ebacherville

OK, I Got this 87 Pulsar today, I was told the spedo was over a 10-15mph ... So I got out the GPS and tested it.. My GPS is usually right on the money.

AT 50MPH on the speedo, in reality I'm moving at 40 mph on the GPS

To go 60MPH on the GPS, I have to have the speedo at 80 mph

AT 60mph real world (on the gps) my revs are at 3500 rpm
I have the 1.6 liter throttle body injection, and automatic tranmission

So can any one tell me if the revs are right for 60 mph?


And can any one tell me more about the speedo setup in my pulsar.. I'm assuming its mechanical.. so why would it read so fricken high.. I've seen them off a bit, but 20mph is way off.

I will also Add , My tires are 185/70 -13's there almost new.. so that should not be the issue.

Thanks,
Jason

bob89sentra

First off the stock tire size for your car is 155/75 R13 if you upgrade to a wider tire you also have to have a lower profile like 175/70 R13 or 185/65 R13 to keep the same diameter tire.

Now if you are running 185/70 R13's it would have the opposite problem from what you describe, the speedo would read lower that your actual speed. What it looks like happened here is the speedometer spring (clock spring) has gotten weak, and the faster you go the further off it is saying you are going than you actually are. The easiest thing you can do is go to a wreacker and find another one and replace the whole dash. You also might be able to find a new one at a dealership, but you would have to be willing to fork out several hunderd dollars.

I have also heard of people taking apart their speedometer assembly's (not recomended) and moving the needle a little untill it reads accuratly at the desired speed. They said it will be off at other speeds, but at the haghway cruising speed it will be pretty close for a while, but over time the clock spring will get weaker and start to be off again.

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89 Sentra owner 9 years 205,000 miles and counting!

ebacherville

Thanks for the inforon the tires.. any wayi was thinking the same thing.. week spring makes sence... So My revs are right on for my speed.. or close.. just want to make sure on that..

I may just say screw it and drive it way off.. as I really done want to swap a 58,000 mile odomometer for a 100,000+ mile odometer.. if I ever want to sell it that make make a big diffrence.. Maybe if I documented the swap on video or somthing that would surfice as proof?

I have heard horor stories about people that do swaps and get nailed or tampering with the miles on a vehicalafter they sell it.. Dont want that..

Jason