need help with questions on transmission q45

[ZHOTBOY]

Hey guys thanks for your help my cars transmission is going out i have a few questions though my transmission still works for right now but when i stop at a light it takes awhile to get upto speed but once im going im going! the next problem with my transmission is when im driving on the freeway and i let my foot off the gas my speedometer needle drops all the way down and my car starts to jerk like if my transmission wants to go to a lower gear but if i keep my foot on the gas its fine i need help please and does any one have a transmission for sale 1991 infiniti q45 auto tans thanks for your help

[elwesso]

Welcome!

First off, if you werent aware of this the 90-92 Q45s started in 2nd gear... Try shifting into 1st gear and see if that helps... Its possible you have bad injecotrs and knock sensors, that is only making it worse...

Im not sure about the other things, but i think the 2 other symptoms could be unrelated.. The speedo not working right could be the sensor or the speedo cluster... Does the odometer work good?

I ahve a transmission from a 94 Q that will work......

[Jesda]

How does it idle?

[squeefoo]

Is the ATF fluid/filter fresh? Do a search on adjusting and cleaning the EGR/IAC valve, sounds like the same prob others have had. Fuel filter?

[maxnix]

If your transmission is toast, get an OEM rebuilt one from Joe. Plenty of previous posts about this subject.

[tangalora]

It may be that the conjunction of speedometer & transmission issues are actually related. See this quote from Dennis (q45tech) in thread:http://www.nicoclub.com/zerothread?id=50463 (www.nicoclub.com/zerothread?id=50463)

[quote=Dennis]... the speed sensor on the transmission shaft creates a variable frequency which is converted [by an IC] to a zero to 5.0 volt signal which drives the speedometer display gauge [just a voltmeter]. The same zero to 5.0 volt signal is isolated and feeds 4 other systems [ABS, AT, ECU, PS, Cruise] so if these systems are working the meter is just bad [sticky-worn pivot bearings].

Seems to me, if you lost your 5 volt signal, for example, the speedometer would drop like a rock and the engine would sputter & gurgle. Just guessing (never take anything from me as gospel).

See also the perhaps related thread titled "93 Q45 transmission/speedometer weirdness" at:http://www.nicoclub.com/zerothread?id=49337 (www.nicoclub.com/zerothread?id=49337) where Wes kindly supplied a simplified transmission diagnosis algorithm.

Disclaimer: I don't know what I'm talking about (but I can read well if pointed in the right direction).