This issue is driving me crazy. I'm not new to working on cars and if I had a specialty, japanese cars would be it. However I'm stumped here.

So my wife's parents gave us this really nice old 92 Camry Wagon. It's in great shape. 148k miles, 4cyl, blue/silver color and the body and interior is in great shape .the problem I'm having is with the Speedometer. The tach, gas, temp, trip and odometer are reading correctly. The speedometer is reading like 13 below what I'm traveling. Here's what I've done so far.

Replaced the VSS on the top side of the trans
replaced the whole gauge cluster from one out of a 1992. (Read about the capacitor issue, not experienced in that so I just swapped the whole thing .what would the chances of both being bad?)

Both of these solutions failed to fix the problem. But here are some things to note. It's being a lil sluggish taking off. Once it gets speed it's fine. I'm gonna check the plugs to see if it just needs a tune up..God knows when the last time they did that. Trans shifts fine and perfect in all gears and O/D works fine as well.

But im thinking this could be the problem here. Since this is my first Toyota I'm not sure but maybe somebody could chime in. Sometime before my father in law got the car the previous owner put 16 inch wheels and tires on the car .the tires are kinda low profile. I think the wheels are some newer model Nissan wheels. Could this be the issue? I'm pretty sure this car came with 14s from the factory and I know these older cars may or may not have the built in compensators for different wheel sizes so the cars adjust so your speedo stays correct. I know that newer cars do. So since bigger tires and wheels take longer to make a full rotation vs a smaller tire could this be why my speedo is reading lower?

Sorry if this is long but I wanted to be thorough plus throw out some ideas. Any insight to this problem would be helpful. Im kind of at a standstill here in my mind as to what I could do. Thank you for your time in reading this and any help you can be.
​​​​​

 

Tire size might cause 4 mph.

Might be low voltage. Check for battery voltage at the speed sensor red/blue wire.

How is the tachometer operation as in accurate. The tech, dash icon light bulbs plus speedo receive power from the same 12V source.

 

I'll check that voltage and get back to you. The tach reads just fine from what I can see. The speedo doesn't move at all until I get up to about 12-15 mph. I thought for sure the VSS or whole gauge cluster would of done it. I have a brand new battery in the car also. I'm beginning to think the problem may be in the ECU or some wires messed up somewhere. The thing about the wires is that everything else works just fine. Thanks for the reply by the way. It's greatly appreciated.

 

See private message.

 

How do I view my private messages?

 

Log into the site.

On the top right corner will be blue area stating Welcome Pmb1903. Under the name will be "Private Messages". Click on this. Check incoming messages.