Cold Start Problem - '91 F150 4.9L
|
|
Cold Start Problem - '91 F150 4.9L ClydeWigg3 06-09-2004, 09:33 AM
Will crank right up then stall. Have to feather the pedal to keep it going, even then it idles very rough, coughing and sputtering until it warms up. Smokes when first cranking up. When motor is warm will crank right up without trouble. "Fixes" to date: New fuel filter; new plugs, wires, rotor and cap; new IAC, new cold start sensor, you name it. No codes. Fuel pressure is fine. Mechanics say it ain't the head gasket either. After sitting for a few days (4-5) it will crank and jump into high idle and not stall, but will run roughly. If it sits just overnight, will crank and stall. After it's warm she runs great. ModMech 06-09-2004, 12:10 PM Check the Engine Coolant Temp sensor for accuracy. If it is reading incorrectly, you will get either too much fuel (indicates cold) or too little fuel (indicates warm). Which would account for your symptoms. Also, be SURE you are getting BATTERY voltage to your coil while cranking. ClydeWigg3 06-09-2004, 12:14 PM Already replaced the Coolant Temp Sensor. Is there a way to test it? Concerning the battery voltage - how do you check that, and would it make a difference if the engine was hot or cold? 97chevyman 06-11-2004, 08:57 AM how many miles are on your oxygen sensors? Related Links Enter the largest automotive community on the planet! |