Why won’t my car start?

Question:

I have an oddball problem which is rapidly becoming an annoying situation. One of my vehicles is a 1994 Pontiac Sunbird with a 2.0-liter 4-cylinder engine and a 5-speed transmission.

One day I was running errands with the car and parked it in front of a store. When I came out and started it again, it ran, but once I began driving it, I noticed it lacked power to some degree. It was not dramatic by any means, but it was noticeable. I drove it that way for a few miles until I got to my next destination. I shut the car off, and when I came out and started it up again, it ran, but it ran horribly. I shut it off immediately and tried to re-start it, and it would not kick over. It cranked well enough, but would not start. It seems it got progressively worse after being shut off a couple of times and then re-started. I have no idea what that implies, but I began looking things over trying to narrow it down. I have checked a number of things on the car trying to track down the issue, and I’ve had zero luck.

There is spark, the fuel pump is operating properly (and the pressure is within specifications), there is no obstruction in the induction system and the air filter is clean, the catalytic converter is not clogged, the ignition module/coil pack assembly (a year-specific and model-specific unit) was changed, the ECM was changed, the crank angle sensor was changed, and there are no obvious problems in the wiring. In addition, the “check engine” light never came on for any reason (and, yes, the indicator light itself does work). I have also checked the spark plugs after cranking the motor a few times, and there was a bit of gasoline on them, indicating that the injectors are putting at least some fuel in the chambers. I have also sprayed starting fluid into the throttle housing and cranked the motor, only to find that it still would not fire up.

There are no apparent abnormalities elsewhere which may be the source of the fault—at least, none which are obvious to me. In case you’re wondering, the timing belt is only a few thousand miles old and is still in one piece (I checked that as well). I have no idea where to look next.

There is another peculiar thing I’ve noticed and perhaps this will be a telling clue. When I first try starting it, the motor “kicks” over like it is about to start, but fails to. Then, it simply cranks continually and gives no hint of actually running on its own. If I come out the next day and try it again, the same thing happens. It sputters once like it wants to start, and then fails to. It just continues to crank. I wonder what difference waiting for a day makes. What gives? There is compression, spark and fuel, but apparently the car is unwilling to go on living. Any help will be VASTLY appreciated!

Answer:

If you have good compression, good spark, and good fuel delivery but the engine still won’t run then the problem may be one of timing.

If the compression, ignition, and fuel delivery are each good individually but not correctly synchronized with each other then you will get no joy. Have you checked the ignition timing?

Finding some gasoline on the spark plugs after cranking the engine over a few times is not the best test of whether the car’s fuel system is working correctly. You should measure fuel system pressure at the Schrader valve on the fuel rail if you haven’t already. You can have the fuel injectors tested by a shop with the requisite equipment.

It’s also possible, and perhaps more likely, that there’s something amiss in the ignition system. Even if the fuel pump or injectors have failed, or if there’s an obstruction in the fuel system preventing fuel from getting to the cylinders, the engine should have fired if all else is OK when you sprayed starting fluid into the throttle housing, unless there’s an obstruction in the throttle housing that prevented the starting fluid from getting into the cylinders. You state that there is spark but don’t say how you determined this.