My 1993 Q45 starts off on 2nd Gear

[Infinitiguy19]

Strange thing is that I have a 1993 Q45 made in 11/92 and it starts off on 2nd gear for some reason so could this mean that it also has Sodium filled exhaust valves?

[maxnix]

It probably means you have an older TCU. What's it's number?

[Haitian_King]

Strange thing is that I have a 1993 Q45 made in 11/92 and it starts off on 2nd gear for some reason so could this mean that it also has Sodium filled exhaust valves?

What is the obsession with sodium?

That's weird that your 93 starts in 2nd. Pull your TCU and look at the P/N. If the second set of numbers says 64U20, then you've got the 1st gear start. If it doesn't, well, that's a problem that'll need fixing.

Now, if you have the 1st gear start TCU in and it still starts in 2nd, then I'm stumped. I don't know of any reason why it would start in 2nd with a 1st gear start in. I'd like to say "Fail-Safe Mode" off the top of my head, but I don't want to alarm you. Run the A/T diagnostic and see if the AT electricals check out.

Has it always been like that? Or is this a recent development?


Modified by Haitian_King at 10:01 PM 4/15/2008

[maxnix]

Well it start in 1st if you manually select it or at WOT from rest?

[qship96]

Strange thing is that I have a 1993 Q45 made in 11/92 and it starts off on 2nd gear for some reason so could this mean that it also has Sodium filled exhaust valves?

Just one of the risks involved in purchasing a used old car with multiple owners...who knows what parts a previous owner changed, why, and how smart they were?

[DrewQ45]

Strange thing is that I have a 1993 Q45 made in 11/92 and it starts off on 2nd gear for some reason so could this mean that it also has Sodium filled exhaust valves?

I believe the earlier 93' had the same TCU as the 90-92. The change to first gear start took place later on in the model year. Reason why we always have to check model number when buying TCU.

[Infinitiguy19]

I see but when i remove the kick panel to get to the TCU will i have to take out the TCU or can i leave it in to find out the part number?

And I like sodium filled exhaust valves cause my 1991 had them and that car was one hell of a car?

[goody90q45]

The P/N should be on the face of the TCU and you will be able to read it by just removing the kick panel. If not, you won't have to remove the connector to get the TCU out and there's only a couple of screws holding it in place.

[lino]

It should look like this:

http://img405.imageshack.us/im...3.jpg

[StarPD]

Sodium filled valves run cooler. They resist burning and warping under severe use better than non-sodium filled ones. They are frequently used on high output competition engines and some severe service industrial ones. They ARE a plus, but for general use, aren't really necessary unless the car runs additional ignition timing and the owner redlines frequently or pulls steep grades with a heavy load.

[Infinitiguy19]

Do the transmissions go faster on car that star off on second gear or not?

I will try an pull off the panel tomorrow but I'm 99.9% sure its a second gear start.

Also you know when you floor the accelerator makes a clicking noise i mean really floor it " and no there is nothing wrong with my accelerator that I know of" but is that clicking noise supposed to tell the TCU that it should start off on 1st not second gear? If so then mine doesn't work lol.

[Q45tech]

If you would read and study your FSM you would see multiple [dozens]graphs and charts which show the relationship between TPS voltage and downshift speed [mph] for each gear and shift level position.

The kickdown switch is mounted on the throttle body as part of TPS, you cannot hear it open or close.

[Infinitiguy19]

The clicking noise I was referring to is the kick down switch.

I do have a first gear start TCU and I believe the problem was with the throttle position sensor AKA TPS being mis-adjusted.

[Haitian_King]

The clicking noise I was referring to is the kick down switch.

I do have a first gear start TCU and I believe the problem was with the throttle position sensor AKA TPS being mis-adjusted.

How did you re-adjust it?

[Infinitiguy19]

With my Laptop Consult, I want to try it against a real Nissan Consult though.

[Haitian_King]

With my Laptop Consult, I want to try it against a real Nissan Consult though.

Damn. I thought it was something I could just do on my own. I still don't have the laptop consult. Most I've got is the plug that a shop tech left in my car.

[Q451990]

You should be able to set it by reading the voltage at the ECU with a good volt meter. Just make sure the car is fully warmed up when you do it.

Heath

[Infinitiguy19]

True but you know how long the probe wires need to be. Much easier reading the voltage at the Throttle Postion Sensor its self with a Volt OHM Meter.

[Haitian_King]

I bought an Ohm meter from Radio Shack to ohm my injectors, but I never got around to opening the package. It's still in my trunk in the bag.

Can I find this procedure in the FSM?

[Infinitiguy19]

Adjustment:

Wiring Diagram:

Source: http://www.nicoclub.com/articles.php?id ... ub.com/FSM for more information

Some say to set it at the ECU harness but that would take for ever unless you have long probes, I like the Nissan Consult or equivilent or measuring voltage right at the sensor if posible.

Why do you want to adjust it though?

[Haitian_King]

Because I think that this is what will fix my intermittent problem where it feels like the car is starting in 2nd, or at least going through 1st really quickly.

[Infinitiguy19]

My Q45 has a OEM (64U20) Transmission Control Unit. The lack of power that made me think my car started off in second gear.