Strange starting / fuel problem

[Tempest]

99 Ranger 4.0 OHV, no mods.

Truck was starting at the flick of the switch, then it started to take several seconds. Checked the battery...bad. Replaced battery with Duralast Gold...battery still good...problem is still there as well.

Changed the fuel filter with a WIX...no improvement.

I checked the fuel pressure. Goes to ~10-20psi when key is turned (but not started) for about 1-2 seconds, then there is an audible click (relay I believe), and the pressure drops like a rock. Will build up more pressure with multiple cycles. The pump does go off with this click.

Now the strange part. The truck will start and seems to run fine once there, BUT the fuel pressure is at a steady 65psi no matter the RPM. The book calls for 35-45psi.

So I think fuel pressure regulator. Replaced it with an OEM part...no change.

And there is vacuum at the control hose.

Any ideas??

And is the fuel pump supposed to click off after just a few seconds with the power on?? I thought it was supposed to stay on once the key was turned?

Thanks.

 

[brianl703]

If you turn the key to ON but don't start the engine, the fuel pump will run for only about two seconds.

 

[punisher]

I would verify my fuel gauge is not screwed up.

With a good fuel gauge hooked up cycle the key several times while keeping an eye on the pressure gauge. The pressure should level off and remain steady for at least 30 seconds. If it(pressure) is dropping off, the fuel pump ck valve is the main suspect. That is cause #1 for excessive crank times on that vehicle. With the engine idling, unplug the vac line to the pressure regulator, you should see a 10 psi jump. brianl703 is right about the relay operation.

Pull codes and ck for a cam position sensor code as well.

 

[Donald]

The fuel pump only stays on for a few seconds unless the engine starts. Its a safety issue in that you do not want the fuel pump pumping gas all over the place after an accident. So there are a few ways they handle this, some look for oil pressure and shut off fuel pump if no oil pressure, also there is an inertia switch.

 

[tc2468]

I would suspect the fuel pump check valve.
I would also check your (TPS)throttle position sensor and make sure its within spec.
The TPS maybe giving a flooded engine status causing fuel to be cut off to your injectors.

 

[TallPaul]

I just had a fuel pump die. When they replaced it they installed a Carter new pump. It would not work. Another Carter worked. Then next day it was hard starting, but fine once running. I would have to key prime 5 or 6 times to get it started. Even then it was rough. This went on for a week or so before I could get back to the shop. They said the second Carter was no good. They tested the press regulator and it was okay. The pump would get abouty 20 psi first key click, then go higer each click to about 50. Once running it would settle around 40 psi. Yesterday they installed a Motorcraft pump and it is starting fine now.

Hope that helps shed light on your problem. Seems your pump could definitely be the problem.