91 escort 1.9 auto, torque converter appears to stay locked in. get the car to roll in reverse and shut engine off it will turn motor till stopped just like a manual transmission. will stop in gear but pulls motor down real hard. Idles at about 40 MPH

what is the car?
does it have a lock up torque converter for final gear
torque converter is stuck in final drive, lock up or direct drive
you can un plug direct drive to get it going

there is a thing called a torque converter between the engine and the transmission. You can sit with the transmission in drive with your foot on the brake and go no where. The reverse is also correct.
If the transmission has a major failure ( total lock up) then the engine will still turn because of the torque converter
In remote and very remote at that circumstances if the transmission locks up and jams the torque converter into one solid mass then it will lock the engine
Basically I suspect that you are being scammed for more money.

I assume you have an auto tranny and I would be dropping off the inspection plate under the torque converter and checking for a failed flexi plate that drives the converter

band or a servo piston is jammed, either way req an experienced auto mechanic.

Had similar trbl once, turned out t be worn distributor. Also, torque converter can cause it if not releasing lock up cond.

there are several relays for your fan, one the coolent senser , and relay for fan on side wall ,, also replace t-state, at least every other year I have a 94 and have same issue, these little gems seem to have a heat up problem

This sounds like a problem with the torque converter lockup system. Usually the torque converter lockup solenoid is at fault in your condition. This solenoid usually locks up the torque convertor (which acts like a clutch in an automatic transmission) when you are driving at a certain speed, and unlocks it when you press the brake, and/or come to a stop. When a torque converter stays locked up, and you stop the vehicle, it acts like a vehicle with a manual transmission, if you bring the vehicle to a complete stop without applying the clutch pedal, the brakes stall the engine. Basically, if the torque converter can't unlock, even when you come to a stop, the engine is still locked to the transmission, and even when you apply the brakes, the torque converter doesn't slip and freewheel like it should, but instead stalls the engine.

sound like modulator is dead. check on the side of
trans. for broken wire or vacuum hose undone

Check the fuse box is not full of water.
Thet suffered from leaking windscreens, and it filled the fuse box.
If not, you are looking at a faulty ignition switch.

TL

Hi Michelle;
I know this is frustrating but I do not want you to throw money at your truck when it is not necessary. The 91 is an OBD1 system. Have you downloaded the codes? I can be of more assistance if I have the codes to diagnois. You definetly have a problem, I wan to solve it.
Since you just had a new engine installed and then the problem started, I would look very closely at the fuel lines. Perhaps the engine torque is pinching a flex line. Perhaps when you engage reverse, something is hitting and grounding out. It seems to me when you engage reverse the torque rolls the engine to far and maybe grounds out the coil. Are your motor mounts in good shape? Check by opening the hood, put your foot on the brake hard, engage reverse, and keeping your foot hard on the brake, give it gas. If the engine rolls up off the mount the mount is broken. You may need to have someone help you with this.
Let's keep talking. I really want to help.
Thanks;
Rich
RPM Northwest