I have an 87 Ford Bronco II. It starts up very fast as soon as the key is turned and then quits running. I have to restart it and keep giving it gas just like an engine without a choke ( mine is a 2.9 liter fuel injected model). After the engine temp comes up a bit it will idle on it’s own. When I drive it anything over 45 mph and it has bad hesitation and will hardly get up to 50. I have replaced every sensor on the engine and no help. I don’t have a check engine light on the car. Ford did not install one. Can it be a fuel problem?
Likewise my 87 Ranger 2.9 is also not equipped with a CEL. Therefore step one is to hook up a scanner & check for trouble codes.
When mine was pinging & stalling off the line in 1st gear I pulled the codes & replaced a defective throttle position sensor.
When it was back firing something awful, I pulled the codes & replaced a defective ignition module.
When the cruise control was dead, I pulled the codes & replaced a defective vehicle speed sensor.
If you’re lucky the computer can tell you what the problem is.
You need to check for trouble codes, if you get an 11 “system pass”:
Check fuel pressure, if it’s good:
Put a vacuum gauge on it & check for a clogged exhaust.
BTW, not idling could be caused by a dirty/defective idle air control valve, but that would not cause your top speed of 45 MPH. If you floor it will it run good above 45?
Did you change the Coolant Temperature Sensor? Make sure you didn’t just replace the temperature gauge sensor. The two will be close together. Also make sure that the wire from the CTS has continuity to the ECM and is not shorted to ground.
Just some ideas.