QuestionQUESTION: first I sent you this question : details. counter balance belt broke..timing belt jumped. lots of damage incurred. put salvaged head on(had it checked out by a machine shop)new pistons rings bearings and new crank shaft position sensor.. car has 84k on it.. when you turn the ignition on the check engine light comes on for a little while than goes out like it should.. the crank sensor has 4.95 volts and 12volts going to it.. I'm getting no spark..the code reader gives PO335 when you turn the car over. could the new crank sensor be bad and is there a way to check it. the engine is getting gas but no spark.. In you answer.. to me you gave me 3 questions..here are the questions and my answers.. 1st. you asked How did you verify you don't have spark? I pulled plugs one at a time and coil lead and checked new plugs against ground while cranking engine. 2nd question you asked me.. when you say you're getting gas does this mean that the fuel pump provides pressure or that the injectors are firing? how did you test? I pulled spark plug.. plug wet with gas... 3rd question you asked me Did you clear the PO335 and have it return after doing the work? Yes 3 . 4 . maybe five times. cleared the code reader and disconnected the negative on the battery for five minutes or more every time to clear the computer. same code returned every time.. Is there a way to check the crank position sensor.. or do you have more questions not sure were to go from here Jim in Nebraska
ANSWER: Thanks, Jim.
Since you cleared the code and it returns, it's pretty safe to presume there's some sort of problem with the crank sensor signal. You'll need an oscilloscope to check the crank sensor properly, and you'll need a voltmeter capable of reading ac voltage and frequency to do a halfway check.
Your spark check sounds conclusive, but I'm not convinced that the injectors are necessarily firing. The wetness could be from the assembly of the engine.
I'll need to know the year and model of your car as well as what engine you have to give you further advice on how to proceed. (Sorry. I should have indicated that in my previous response). With that information, I can give you information on how to test the crank sensor by the wire colors in the connector, and advise as to what to check that may be damaged or have occurred in the reassembly that would cause a crank sensor problem.
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QUESTION: Thanks for replying so quickly.. I had a feeling I was forgetting something.. the car is a 2000 Sonata 2.4L 4cyl.
.. oh and as for the gas on the plugs you could smell it in the cylinder and on the the plug.. it was getting fuel.. thanks again .. Jim in Nebraska
AnswerI'll start with the instructions for checking the crank sensor. With the key on and the sensor unplugged, check the voltage between the pink and black wires in the harness end of the connector. You should have battery voltage. If not, you'll need to check the power (pink) and ground (black) circuits. If that's okay, reconnect the sensor and check the yellow wire for signal while cranking. If you have a scope, this should be a 12V square wave. If not, check with an AC voltmeter. I'm figuring the voltage reading should be about 8.5V. Also check for frequency. You should get one when cranking the engine.
Also, the following are problems that can occur with this repair:
1. Plate between crankshaft sprockets is damaged or installed backward.
2. Crankshaft sensor is installed backward. (The plate should run between the two halves of the crank sensor).
3. Sensor wiring is not routed exactly as orignally and is grounding on the engine or has rubbed through.
4. Camshaft timing not proper.
And as an afterthought, since your cylinder head was off, is the ignition failure sensor plugged in? It bolts onto a plate on the transmission end of the engine near the rear camshaft.
