TEST 2: Using Starting Fluid To Confirm Lack Of Fuel
Another way to find out if a lack of fuel is causing the engine to not start, is to do a starting fluid test.
This test simply involves spraying starting fluid into the throttle body and then cranking the engine to see if it starts.
If the engine is not starting due to lack of fuel, spraying starting fluid will make the engine start. Although it will only start momentarily and then stall.
IMPORTANT: The only way to get a correct test result from the starting fluid test, is to make sure that all eight spark plug wires are sparking. So if you haven't checked for spark, you must do it before doing the starting fluid test.
IMPORTANT: This is a very fast and easy test but you do have to take one very important safety precaution and this is to reconnect the air intake duct back to the throttle body after spraying starting fluid down the throttle bore (although you don't have to fasten it). This will prevent any backfire, that might occur, from scaring the heck out of you when cranking the engine.
These are the test steps:
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 plate and spray starting fluid down the bore.
As a safety precaution reconnect the air duct after you have sprayed a good squirt of starting fluid (but you don't have to tighten the air duct).
Crank the engine once the air duct is back on and you're clear of the engine compartment.
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 test result confirms that a lack of fuel is keeping the engine from starting.
Your next step is to check to see what the fuel pressure is with a fuel pressure test gauge. Go to: TEST 2: Checking Fuel Pressure With A Fuel Pressure Gauge.
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 and this is to check the fuel pressure with a fuel pressure test gauge. Go to: TEST 2: Checking Fuel Pressure With A Fuel Pressure Gauge.
Where To Buy A Fuel Pressure Test Gauge
You can buy a fuel pressure test gauge just about anywhere and is one of the most important tools any serious DIY'er should have in his/her tool box.
The following fuel pressure test gauge kits are pretty good deals and will work with your 5.2L Jeep Grand Cherokee:
All of the fuel pump pressure test kits above have the fitting that will connect to your Jeep's Schrader valve.
More 5.2L Jeep Grand Cherokee Tutorials
You can find a complete list of 5.2L Jeep Grand Cherokee tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Do An Engine Compression Test (1993-1998 5.2L Jeep Grand Cherokee).
- How To Test The Camshaft Position Sensor (1993-1997 5.2L Grand Cherokee).
- How To Test A Blown Head Gasket (1993-1998 5.2L Grand Cherokee).
- How To Test The MAP Sensor (1993-1996 5.2L Grand Cherokee).
If this info saved the day, buy me a beer!