Resolved AOD Early Shift at low RPM Stock 91 5.0

[Yyhoop]

At takeoff unless I put my foot in it I'm in 3rd gear before I hit 30MPH and is bogging down, no hesitation though. This car has been sitting for the last 12ish years. Major issues have been dealt with and the car generally runs great. Car idles fine.
At WOT shifts fine and timely with power with no issues in the higher RPMs.

I checked the voltage on the TPS and no matter how I adjust it won't go below 1.35V without some modifications to allow more adjustment.

I didn't open the throttle to check the upper range. I drilled out the hole to see if I could get some additional adjustment and got down to 1.22-23. Is this an indication of a bad TPS? Timing was checked and set at 10. IAC was disconnected to set the base RPM.

If it's a bad TPS can this cause the early shift and bogging....when not at or near WOT.

If not any suggestions? Drivetrain Issue, TV Pressure, loose cable?

 

[AeroCoupe]

Slot the holes in the TPS and get it between 0.6 and 1.0 volts with the TB closed. I like to set them at 0.85 or so. Not hard to do and have done it several times.

Before you do anything check the sweep on it and make sure there are no dead spots and with the TB at WOT you should have a minimum of 4.35 volts and no more than 5.0 volts as that is the maximum vref.

Good write up by jrichker here (post #2)

Tps Voltage Question

Hi all, just picked up a 86 LX, and think I've run into a idling issue. The motor is a 306 EFI, GT40 Crate motor 42lb injectors Bama 4 Bank Chip 70MM TB 76MM Turbo/w 10lbs boost B303 Cam GT40X Heads The car has a hard time idling for the first 30 seconds or so. I've got play with the gas pedal...

stangnet.com

 

[90sickfox]

Your kick down cable at the throttle body is not connected or not adjusted properly. Driving the car like that can damage the transmission internals.

 

[Yyhoop]

Your kick down cable at the throttle body is not connected or not adjusted properly. Driving the car like that can damage the transmission internals.

I adjusted that this morning, that's exactly what it was, it's kicking down into 1st now as it should. I can get a little more aggressive with it to get it to shift in the higher RPMs but it was way too loose. The TSP was also high, slotted it out some more and the voltage is down where it should be with no dead spots and idles flawlessly under load. The car has only been driven on test rides, but I think its ready for a little longer test now.

While I got ya...Will air in the coolant system cause the temp gauge to read on the high side of the normal range?

 

[Yyhoop]

Slot the holes in the TPS and get it between 0.6 and 1.0 volts with the TB closed. I like to set them at 0.85 or so. Not hard to do and have done it several times.

Before you do anything check the sweep on it and make sure there are no dead spots and with the TB at WOT you should have a minimum of 4.35 volts and no more than 5.0 volts as that is the maximum vref.

Good write up by jrichker here (post #2)

Tps Voltage Question

Hi all, just picked up a 86 LX, and think I've run into a idling issue. The motor is a 306 EFI, GT40 Crate motor 42lb injectors Bama 4 Bank Chip 70MM TB 76MM Turbo/w 10lbs boost B303 Cam GT40X Heads The car has a hard time idling for the first 30 seconds or so. I've got play with the gas pedal...

stangnet.com

Making the holes even bigger worked...no dead spots along the sweep but I did see 5.79v on the high end

 

[AeroCoupe]

I do not know what the maximum voltage is on the VREF other than it’s 0-5 volts. That may be based on 12 volts and with an alternator charging at 14+ volts it could very well increase the 5 volt.

 

[90sickfox]

An air pocket in the coolant can cause higher temp readings. Most folks here get the front end as high as you can and top the coolant off. I use a vacuum fill ti fill mine. Either way will usually work.