Testing the Fuel Pump Ground signal The best way to check the fuel pump ground is with a multimeter and measure the voltage drop across the ground side of it. If there is not enough power (typically 12 volts) to the fuel pump due to a poor ground. Start with the multimeter on the voltage setting, with the positive lead touching the battery's positive post. Next move the negative lead to fuel pump ground wire which is usually bolted to chassis. Close to 0 volts, you should see a drop in voltage. Anything over 0.2 volts reveals resistance that is too high, which means the ground wire has a problem.
This percentage is high for fuel pump grounding problems, but these issues do happen and will cause the fuel to work less than perfect or it will make the pump not work at all. Fuel pressure below the required 40-60 PSI can lead to engine stalling or hard starts by a weak ground connection causing pump cycle interruption A ( this type of condition only makes mention in the CID/26, other trouble code like fuel p287A system series too rich banks being one of many ).
Ground connections that are corroded or loose in some way is a common cause of the issue. Over time, it is possible that the installation location of the metal contacts allowing connection between ground wire and vehicle’s chassis might experience a weakening process caused by moisture and/or road salt which may lead to high resistance. To avoid this, mechanics recommend cleaning the sweat points at 30k miles. Grounds can be maintained by removing corrosion with sandpaper or a wire brush and applying some dielectric grease.
One memorable example was a recall by a large maker that traced its problems to inadequate grounding of the fuel pump in 100,000-plus vehicles. The bad ground meant the pumps would sometimes shut down, which resulted in the truck stalling frequently and it not making much if any power at all under load.
To quote the great Thomas Edison — “the value of an idea lies in the using of it. For things like fuel pumps maintaining a good ground is paramount to running well and not failing costly parts.
The costs of repairing this common grounding issue are low, ranging from $50 to $200 depending on the extent of corrosion or damage. Not attending to these Through a $500-$1,000 repair of DI-beta higher mileage and/or poorly- maintained vehicle fuel pump.
So to sum up, you must verify your fuel pump grounding. A basic multimeter test can help you identify whether the ground connection is solid or if corrosion and resistance has made its paws in. For more about fuel pump testing and maintenance, go to Fuel Pump.
