transmission Bad on J30?

[alex61089]

Hey guys i posted some stuff about my RPMS and ect. But i just realized something.. Starting last night ( but i didnt think nothing of it ) When i first turned my car on after it's been off for a while. The AT light comes on for about 2 seconds then starts blinking. ( it doesnt do this everytime i guess you could say when the engine is cold?) Then the light goes off. When im going high speeds my car jumps RPMS If i let go of the gas at say 70mph it drops down to 2,000 rpms then jumps up to 4,000; Makes no sense. I know.

So is this something to do with the transmission? or could it be the MAF? because I cleaned the MAF and it seemed to be fine for about 2 days then it went back to normal. I'm confused about this so help from you guys would be greatly appreciated Just to ween out things so people can narrow it down, heres everything i have done to this car in the past month since i owned it.

Replaced : TPS, Fuel Filter, Fuel Pump, Gas Cap, Air Filter, Air conditioner Pulley belt, Flasher control unit, OEM NGK Spark Plugs and I think thats it so far.

I also cleaned the MAF and YES the TPS is at the correct voltage.

sigh. lol..

[driverdriver]

If your RPM's rise and your transmission shifts roughly or doesn't shift at all, then its a transmission issue which indicates you need a new rev sensor. If your RPM's are shooting up and your transmission is shifting fine, it's something else.

[alex61089]

yeah it doesnt feel like the tranmission because it does shift fine, I think it's something else but i just cant nail what it is. I bought the Code reader from Emance on ebay (55.00) so im gonna connect that and see what codes come up.

[NJ93J30]

I know Im late on this thread but I have the same issue on my J30...did you get it fixed? what was the problem...I need to fix also..thnx

[yodawill2000]

There is a sticky on this forum showing how to run transmission diagnostic.No reader need.

Here it is.

Transmission Self DiagnosticsCourtsey of Gerardjg

Transmission Self Diagnosticsusing AT light below your temperature gauge on the dash1-Warm up engine2- Shut off car and turn ignition switch to ACC position3-Wait 5 seconds4-Move shifter to D5-Turn ignition switch on do not start

AT check light should come on for about 2 seconds

6-Move shifter to 37- step on gas fully and release8-Move shifter to 29-Move shifter to 110-step on gas fully and release

The At Check light should start flashing 11 flashes aslight pause and start over again. All flashes shouldbe the same length, any flash that is longer indicates atrouble the following list is what the trouble circuit or part is.

A longer flash indicates

1st Flash Revolution sensor2nd flash Speed sensor3rd flash Throttle position sensor4th Shift solenoid valve a5th Shift solenoid valve b6th overrun clutch solenoid7th tourqe converter clutch solenoid8th fluid temp sensor9th engine speed signal10th turbine revolution sensor11th pressure solenoid valve

[alex61089]

Right and if your diagnostic doesnt work then it means your neutral safety switch is bad or otherwise known as an inhibitor switch

[sconus]

Hey guys I just ran this diagnostic on my 94 j30 and instead of 11 flashes, i get 12. i get 11 even flashes then a pause then a long one, followed by 11 even and one long one. The pattern repeats. Has anybody else experienced this?
I wanted to check this out because my trans seems to stay in 1st way too lng then around 5krpm, jumps to 2nd then third really quickly. Most of my cars have been manual so tis doesnt seem normal to me.

[fourdrinie]

try adjusting throttle positioning sensor....

[sconus]

thanks for the quick reply! this sounds exactly what could be the issue here! I just read this threat that talks a bit about it
throttle-position-sensor-check-engine-l ... 60188.html

The voltage reading to ground should be 0.40 to 0.45 VDC, measured with the engine running at idle. Higher readings will increase the idle speed and delay the shift points. Lower readings will lower the idle speed to a point and will also make the transmission over-sensitive to foot pressure on the pedal to the point of causing hunting and higher engine rpms at crusing speeds.

If you make changes in the voltage you must immediately afterward momentarily disconnect the grey connector with the engine running in order to clear the old and register the new "Throttle Closed" voltage in the ECM."

How do I make changes to the voltage? It didn't really say, or should i just buy a new TPS?

[GerryO]

The TPS output voltage will require adjustment after installing a new one. On a '93 there are two small screws that attach the TPS to the plenum. Loosen them and the TPS should turn a bit to either side, causing the output voltage to change. Again, on a '93, a strand of copper wire can be inserted into the backside of the TPS connector for the purpose of measuring output voltage. I believe the procedure is described in the FSM.

[sconus]

Thanks GerryO, now it's time to pick up a voltage meter. I hope this does the trick.