Honda Civic 1988 (D-12 Carby) Fuel Pump Issue

[Navqam]

My Dear Pakwheels Fellow Members,

Salam,

From last two months, i am facing some fuel pump issue in my civic. Presently a Mitsubishi Electric Pump is installed by-passing the mechanical one originally installed (due to leakage/malfunction and non availability of Japanese mechanical pump). In start its ok, by passage of about 10-15 minutes drive it starts making (tttttrrrrrrrrrrrrtttttttttttrrrrrrrrrr sound). Fuel tank level showing more than a quarter fuel capacity. With the sound it becomes extremely hot (un touchable). It is fixed in the engine bay with left shock absorber mounting. I need your kind advise to replace/repair with another 'Electric' or find its original 'Mechanical' fuel pump. If anybody can tell me its availability in Rawalpindi/Islamabad, i'll be very much obliged please.

[Navqam]

so many views & no comment? Xulfiqar bhai pls comment....

[OwaisYunus1]

It would be best to look for the mechanical pump and replace the electric one with it. The carburetor is not designed to work under so much fuel pressure, especially if there isnt an fpr installed which I'm guessing is not. Also, get the pick up point in the tank checked if its clogged. When you say that its installed outside, is the return feed of the pump connected back to a return line to the fuel tank? I'm guessing that the mechanic blocked the hole on the pump which releases excess back pressure in the pump so that it can be installed outside. If that is so, there must be alot of back pressure inside the pump, causing the pump to overheat. If you could take a pic of the location where the pump is installed, it would be easier to diagnose the problem.

[Navqam]

Mr. Owais, many thanks for the reply. The electric pump has two pipes installed (one coming from tank for intake and the other one to carburetor for supply). Whats the 'FPR' you mentioned? The electric supply is supported with a 'relay', installed separately. I will try to post the pic (as desired) ASAP. By the time pump starts making noise, there is a lot of petrol smell, as it is leaking somewhere, but on inspection found no traces of it. On acceleration, the car first loose power and suddenly takes up.

[OwaisYunus1]

Depending on the type of pump installed, that seems to be the wrong configuration. An FPR is short for Fuel Pressure Regulator. The purpose of an fpr is to reduce the pressure of the fuel in the fuel supply to the engine. Let me tell you how it works. There is one pipe coming from the fuel pump which goes into the fpr. One pipe exits from the fpr to the engine and another pipe exits from the fpr and into a return line, going back into the fuel tank. Depending on the engine's requirement for fuel, the fpr sends the appropriate amount to the engine and then releases the excess fuel into the return line to go back into the fuel tank. For the fpr to know how much fuel is required, a vacuum line is connected to it which helps it control the fuel pressure depending on the change of vacuum.
In order to diagnose the issue, you will need to share some detailed pictures of the engine bay where the fuel pump is installed.