Saturday, August 23, 2008
1985 Camaro, the engine will start but not stay running.
QUESTION: I have a 1985 Camaro, 2.8 litre multi-port fuel injection. The motor has about 55,000 miles on it. I was driving down the road when it lost power. Now the engine will start but not stay running. I can hear the fuel pump running. ANSWER: First thing you will want to do is check for any computer codes. This can be done by you . Extract GM Codes . If there are any codes, repair as needed or let me know what the codes are if you are not sure what to do. If there are no codes then, you need to have the fuel pressure tested. It needs to have at least 40 psi with just the key on and the engine not running(see testing procedure below). If not, replace the fuel pump. Another way to test this is to have someone spray starting fluid in the air filter while you start it and keep spraying to see if it will stay running. If it stays running on the starting fluid, then you need a fuel pump. TESTING 1) Relieve the fuel system pressure and check that there is an adequate quantity of fuel in the tank. 2) Connect a fuel pressure gauge to the pressure connector fitting located on the end of the fuel rail. Fig. 1:Fuel pressure can be checked using an inexpensive pressure/vacuum gauge 3) Make sure the ignition switch has been in the OFF position for at least 10 seconds and that all accessories are OFF. 4) Turn the ignition switch ON and the pump will run for about 2 seconds. Note the system pressure with the pump running, it should be between 40-47 psi. NOTE: The ignition switch may have to be cycled to the ON position more than once to obtain maximum pressure. It is also normal for the pressure to drop slightly when the pump first stops, but it should then hold steady. 5) If the pressure is not as specified, verify that fuel pump operation is heard in the tank. 6) If fuel pump operation is not heard, inspect the fuel pump relay and wiring. 7) If fuel pump operation is heard, inspect the filter and lines for restriction. 8) Start the engine and make sure the pressure decreases about 3-10 psi at idle. 9) If fuel pressure does not decrease, inspect the fuel pressure regulator and hose. 10) Disconnect the fuel pressure gauge.