Using Starting Fluid
When I started working on cars, most vehicles rolling around had carburetors. I entered this field when vehicles transitioned from carburetors to electronic fuel injection.
And the go-to test for diagnosing an engine no-start problem (due to a bad fuel pump) on carbureted engines was the starting fluid test.
The cool thing is that the starting fluid test still has its place in diagnosing modern fuel-injected vehicles.
I've used the starting fluid test on many modern electronic fuel-injected vehicles to diagnose an engine no-start problem caused by a lack of fuel.
Although the starting fluid test isn't the most accurate way to test a fuel pump, it will point your engine no-start diagnostic in the right direction.
Let's get testing:
- 1
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. - 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 is a very important safety precaution in case you get a back-fire thru' the intake manifold. - 3
Crank the engine once the intake air duct is back on the throttle body.
- 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 analyze your test result:
CASE 1: The engine started and ran for a few seconds. This result confirms that the engine isn't starting due to a lack of fuel.
I suggest that your next step be to test the fuel pump's fuel pressure with a test gauge. For this test go to: Using A Fuel Pump Pressure Tester To Test The Fuel Pump.
CASE 2: The engine did not start, not even momentarily. This result generally tells you 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 and this is to test the fuel pump's fuel pressure with a test gauge. For this test go to: Using A Fuel Pump Pressure Tester To Test The Fuel Pump.
More 3.1L Chevrolet And Pontiac Diagnostic Tutorials
You can find a complete list of 3.1L Chevrolet and Pontiac Diagnostic tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Test The TPS (1990-1994 3.1L V6 Chevrolet And Pontiac Vehicles).
- How To Test The Alternator (1990-1994 3.1L V6 Chevrolet And Pontiac Vehicles).
- How To Test The Engine Compression (3.1L V6 Chevrolet And Pontiac Vehicles).
- How To Test The Starter Motor (1990-1994 3.1L V6 Chevrolet And Pontiac Vehicles).
If this info saved the day, buy me a beer!
