hey ok first thing does the 2006 4.7l 1500 slt rams have a variable cylinder firing to save on gas? Second i think i might have a issue with the tach it reads 0 rpms at 40 mph, and only jumps to 6000rpm when i floor it. Has anyone had that happen to them, oh and it stays at 0 rpms when just accelerating normally.

Plz help if u can

 

How about cleaning the battery terminals and checking the grounds... You'll also get a reboot from having the battery disconnected.

 

do you have a check engine light on by any chance?

 

No you do not have MDS in a 4.7 engine.

Bad tach or bad crank sensor...

 

well now it works and i didn't do anything. the car is parked during the day and i start it at lunch time to eat my lunch and drive home then drive back to class which isn't very far from my home, now after class it starts working grrrr wtf..... i think it might be a loose connection or something like that because if it gets over the 90s it stop working right and with i get up to go to work at 5am it works but after that it starts to act up again hmm any ideas where that wire or sensor would be so i can check it out to see if my the heat is make the connect expand and get loose...


thx for the replies

 

I have the same problem except...it started several months ago and has progressively gotton worse. Now it has this problem all the time. I have run the instrument cluster self check and the tach will read either 0 or 6000 depending on the step of the self check. This is all the troubleshooting I have done to this point. I have read on some forums that you may need to clean the contacts of the connectors on the back of the instrument panel but have not tried that yet. I do not believe it is a issue with the ground on the battery since everything else works fine. I will disconnect the battery tonight to see if the problem resets (goes away) but not holding much faith in that working. My best guess is a bad tach.

 

Also, like Hammer said a couple days ago. You may also have a bad crank sensor.

 

Is there a way to check the crank sensor? Or do you just have to replace it to see? I would think if the tach fails on the instrument panel self test (as with my case), it would not be the crank sensor. If it passed the self test, I would look at something like the crank sensor. Just my thoughts.

 

How do u do the self test and i will check this weekend if the connector in the back of the panel is loose but if u find anything else out let me plz

thx for the replies

wize

 

You can do the self test by holding the trip reset button while turning the key to on. The tach should go to 6,000 RPMs, then 4,000, then 2,000 and then to 0. After I ran this test several times the tach started working again. The more I read about the crankshaft position sensor, I don't see how that can be causing the problem. I would think the engine wouldn't run or wouldn't run correctly if that was the problem.