How is a tune up going change the relationship between road speed and motor RPM?
I always thought you had to change gear ratios to do that.

 

I think he meant "tuned" as in using a tuner, not tune-up as in new plugs and whatnot. Maybe he adjusted the speedo for oversized tires or something.

 

Yeah my truck runs at 3000 RPMs at 70, my ovedrive isnt working definitely because when I hit the button, it moves up like 250 rpms, then moves back to the same rpm like a second later. If anyone knows how to troubleshoot this, it would help out. I bought the truck light this, and has ran like this since I have had it.

Here is the picture of the rpms im running, and the other picture is of my fuse/relays. Should I have a relay on relay 3, where the abs relay is?

 

Getting any trans codes?

 

Back a long time ago, I did have the 3-4 gear code, when I bought a programmer than could read them, but I took it to the guy I bought it from, and he said there was nothing wrong with it.. I still thought there was, just because I have never heard of a engine running that high at 70. How can you reset the computer for the codes to pop back up? Or should I take it to autozone and have them read the codes for free to me..

 

The guy your bought it from is blowing sunshine up your skirt. I run about 2200 RPM or so at 70 in O/D.

If you can read codes, your programmer should be able to erase them as well.... I would bet you are getting a code for the No 3-4 upshift. Or some such. Trick is, is it the solenoid that is the problem, or something else...... Have you been into the pan lately? If there is no warranty or such on the trans, I think first step would be verify that the PCM is actually attempting to ground the O/D circuit..... (hard to test that on a moving vehicle.... gotta get creative, or have a scanner that will tell you.)

 

When i hit the overdrive button in the cab, and it jumps up rpms, wouldnt that mean the overdrive solenoid would be working (or at least have a negative and postive charge)? Therefore nothing should be wrong with the switch, or overdrive, it could be the tps or whatever the other sensor is maybe?

 

The 200 or so RPM jump you get is more than likely just from TCC unlocking. (but, it should drop back down after a little bit..... )

What size tires, and what gears do you have? 3K is WAY to high at 70 for O/D to be working the way it should, unless you have DEEP gears, or tiny tires.