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Cat Man
Cat Man, Cat Engine Expert
Category: Medium and Heavy Trucks
Satisfied Customers: 8620
Experience:  I am ASE Master Truck Certified.
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My 99 kenworth doesn't crank when turns on. When we charged

Customer Question

My 99 kenworth doesn't crank when turns on. When we charged the batteries and tries crank it smells like burn. What can it be?
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Expert:  Cat Man replied 1 year ago.
Hi. Thanks for asking your question and requesting me. I will try and help you out.
Can you get me the engine serial number please?
Are you saying it spins over but does not run? Or does it not even spin over?
Customer: replied 1 year ago.
Before it did spin over, but I tried to crank it so many times, that now it doent. It jut smells like burn.
Customer: replied 1 year ago.
Do you need the vin#?
Expert:  Cat Man replied 1 year ago.
Thanks for the information.
Does the yellow check engine light come on when the key is turned to the on position?
No not the vin. Just the engine serial number. I mainly want to know if you have a 40 pin ECM or a 70 pin ECM.
Customer: replied 1 year ago.
Yes, when I turn the key the engine lights come's on, but it goes away. Cat 3406E
Expert:  Cat Man replied 1 year ago.
Thanks for the information.
If the light is coming on. This indicates the ECM is receiving power and functioning.
When you say smells like burn, do you mean you can smell the exhaust?
Customer: replied 1 year ago.
No, the smell come from the front. It smells like a burning plastict.
Expert:  Cat Man replied 1 year ago.
I see. Thanks for the information.
There are several things I have seen cause a crank no start.
The first is low power to the ECM.
Second is the ECM is not getting an rpm signal.
Third is a faulty ECM.
Fourth is low fuel pressure.
And lastly is severely worn injectors.
I would try checking the AC to the injectors while cranking. You should have 20-40 AC while cranking. If you do not. You have either a low power supply, ECM problem, or no rpm signal. If you do have 20-40 AC. You have either low fuel pressure or worn injectors.
Please reply back if you need more help or have more questions. I am happy to assist.
Customer: replied 1 year ago.
I this problem last week and I gave it jump cables and put some start spray and I was able to cranked. But yesterday when I was trying fix a faulty bracker it would not crank
Expert:  Cat Man replied 1 year ago.
Thanks for the information.
If you were a me to get it to start with starting spray. I would not suspect a faulty ECM. When they are faulty. The engine will not run with starting spray.
However you still could have low power to ECM, an rpm signal problem, low fuel pressure, or worn injectors. While cranking the engine needs at least 35 psi to start. Checking the AC to the injectors while cranking is the best way to troubleshoot.
Please reply back if you need more help or have more questions. I am happy to assist.
Expert:  Cat Man replied 1 year ago.
Hey. I just wanted to see how things were going. Please let me know if you need more help. I am happy to assist.
If my information was helpful, please leave a good or higher rating so that I receive credit. Thanks!