Hi,

94 Accord I4, approx. 160k miles (270k kms). plugs/wires/cap/rotor/timing belt and fuel filter were all replaced within the last two years 20k miles.

When the fuel tank is at 1/4, the car will often "stumble", idle drops and cuts-out at stop lights. No drivability problems when the tank is full. This only happens after reaching below 1/4 tank.

Is this a sign that the fuel pump is on its way out? I've read that this is rare in a Honda....

Is there a way for a tech to diagnose a dying fuel pump? Just want some educated advice before taking the car in to the tech.

Thanks

 

if you have access to an oscillascope,(snap on works good) then you can use it to see if it is indeed the fuel pump acting up or another culprit. Compare the siganl waves to when the car is acting up. Also check fuel pressure when below 1/4 tank, make sure within specs.

 

Thanks skracer13. Appreciate the prompt reply. I'll get the tech to check the fuel pressure when below 1/4 tank. I ran out of gas last summer, and noticed this happening shortly after, so I suspect fuel pump.

 

The fuel pump body or pickup hose could have a crack in it causing air to be sucked in when fuel level is low.

 

Thanks Phootbag.

Fuel pump body and pickup hose are both inside the tank right. Is this a common problem you have seen?

 

I dont think its a common problem. Usually its the fuel pump that goes bad not the hoses.

 

The oscilloscope is my choice as mentioned above, ask your tech if they have an AMP Clamp, do an AMP ramp and evaluate it on the scope, a tech with experience will know what to look for, just look at it after you are having problems.

Not exactly but you can compare wave patterns to another DC motor on your car or the alternator just so you can get a look at what should be going on there, nice even humps. The amount of amps being drawn will require even more experience and a library of wave patterns to make an informed decision on the amount of draw.

 

I've seen it once. I would call it very uncommon. However, the fact that you pointed out the symptom going away when the tank is above 1/4 tank leads me to suspect this as a possibility.

 

I am with phootbag on that too, also when the fuel gets low and the fuel pump is not completely immersed in fuel, it tends to heat up and create electrical issues too.