QuestionI have a similar question to one I read earlier in regards to my fuel pump, it takes a while to start at times, it has a long crank and seems like the fuel pump is just not right. I have to turn the key for a good 3 to 4 seconds before i, thank you.t starts and sometimes the car while shake a little while idling at a stop light, not to mention my gas mileage has not been the greatest either. Can it be the filter needs to be replaced or do you think it is the fuel pump. Please advise
AnswerHi, Eddie. The most common cause of an extended crank time on your engine is a faulty fuel pressure regulator allowing the fuel pressure to bleed off back into the tank while the engine is not running.
I'd suggest also checking your fuel pressure to see if the fuel pump is operating properly and if the fuel pressure regulator is causing low fuel pressure while the engine is running. This will require installing an adapter in-line between the fuel line and fuel rail, and then attaching a gauge to the adapter. Read the fuel pressure with the engine idling, remove the vacuum hose from the fuel pressure regulator and read again, and last, momentarily pinch the fuel return line shut with a pair of needlenose pliers and note the pressure.
The first result is your normal fuel pressure. This should be about 44 PSI.
The second result is your fuel pressure on acceleration. This should be about 49 PSI.
The third result is the maximum pressure the pump is capable of delivering. This should be at least 70 PSI.
If you do not get a sufficient third result, start with the fuel pump. If the third result is okay but the others are low, start with the fuel pressure regulator.
It's unlikely that the issue is the fuel filter. Although this is an oft-neglected maintenance item, I've only once seen a fuel filter cause a vehicle to not run correctly. And in that one instance, it was a brand new non-factory fuel filter that did not allow enough fuel flow through it.
