This is a repost from the Drivetrain forum, where there's not so much activity as in here, so hopefully this is ok.

I finally got a chance to log some data today on my 93 and here's a weird thing I found.

Went full throttle at 52 MPH, 1600 RPM. (note, reported gear is "D4" before going WOT... The tranny was in OD) at 3250/54, the shown gear becomes D3 then at 4075/55 it becomes D2.
Now, at 5450 RPM/71 MPH it switches gear, then the RPM go down to 3675/76 and the shown gear becomes D3, then the rpms continue to go down a little and immediately the gear shows as D4 at 3525/77 and this continues to 3175/107 where I let go. Then I start cruising around at low speed/rpms and the reported gear always is D4 even at ~875 RPM/18 MPH. At 800/14, it finally switches to D3 for an instant then immediately to D2 at 800/12. (this within less than a second)

If I switch it to DRIVE, same thing happens.
So do I have a dead 3rd or the gear isn't reported correctly? (I did some work on the A4 connector but I'm pretty sure I connected everything right)
Thanks!

 

I was told not to floor it in 4th gear with the non-electric 700R4 because it wears out your overdrive sprag alot faster.

I blew mine a while ago.

 

Right, but what do I do then? If it's in Drive, it defaults to 4th too. At least per Datamaster.

 

I don't think the datamaster would know what gear its in because its a non-electric tranny.

It doesn't show on my Auto X-ray unless my converter locks up.

Ignoring what the datamaster says, how does your car drive and accelerate?

 

Well, I cut the 700R4 connector and there are 5 wires. One is ground, one is the TCC lockup and the other 3 report current gear. (2, 3, 4)
So the ECM definetely knows which gear it is in. (this is because there are separate lockup and release tables for low and high gears)

As for how the car feels... I don't know... I *think* it should be faster from about 60-70 to 100+.... then again I still need to replace the injectors. (the ones on the 94 engine I swapped in were all locked so I am temporarily reusing the 129K mile 93 injectors)

 

93s are 22# ones and 94s are 24#.

I dunno what to tell you though.

Thats odd.

Put it in 3rd and then race. It makes a difference on 700R4s.

 

Yes, I know about the injectors size, but even though the engine is a 94, the ECM is still 93, so it won't make a difference. When I switch to 24s, I'll reprogram it though.

 

When I raced in 4th I was 3-4 tenths slower over racing in 3rd.

This is only with 700R4s. It doesn't matter with 4L60Es.

I manually shift it now because I have to shift at 6700rpm and if I leave it in 3rd it shifts at 5700rpm.