transmission REVOLUTION SENSOR ISSUE! NEWBIE

[BAJACALIZ]

Hi guys iam having some transmicion problems (copy paste--->) NOW THE PROBLEM, EXPERTS PITCH IN, WHEN I BOUGHT THE CAR THE OWNER SAYD THAT THE transmission WAS TAKING A COUPLE OF SECONDS TO ENGAGE TO DRIVE, AFTER A COUPLE OF TIMES 3 DAYS AGO IT STARTED TO TAKE LONGER TILL D WOULD NOT ENGAGE, 321 WOULD WORK BUT IT WOULD SLIP BADLY, NOW WHAT IS WEIRD THAT AFTER I PARKED THE CAR FOR THE DAY IT WOULD WORK JUST FINE WHEN COLD, AND THEN IT WOULD START AGAIN WHEN I WOULD DRIVE IT WARM, NOW I DONT THINK ITS AN INTERNAL MECHANICAL PROBLEM, BECAUSE IT WORKS FINE WHEN COLD IT TAKES ABOUT 4-5 SECONDS TO ENGAGE TO D, I CHANGED THE transmission OIL TODAY AND NOTHING CHANGED, I DISCONECTED THE TCU AND GOT IT INTO SAFE MODE, IF IN SAFE MODE DRIVE WOULD ENGAGE RIGHT AWAY IN DRIVE BUT LOCKED IN 3RD (321 ALSO IN 3) WITH NO DELAY.... WHAT COULD BE THE CAUSES OF THIS? I WAS GOING TO DROP THE transmission BUT I WANT TO DO SOME REASERCHING WITH THE EXPERTS.COULD IT BE INTERNAL DAMAGE? OR A TCU OR TPS PROBLEMS,

i think it might be a revolution sensor, could it cause the slipping somehow? i also disconected and conected the gray plug on the tps sensor and get kinda of a buzzing sound coming from the back of the engine or top of the transmission.

car: 91 Infiniti q45 164,xxx miles, transmission may be replaced unit due to a drain plug, no sliping isues when i bough it like a week ago but was taking a couple to engage in D
Modified by BAJACALIZ at 3:16 PM 6/28/2008

[Q451990]

A bad revolution sensor should show up in the self test... you can download the factory service manual at http://www.phatg20.net

The earliest manual available is for the 1994 model, but the self test steps should be the same. Have you tried a pan drop and filter replacement yet?

Heath

[BAJACALIZ]

yes i did the pan drop and filter change, i used the fsm to do the self test but cant get it to give the codes, it just says AT CHECK while i press and release the gas pedal like the fsm shows, could it be a bad tcu? i will be using the fsm and a couple of head pain pills to do de diagnostic of each sensor i can with a voltmeter that o have

[Q451990]

Make sure you're testing while the transmission/engine is hot, just after turning it off from normal operating temperature. It won't work on a cold transmisison...

Heath