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Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Dodge
Satisfied Customers: 1513
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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I swapped my 2001 4.7 dodge Dakota with a 2003 4.7 dodge ram

Customer Question

I swapped my 2001 4.7 dodge Dakota with a 2003 4.7 dodge ram and it cranks but doesn't fire
Submitted: 10 months ago.
Category: Dodge
Customer: replied 10 months ago.
Posted by JustAnswer at customer's request) Hello. I would like to request the following Expert Service(s) from you: Live Phone Call. Let me know if you need more information, or send me the service offer(s) so we can proceed.
Expert:  Juan Crespo replied 10 months ago.

Hi there. Welcome to our site!

I’m a retired master technician and tech instructor with over 30 years experience. I also have access to a pretty good database on automotive service and repair. However, if you’re thinking on working on the vehicle yourself, all my knowledge and resources won’t help you if you…

… don’t have tools or the skills to use them

… don’t know there will probably be some special tools and equipment needed for a proper diagnosis

… don’t realize it may take a few back and forth replies to solve the issue

… don’t understand that I will need you to provide specific information

Is your Dakota equipped with factory alrm and immobilizer? Do you have the original key with a Gray molded rubber cap?

Customer: replied 10 months ago.
It has a factory alarm I have the original key
Expert:  Juan Crespo replied 10 months ago.

Thank you for that information. 2001 and 2003 4.7L engines should be compatible - changes happened in 2004. So, if the original harness fit the newer engine and everything else is OK, there should be nothing other than the alarm/immobilizer preventing the engine from starting and running. Is there anything else that you removed or replaced, like the ignition switch, or any of the alarm components? Is the security light ON in the dash?

Customer: replied 10 months ago.
Someone said that my crankshaft sensor could be different between the years
Customer: replied 10 months ago.
no nothing else was replaced and no there is no security light on on the dash
Expert:  Juan Crespo replied 10 months ago.

Actually whoever told you about those engines having a different crank sensor was absolutely right. Not only the sensor, but the tone ring as well; the 2003 has 32 teeth and the 2001 only 16. Those are incompatible and the only way you could use the newer engine in the older car woul be to yank the crankshafts out and swap the tone rings.

Up to 2001, Chrysler used 2-plug Single Board Engine Controllers (SBEC). They went to a 4-plug new generation controller (NGC) in 2003, so none of the Powertrain components are compatible either.

I'm really sorry it fell upon me to be the bearer of such bad news. Please let me know if there is anything else I can do.

Best Regards.

Customer: replied 10 months ago.
if I swap those it should run
Customer: replied 10 months ago.
Or could we possibly flash the computer to match that engine
Expert:  Juan Crespo replied 10 months ago.

I know the harnesses are different but can be made to fit. Regarding the engines themselves,there might be other differences depending on VIN. Do you have both yours and the donor's?

Customer: replied 10 months ago.
No but I can get it both
Expert:  Juan Crespo replied 10 months ago.

Why don't you that and I'll check to see if there are any other surprises.

Best Regards.