Hi, For about a year my car (93 Subaru Legacy) just dies while driving: uphill, downhill, flat doesn’t matter. It has 185,00 miles. It’s like it’s running out of gas. I pull over, let it sit about a minute, start up and drive off. This can happen multiple times. My mechanic isn’t sure what to do. We’ve replaced the fuel pump and the ground cable. I’m in AZ so humidity isn’t an issue. Any help would be appreciated.
Thanks, Warren [RevAvery@yahoo.com]
When was the fuel filter last replaced?
If you don’t know the answer, then it is due.
The fuel filter should be replaced every 30k miles, but it is possible to need replacement even sooner if you have had “dirty” gas on a few occasions. If your mechanic has not even considered the possibility of a clogged fuel filter, then I have to question his diagnostic abilities.
Incidentally, it is possible that the fuel pump needed to be replaced because it had to try to force gasoline through a partially-clogged fuel filter. One of the best ways to kill a fuel pump is to ignore the 30k regimen for fuel filter replacement.
The ignitor may be intermittent so changing it out may fix the trouble. If the ignition system isn’t working when the trouble occurs I would try that.
Heat sensitivity is more often than not an ignition component problem. Buy a spark tester and check for spark when the stalling occurs. I’ll bet you have none.
The two components most likely to become heat sensitive are the igniter (as Cougar suggested) and the coil (coilpack).
But any component containing windings is a possible suspect, including relays. The windings in coils are coated with a varnish-like substance that loses its elasticitty as it’s thermally cycled over time. Fractures form in the insulation that open up when the coil wire is heated and expands and short the coil windings out, making the component less than effective.
If your mechanic put the ignition wires on a scope and judiciously used a heat gun I’ll bet he could find the problem. If it’s coil windings he’ll probably even see the voltage spikes drop as the windings become less effective.
Does it make a difference if the gas tank is full or empty? When it does this, pull over and open the gas cap, does it make a sucking sound when you open it? If it does, perhaps you have a venting problem in your fuel system and it’s not letting any air in as your gas level goes down. (First check or change the fuel filter.)
Symptoms don’t quite fit, but any chance your catalytic converter is disintigrating and is plugged up?
Hi, Thanks so much for the replies. It appears that there are problems with the camshaft and crankshaft sensors causing a stall on these vehicles. Others have had the same problem. I’m in the process of getting this done. Thanks again, Warren