Taurus Car Club of America : Ford Taurus Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter #1
98 3.0 vulcan AX4N

I replaced the forward control valve and the 3-4 shift solenoid. The pump looked good and Ive done 2 flushes and added seafoam twice. What am I missing? I think it may be shifting into O/D because when im at highway speeds and let off of the throttle and pull the shifter down from O/D to D, it seems to downshift possibly. At 70 it should be going fast enough not to make a difference if I was only in 3rd gear already and didnt have O/D. Could it go into O/D and just not stay there, not lock in or something? Could that be a lock-up issue? I can feel the TC lock-up while its shifting thru the gears.
 

·
Premium Member
Joined
·
14,126 Posts
What's your rpms when at 60 mph? Same in 3rd and 4th?
 

·
Registered
Joined
·
17 Posts
Discussion Starter #3
@60 MPH with the shifter in O/D or D, the RPMs are 3K. If the shifter is in O/D and I let off of the throttle and im coasting @ 60 my RPMs are 2k. When I let off of the throttle the RPMs drop quickly to 2k, but then its a steady 2k like its engaged.
 

·
Premium Member
Joined
·
14,126 Posts
That sounds like it shifts to OD when you let up on the throttle?

If so it may be the TPS sensor. You can check this with the key on engine off and backprobing the TPS sensor. It should read just under 1V when the throttle is closed, definitely not over 1V. And smoothly progress up to about 4.5V at WOT. Any skipping or hanging up of the voltage means it is no good.
 

·
Registered
Joined
·
346 Posts
Don't mean to hijack the thread but what would it mean if my TPS is reading 4.16v throttle cosed - 0.46 WOT? car seems to run fair. Does this mean my TPS needs replacement?
 

·
Premium Member
Joined
·
8,433 Posts
Set the cruise @ 65 and tell us what the rpm's are.

Mike
:dunno:
 

·
Premium Member
Joined
·
14,126 Posts
QUOTE (outatyme @ Mar 12 2009, 09:39 PM) index.php?act=findpost&pid=708106
Don't mean to hijack the thread but what would it mean if my TPS is reading 4.16v throttle cosed - 0.46 WOT? car seems to run fair. Does this mean my TPS needs replacement?[/b]

The normal TPS voltage should read ~.85v-.99v at closed throttle and ~4.5V at WOT. There should be a smooth upward transition as you slowly open the throttle. Beware digital voltmeters that have auto ranging as there may be a perceived jump as you change decimal values on the read out, such as at <1v to > 1v.

You should also make sure the input voltage is close to 5V.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #12
It's been getting a p0761 the entire time. The retaining clip wasnt broken, but I replaced it and the valve anyway.
 

·
Premium Member
Joined
·
8,433 Posts
3200 @ 65 means it is definately not shifting. Is the flashing light still coming on

Mike
:dunno:
 

·
Registered
Joined
·
17 Posts
Discussion Starter #15
QUOTE (mwt @ Mar 15 2009, 07:18 PM) index.php?act=findpost&pid=708889
3200 @ 65 means it is definately not shifting. Is the flashing light still coming on

Mike
:dunno:[/b]

I dont have a flashing light. Just the check engine light. If im in O/D and moving at speed and let off of the throttle and coast, the RPMs drop to normal, maybe around 2k as long as I dont push the gas. If im coasting along and I pull the shifter down to D, the RPMs jump straght up. It seems like its in O/D but it wont stay there if any demand is put on it.
 

·
Premium Member
Joined
·
14,126 Posts
Speed sensor.

The shifting parameters are based on TPS reading and the vehicle speed.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #18
Is there anyway that the Speed Sensor could work fine except for when O/D is called for? Or up to a certain range? I have not had any problems with my speedometer.
 

·
Registered
Joined
·
17 Posts
Discussion Starter #19
QUOTE (fordfool @ Mar 18 2009, 07:25 PM) index.php?act=findpost&pid=710130
Is there anyway that the Speed Sensor could work fine except for when O/D is called for? Or up to a certain range? I have not had any problems with my speedometer.[/b]
My speedometer runs off of the vehicle speed sensor, so maybe I should be looking at the turbine speed sensor or the transmission speed sensor whichever it's called.
 

·
Premium Member
Joined
·
14,126 Posts
Maybe the problem is from the speed sensor to the PCM to the tranny then?
 
1 - 20 of 20 Posts
Top