TEST 2: Using Starting Fluid To Confirm Lack Of Fuel
Testing a ‘no-start’ problem, to see if it's being caused by a lack of fuel, with starting fluid is an old mechanic's trick.
The accuracy of this test depends on making sure that all 4 cylinders are getting spark. So, if you haven't already checked, you should check for spark first. If you get a ‘no spark’ test result from all 4 spark plug wires, then you can forget about the fuel pump being behind your 626's ‘no-start’ problem and you should focus your troubleshooting efforts on the ignition system.
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 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.
This is what you have to do:
- 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 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's hose clamp). - 3
Crank the engine once the air duct is back on and you're clear of the engine compartment.
- 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 test result tells you that the no-start problem is due to a lack of fuel.
Your next step is to check to see what the fuel pressure is with a fuel pressure test gauge. Go to: TEST 1: 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 1: Checking Fuel Pressure With A Fuel Pressure Gauge.
Where To Connect The Fuel Pressure Gauge Adapter
NOTE: The photo above is of a 1997 2.0L Mazda 626.
The orange arrow points to the banjo bolt that must be removed and replaced with the fuel pressure gauge fitting. This banjo bolt has two copper washers that seal against fuel leaks. As you're removing the banjo bolt, you need to be careful they don't fall down in the lower engine area. These copper washers are re-used when installing the banjo bolt back in its place (after doing the fuel pressure test).
Where To Buy The Fuel Pump And Save
The fuel pump in your 2.0L Mazda 626 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:
Not sure if the above fuel pumps fit your particular 2.0L Mazda 626? Don't worry, once you get to the site, they'll make sure it fits by asking you the specifics of your vehicle. If it doesn't fit, they'll find you the right one.
If this info saved the day, buy me a beer!
