FUEL PUMP TEST 2: Using Starting Fluid
Using starting fluid, to confirm a lack of fuel condition causing a no-start problem, is a very old troubleshooting technique. But, using it to check for bad fuel pump on your GM vehicle (which is equipped with the Passlock Anti-Theft System) still requires that you check the fuel pump with a fuel pressure gauge.
Yep, I hate to say this but your vehicle's factory anti-theft system complicates the result of the starting fluid test. This is due to the fact that the factory anti-theft system (Theft Deterrant System) on your car can mimic a failed fuel pump.
The starting fluid test won't be able to tell you whether the lack of fuel problem is caused by an anti-theft system problem or a bad fuel pump. So, to repeat myself, this means that you still have to do a fuel pressure test (to check the fuel pump).
The starting fluid test still has its merits. Because it is a good way verify if the no-start problem is due to a lack of fuel condition (either due to a bad fuel pump or an anti-theft problem). But if you want a faster and accurate fuel pump test result, start with: TEST 1: Fuel Pressure Test With Gauge.
OK, to get this show on the road, this is what you'll need to do:
- 1
Remove the intake air duct assembly 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.
- 2
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 assembly is important because your 2.4L Ecotec equipped vehicle is equipped with a MAF sensor. Also, it's a very important safety precaution in case you get a back-fire thru' the intake. - 3
Once the intake air duct is back on the throttle body, have your assistant, inside the vehicle, crank the engine.
- 4
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 confirms that your vehicle's no-start problem is due to a lack of fuel. The only problem is that this could be due to either an anti-theft system component failure or a bad fuel pump.
I suggest that your next step be to test the fuel pump's fuel pressure with a test gauge. For this test go to: TEST 1: Testing Fuel Pressure With A Fuel Pressure Test Gauge.
For more info about an anti-theft system failure go to: Is The Anti-Theft System Causing The No-Start Condition?
CASE 2: The engine did not start, not even momentarily. This test result is very inconclusive. So, your next step is to check the fuel pump pressure with a test gauge. For this test go to: TEST 2: Testing Fuel Pressure With A Fuel Pressure Test Gauge.
Is The Anti-Theft System Causing The No Start Condition?
Your vehicle comes equipped with a factory anti-theft system. This system is very, very problem prone as the car ages. Eventually, the anti-theft system will cause your car to crank but not start.
When this happens, the resulting no-start problem will make you think that the fuel pump has failed. Yep, that's right, the anti-theft system failure usually mimics a failed fuel pump.
To explain this a bit further, the anti-theft system is designed to disable the fuel injectors (when it activates) 3 seconds after the engine starts. So if you use starting fluid (while the engine is being cranked), the engine will start (and of course die when the dose of starting fluid you just sprayed gets consumed).
The following chart should help you figure out if the anti theft system is one behind your engine's no-start problem:
| Anti-Theft Versus Fuel Pump | ||
|---|---|---|
| Symptom | Anti-Theft | Fuel Pump |
| Engine cranks but won't start | YES | YES |
| Engine starts with starting fluid (momentarily) | YES | YES |
| Ignition system delivers spark | YES | YES |
| Anti-theft MIL flashes on instrument cluster | YES | |
| Engine starts momentarily then stalls | YES | |
| Fuel pressure at spec (as checked w/ fuel pressure gauge) |
YES | |
| PCM disables fuel injectors a few seconds after the engine starts |
YES | |
Where To Buy The Fuel Pump And Save
The fuel pump in your 2.4L Ecotec equipped GM car is located inside the fuel tank. The fuel pump can be bought in any auto parts store, but I think you'll find the better price online. The following fuel pumps are pretty good deals:
If this info saved the day, buy me a beer!
