Longer Than Usual Crank Time. Please Help!

[Maty]

Hi, I recently bought a '01 Grand Prix with a 3.1 V6. When I bought it I noticed a longer than usual crank time, about 4-6 seconds, and the guy that I bought it from (a mechanic) told me that he took out the fuel screening from the fuel pump (it was a new pump, he just got "bad gas") and put a one-way valve instead, because of some clogging, and said that that was the problem. I got a fuel screen from a junker since they don't sell it separately and already put it in place, but the problem is still there, a long crank time.

I checked the fuel pressure regulator, the test where you take the hose out while running and look for any leaking and nothing happened. I'm assuming it's a fuel problem and not air or spark, but I am really not sure.

The problem happens when I leave the car over night or just sitting for a while. Also putting the key in the "on" position and letting it sit there for couple of seconds before starting doesn't cure the problem. Please help me out. Any help is appreciated, thanks.

[Tech II]

This sounds like a classic fuel pump relay problem, but unfortunately not on your car....

On older cars, the oil pressure switch use to be in parallel with the f/p relay circuit......so if the relay failed, you would have an extended crank until the oil pressure closed and the the car would start.......however, on the newer cars, they don't have the oil pressure switch in parallel anymore.....

the guy that I bought it from (a mechanic) told me that he took out the fuel screening from the fuel pump (it was a new pump, he just got "bad gas") and put a one-way valve instead, because of some clogging, and said that that was the problem. I got a fuel screen from a junker since they don't sell it separately and already put it in place, but the problem is still there, a long crank time.

I am a little confused here....does your car have an external fuel filter? If it doesn't, then the fuel filter is built into the pump in the tank....

If it has an external fuel filter, then the pump module has what is called a fuel "sock"....is this what he removed? If so, why? And the only reason for installing a one way check valve, which would be after the pump, would be to retain pressure, due to a fuel leak in the pump itself(not maintaining pressure with the key on).....sounds like a "mechanic", not a technician, trying to mickey mouse something, to me...

First place you start, is a fuel pressure switch....put a gauge on the schraeder valve on the fuel rail.....turn key to "on"(don't crank), and what is the pressure?...does it immediately go up to 40 psi? Does it hold or drop?

If it holds, but is low pressure, turn key to "off", wait five seconds, then turn key to "on" again.....does the pressure rise? If it does, cycle the key again several more times until you get max pressure(what is it?)......now try and start the car......does it start quicker with more pressure on the gauge?

If you have low pressure from the test, and it slowly builds up as you cycle the key without starting the car, AND you have an external fuel filter, I would replace that fuel filter first....

If pressure is low, and you don't have an external fuel pressure, you may need a pump module....

[SleepyHead98]

I got a 3.1 L, 233k on it. What mileage does your engine have? What does your check engine light say? I bet I can figure out whats wrong with your car.

[Maty]

Thanks for the replies. It does have an external fuel filter under the car through the fuel lines. And from the pictures I've seen of a fuel sock, it is that that I'm talking about. He removed that and replaced it with a one-way valve. It was on the fuel pump, on the outside, on the very bottom of the entire fuel pump assembly.

I did the fuel pressure test and the very first time (after car sat for a while) I had 25 psi on the first reading with the key "ON" position. It hit 25 and started to drop. Turned it off and waited the 5 seconds, second time it went up to 52 psi and started to slowly drop. Every time after that I got 52 psi, I only waited a couple of minutes between intervals, not a overnight thing. When I started the car it went up to 42 psi and held there, I'm not sure if it rose fast or not, didn't look at that.

It has 146k miles and there is no "Check Engine" light on.

[Tech II]

Well, we can assume this "mechanic" felt that the fuel pump was leaking, that's why he put the check valve on.....but by doing that he removed the first line of defense for the fuel pump......that sock prevents anything in the tank from being sucked into the pump, and causing problems...and putting the check valve did not prevent the the pressure from dropping...

So if you cycle the key 3x's, pressure gets to 52 psi....then it starts without delay? Then you can start it this way , start it with a delay, or fix the problem.....

To fix it, you have to find the leak....but not easy because you need special tools.....I believe you have plastic fuel lines going to the fuel rail......if they were rubber, you could just clamp down on them .....but you can't do that with plastic lines.....the special tools you need are shutoff valves that you insert into the supply and return lines.....

With the valves installed, you get max pressure on the system by cycling the key several times, then you shut off both valves.....

If pressure drops, you know you have a leaking injector.......

If pressure holds, you open the return line.....

If pressure drops, you know you have a bad regulator.....

If pressure holds, then you open the valve on the supply line....if pressure drops, you look for an external leak in the line to the tank.....if there is none, then the problem is in the tank, usually the fuel pump.....

The fuel pump could be damaged, because it has no sock......the pump itself could be in question, because it was replaced and you don't know what brand it is.....most aftermarket pump are not as good as OEM's.....

[Maty]

Is there any way to check the fuel pump directly?

Also by putting the ignition on "ON" 3x's does help a little bit, but not a lot. It probably shortens the cranking from 6 seconds to maybe 4 or 5.

But I'll try those steps and see what results I get, thanks a bunch. Really appreciate it.

[Maty]

Scratch that, putting the ignition on "ON" several times doesn't help at all. Today, I kept doing it and in one of the instances it even took longer than normal. It seems like it's taking longer and longer to start each time.

[Tech II]

Something simple to try, is replace the external fuel filter......