QuestionOK, Daughter was driving home and engine just quit. she said it acted like it ran out of gas or just loss power. upon inspection it was almost out of OIL.(see below), had gas. engine does turn over but wont fire. I did hook up a OBSII the only code i got was lean fuel mixture. I could not get a code to popup on the dash. Timing belt?
recent history.less than a month ago 3/13/07 She let it over heat due to No antifreeze. spent $1300 for the following. replace head gasket on both banks, machine head and replaced, water pump replaced, thermostat replaced, coolant tube replaced, antifreeze replaced, oil and oil filter
AnswerHi Billy,
When you crank the engine, does the oil pressure light go off, and if there is a gauge does it move off of 0? If so then there is probably no problem due to low oil.
You could check the timing belt by removing the upper timing belt cover on the cylinder bank closer to the front of the car. Or check for the rotor on the distributor to turn, or perhaps look thru the oil cap to see if you can see movement of the valve train while a helper cranks it over, or feel the exhaust pipe outlet to see if it appears to be pumping air out which would indicate the valves are working. Because the timing belt had to be removed and reinstalled to do that earlier engine work, it is possible that they didn't replace the tensioner correctly, or they should have changed the belt and didn't and now it is broken, and thus the belt could have slipped/broken, so that would be worth checking by removing the three timing belt covers to observe whether the timing marks are lined up and if not, then the previous repair would be faulty and they would have to correct at no cost).
The lean mixture could be due to one of many possibilities:
restricted fuel supply line, inlet strainer on fuel pump clogged, fuel pump itself, fuel pressure regulator, an oxygen sensor (though that has a separate code) or its circuit or its heater, the throttle position sensor, the manifold absolute pressure sensor, the engine coolant sensor (that should read from 7,000 to 13,000 ohms between its two pins, located near manifold where the top radiator hose is attached to the engine, when the engine is cold, 70F, and that might have been damaged by the earlier experience), or the engine controller itself.
It might be an intermittant problem, but then of course when you try it again it will start were that the case.
I wonder if it might be the hall effect type sensor on the crankshaft or in the distributor for the cam shaft. These sensors often will begin to fail by breaking down when they get warm and then self-repair as they cool. So if it will start when you try it again, that may be the reason. Then you might just have to wait until it got bad enough to set a separate code (0720 or 0740).
Otherwise, it may be necessary to check all the items I listed above if it is only an issue of lean mixture. You can check those hall effect sensors by probing with pins inserted through the wire insulation, between the signal wire and the ground wire using a voltmeter. You turn the ignition to run and then crank the engine by hand with a socket on the crank pulley while observing whether or not you get a voltage altering from 5V to 0.3V or not as you turn it over. Let me know if you want the color codes for doing that test.
I wish I could help you more, but these are some ideas to consider. Please feel free to write back with the results of your investigation.
Roland
