I’m going to show you two different methods that you can use to verify if the No Start Condition on your 3.1L or 3.4L GM vehicle is due to a Lack of Fuel... which usually means that the Fuel Pump has gone BAD.
I have used both methods successfully and I’m going to share with you my experience in the form of step-by-step tests in this article.
Now, to give you specific details about this Fuel Pump Test, one involves using just Starting Fluid and the other involves using a Fuel Pressure Gauge. One method is a very accurate way of diagnosing a Lack of Fuel Condition causing a No Start... the other method is not that accurate.
Here are the contents of this article at a quick glance:
You know that gasoline is extremely flammable and that you have to be very careful... well, I’m going to remind you again... please, take all necessary safety precautions, be alert, be careful. Starting Fluid and gasoline can ignite very easily. You'll be able to accomplish both tests, indicated in this article, without any unhappy consequences, if you’re careful and use common sense.
Testing a No Start Condition, to see if it’s being caused by a lack of fuel can be very rapidly done with Starting Fluid. Now, let me tell you that this is not the most accurate way of testing the Fuel Pump... but it doesn’t mean it’s not effective.
I have used this Starting Fluid Test with good success, along with a few other tests, to verify if the vehicle I’m working on is not starting because no fuel is reaching the engine.
OK, to get this show on the road, this is what you’ll need to do:
Remove the Intake Air Duct from the Throttle Body. You don’t have to completely remove it, since you’ll have to reconnect it in one of the next steps.
Open the Throttle, manually, and spray Starting Fluid down the bore. When you have sprayed a good squirt of Starting Fluid, quickly reconnect the Air Duct to the Throttle Body (you don’t have to tighten the Hose Clamp).
Reconnecting the Intake Air Duct is important because your 3.1L or 3.4L Malibu (Venture, Monte Carlo, Grand Am, Century, Regal, etc) may be equipped with a MAF Sensor. Also, it’s a very important safety precaution in case you get a back-fire thru’ the Intake.
Once the Intake Air duct is back on the Throttle Body, have your assistant, inside the vehicle, crank the engine.
You’ll get one of two results with this test:
1.) The engine will start momentarily and after a few seconds will die or.
2.) The engine will only crank but not start at all.
OK, let’s find out what your results mean:
CASE 1: If the engine started and ran for a few seconds: This means that the reason your Skylark (or Impala, Lumina, Monte Carlo, Achieva, Alero, etc.) is not starting is due to a lack of fuel.
Usually, this also means that the Fuel Pump is BAD. But since we don’t live in a perfect world... this could also mean a few other things like: the Fuel Pump Fuse is Blown, or the Fuel Pump Relay is BAD. Now, don’t worry about this too much, because you can test this by:
Removing the Fuel Line that connects to the Fuel Injector Rail (this is the one that delivers Fuel from the Fuel Filter) and place it in a container. When ready, have your helper bump the starter motor while you verify if Fuel comes out or not. No Fuel coming out of the Fuel Line further confirms a BAD Fuel Pump.
Making sure that the Fuel Pump is getting power (12 Volts) when you crank the engine.
You can accomplish this by locating the wire (circuit) that feeds power (12 Volts) to the Fuel Pump and with a Multimeter in Volts DC Mode, verifying that 12 Volts are reaching the Fuel Pump when you crank the engine.
CASE 2: The engine did not Start, not even momentarily: This usually means that a Lack of Fuel IS NOT the reason your car is not starting.
Now, remember what I said about this test not being very accurate? Well, I suggest you do one more test...
... This is to remove the Fuel Line that connects to the Fuel Injector Rail and place it in a container. Then have a helper bump the starter while you check to see if Fuel comes out of the Line and into the container. This way, you can visually see if there is or there isn’t fuel coming out of the Fuel Line.
A No Start Condition can be caused by a number of things (yeah, I know, life’s a bitch)... so my recommendation is to see the other articles I’ve written to further help you in your quest, go to Related Articles.
“Some people see things that are and ask, Why? Some people dream of things that never were and ask, Why not? Some people have to go to work and don’t have time for all that.”