined
- May 26, 2001
That may be true, but in the last few years, I seen about 5 bad 307's and only one questionable 340's. Some died, stopped completely, others low pressure with very bad results.
Personally would not install another 307. Of course lots of guys will now say how great their 307 has been, but no convincing the guy with a blown motor because of a bad 307!
The Radius Kid
Active Member
- Joined
- Jan 26, 2002
To be honest Nick,I believe that the 307 is older model than the 340.That could explain why you've seen more 307's fail than 340's.
However he did indicate[according to his F/P gauge] that his 307 was functioning as per expected parameters.I had a 307[MM Muscle pump] that worked great up to the day I took it out for replacement with a 340.
Any indication why the 307's you saw fail actually died?Running too much voltage trying to push out the fuel maybe?
Junk went through them?
Alchohol enhanced fuels rotting the guts of them?
Kinked feed lines causing the pump to work too hard to produce the required flow and pressure?
Too much time running with a plugged fuel filter?
Bad fuel pump ground?
Just plain old age?
That last one happens to the best of us.
However he did indicate[according to his F/P gauge] that his 307 was functioning as per expected parameters.I had a 307[MM Muscle pump] that worked great up to the day I took it out for replacement with a 340.
Any indication why the 307's you saw fail actually died?Running too much voltage trying to push out the fuel maybe?
Junk went through them?
Alchohol enhanced fuels rotting the guts of them?
Kinked feed lines causing the pump to work too hard to produce the required flow and pressure?
Too much time running with a plugged fuel filter?
Bad fuel pump ground?
Just plain old age?
That last one happens to the best of us.
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