IT SEEM TIMMING ITS WAY OFF, ANY IDEAS? TOMORROW I WILL OPEN THE ENGINE TO CHECK TIMMIMG MARK AND PROBLEMS INSIDE THE MACHINE, DOES ANY BODY HAVE TIMMIMG MARK DIAGRAMS? ANY SUGESTIONS BEFORE A TAKE IT APART? THANKS
Many things to consider but, let's try the simple things. You didn't say, so I am going to assume the mower is at least newish, not 30 years old. Let's say you have less than 300 hours on the engine. Let's further assume it worked last summer, or last week, but now it's acting up. Let's also verify the battery is in good shape and fully charged.
A mechanically functional (meaning all the internal parts are working, i.e. pistons, valves, etc) engine requires 3 things, air, fuel, spark. So the quickest way to start your diagnostics is to remove the cover over the air filter and then remove the air filter. I do not recommend spraying Quick Start.
Removing the air filter and placing the throttle at full speed, no choke, eliminates the "air" question. Dumping in the fuel eliminated all fuel related questions. What's left? Spark. If the engine fires and runs a bit, then dies, you have eliminated the spark question. The engine started so Spark and Air are good; you have to track down a fuel problem.
If the engine does not fire, you have eliminated the Air & Fuel questions; you must tract down a Spark problem.
Tracking down fuel problems.
Tracking down Spark problems.
If these simple steps do not solve the spark problem, you have a Spark problem that moves into the arena of complex. You will need to check coil gap and coil performance. If it still doesn't start you will need to diagnose the electrical system for wiring and safety switch problems, key switch problems, fuses, etc.
Once you get it running be sure to replace the Air Filter with a new one.
These simple steps solve most starting and running questions and problems.
SOURCE: Lack of Spark
If all of your tests are correct, the thing remaining is the ignition coil. A bit of a pain to get at and expensive too. Parts diagram here. Before you buy a new coil, see if there might be just a broken spark wire or loose connection at the spark plug contact end.
Mine was running fine driving 70MPH on the highway and just shut off. Now it cranks, fuel pump runs and it seems to be getting fuel but still no spark. I have a coil/module on order and will try it tomorrow.
UPDATE
Replaced the coil. Coil sparks once when you first turn the key on, that's it. crank sensor has already been replaced yesterday.
Injectors seem to fire (I smell fuel if I crank it a while) but still no spark.
I have 12V to the coil and 12V when cranking.
I see tons of posts with this issue but no resolutions. Come on somebody has to have been here before....
UPDATE #2
I do NOT have an injector pulse or a pulsed signal to the coil. When I crank the car the oil pressure light blinks on and off (just noticed this not sure if it is relevant)
I do get a check engine light when I turn the key on and when cranking, thought this meant ECU was good?
Any other way to test the ECU?
Could the pick up in the distributor be bad? Doesn't the pick up signal the ECU to fire the coil and injectors, I thought the crank sensor was just a TDC reference point?
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