Fuel Pump And Ecm Relay Fixes
No fuel and no spark can be ecm related
Many foreign car ecm computers with carbureted engines and most American and foreign cars with fuel injection use an electric fuel pump controlled by the ecm. Unlike the mechanical fuel pump that requires an operating engine to be actuated, the electric fuel pump begins to operate as soon as the car's ecm grounds the fuel pump relay. Therefore, if a little piece of dirt or other contaminant gets under the needle valve in your carburetor, this electric pump could flood the engine or even pump the fuel tank dry if the engine computer were left on for a length of time. Click here to get expert ecm replacement advice on how to fix your ecu or buy a new ecm by calling 313-462-0124. Some electric fuel pumps are controlled by the ecm and most cars have eliminated this problem by having a switch that keeps the fuel pump shut off until the engine builds up oil pressure. Unfortunately, if one of these cars equipped with such a switch has been idle for a while, it may be difficult to start because the oil pressure may take some time to increase and there will be no fuel flow. If you have a car ecm with an electric fuel pump and you suspect fuel problems, do this.
Relay Not Grounding Fuel Pump
1. Check to see if the fuse protecting the fuel pump's electrical circuit has been blown. Most electric fuel pump systems controlled by the ecm have such a fuse. Generally, it is located in the fuse box under the dashboard. Your owner's manual will give you its location. A visual inspection will tell you if this fuse is blown or not. If it is blown, replace it with one of equal value.
2.Locate the electric fuel pump. Usually these pumps are in or near the fuel tank. Simply follow the fuel line (pipe) from the carburetor, moving back toward the fuel tank. There will be inlet and outlet connections on the fuel pump. There also will be an electrical connection, this is usually in the ecm engine computer.
First, determine if you have electric current flowing to the fuel pump by using a voltmeter. With the ignition switch turned on, connect the voltmeter ground lead (black wire) to a good ground on the car frame. Touch the positive lead (red wire) of the voltmeter to the electrical connection on the ecm .
4. If you do obtain this reading and the ecm will not make the fuel pump operate, replace the pump. If you do not obtain the correct voltage, the problem is somewhere between the fuel pump electrical connection and the ecm. You might be better off to consult a professional mechanic in this case.
5. Turn off the ignition switch.
If you determine that the ecm needs to be replaced, be sure you obtain one that meets the minimum requirements of pressure and volume for your particular car. Try to find the correct part number and Consult our technicians if you have any ecm questions.