Have Jeep Questions? Ask a Jeep Repair Expert for Answers
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Hello and sorry for the delay! YES, we sure can.
Let me ask you this, if you disable the fuel system, does the engine start and run using starting fluid?
Hello and sorry for the delay! If the engine does in fact have spark but does not run on starting fluid (after disabling the fuel system), the engine is simply out of time. Hands down.
So, basically, we need to figure out of the ignition timing is off or if the valve timing is off. Does that make sense?
Very good question. I will explain..
Because you have spark, no.. the problem is not going to be the cam or crank sensor..
YES, the problem is caused by the valve timing being off or incorrect. This basically confuses the computer causing the ignition timing to be off.
The computer is not firing the ignition system at the right time because of fualty inputs. The cam and crank signal inputs. However, it is not the sensors. The signals from the cam and crank sensor out of sync with eachother because the valve timing is off.
Does that make sense?
Reseting the computer will not get this thing started.. at least in my experience. However, you can sure try. In addition, replacing the computer will not help either. The new computer will act the same way.. again, it is because of the faulty inputs to the computer. What do we know about computers? Garbage in, garbage out. Thats how they work. YES, the cam or crank trigger wheel can in fact be damaged affecting the inputs to the PCM. This will affect the signal coming from the cam or crank sensor as the engine is cranking over.
So, what you need to do is pull the front cover apart and double check the timing marks and the cam trigger wheel for damage.
That is your next step.
Sounds good. Good luck!!!
Here is a picture.
When the number 1 piston is at TDC, the cam marks should look like this..
In addition, even if these timing marks are lined up correctly, the camshaft(s) could be out of aligment with the crankshaft.
For example, if one of the camshaft sprockets has spun on the camshaft, the timing marks will be dead on and the cam will be out of rotation in relation to the crankshaft. That is why you hear the combustion happening from the intake or exhaust when trying to start the engine.
That is why we should talk on the phone. We could have covered all of this by now. Anyway, to answer your question, the dowel pin between the camshaft sprocket and camshaft could have broke or sheared causing the sprocket to spin on the camshaft. The ingition timing is not off in relation to the crank. It is off in relation to the cam(s)
I can talk in about 10 minutes. Does that work?
Going to log off now. Please accept my offer and call me.
Hello and sorry for the delay! I have been visiting a family member in the hospital. YES, anything that can damage or affect the signal going back to the computer (cam or crank signals) can cause a no start condition like you are describing.