I have the same problem as stated here and don't

Better check tranny asap. look for burned smell in tranny fluid.should be a light red. dark or almost brown indicates breakdown of fluid and a failing tranny.

88 ford ranger 2.9 surges buck down when take off in first gear

possibly belt or bearing on alternator water pump ac etc.

Hi there hope i can help
there are about 5 possible sources of this problem

• intermediate band out of adjustment: you can do this at home touque it down to 35-45 ft-lbs then back it out 2 whole turns and that will adjust it
• Improper band or clutch application, or oil pressure control system: perform control pressure test.
• Intermediate servo leaking: Preform air pressure test of the intermediate servo for leakage service as required
• Overdrive clutch, O/D one-way clutch damaged. replace as required. (rebuild)
• Glazed Band: Service or replace (rebuid)

If this helps please give feed back
good luck hope all works out

Possible solution is to check the fan speed switch. These go bad and won't change the speed/ or function in the lower speeds.

Just a thought, You should start with a good tune up and don't forget the fuel filter. If after that I would check the flow of the catalytic converter. Just thinking of the basics first. Good luck and have a great day.

P1507 is "Idle Air Control System Underspeed Error". This code indicates a problem with the Idle Air Control (IAC) valve assembly, harness wiring for the IAC or the Powertrain Control Module. So checking the IAC next is the most logical step.

The ecm will tell the iac to idle up when it senses the ac is turned on.If the ac compressor doesn`t come on,there is no resistance on the motor,but the motor does not know that,so it idles up.Find out why the ac is doing this,it wouldn`t be low on freon,it would have to be,most likely the ac clutc going bad.Try this,turn ac on and when ac clutch goes off,be ready,and don`t get hurt,tap it lightly with a tool or something,but be carefull!.If it clicks back on,try it again when it stops,to make sure.This will tell you the ac clutch/coil assembley is bad.

could be either EGR valve stuck open or the IAC(idle air control)