Question1998 Cadillac Seville STS, Northstar 300 HP Engine
What could be the cause of hard starting? At times, after being run and sitting for 30 minutes or more it will crank for 7 - 10 seconds before starting. Also, at times, after sitting all night the same problem occurs.
Repairs: Spark Plugs and wires replaced; Fuel pump replaced; injectors removed, cleaned and reseated, Engine Control Module removed, sent for testing and module sensing crank position replaced.
Local Cadillac Dealer and current mechanic can't find problem. No codes or engine malfunctions indicated on scanners.
AnswerCould be the FUEL PRESSURE REGULATOR. You need to put a gage on the fuel line to see the pressure.
It could be the fuel pump relay that is not working:
Fuel pump test:
1. Get yourself a helper.
2. remove the gas cap.
3. have one person listen in the gas tank at the gas cap opening.
4. have the other person turn the ignition switch to the ON position ONLY so as the dash lights come on. Do NOT attempt to start the engine.
5. As soon as the ignition key is turned to the ON position, The person at the gas tank should hear the fuel pump run for TWO SECONDS and then it should STOP.
6. Does it ?.
7. If it does NOT run for the 2 seconds the fault is either the fuel pump or the fuel pump relay.
8. You need to put a fuel pump gage on the fuel line to be sure your getting sufficient pressure.
