I have a 94 Ranger with a 2.3L, 5 spd, 2wd. The problem has steadily gotten worse over a 3 wk period of time. Initially when I'd take my foot off the gas and depress the clutch, it sounded like I was dumping the clutch. So I started delaying when I engaged it. About a week ago I was in 4th gear and going at a steady clip, and when I let off the gas to sort of coast, the idle was going vvvggnn......vvvggnn........vvvggnn until I engaged the clutch again. Now it takes about 3-5 seconds from the time I let off the gas, until the throttle fully disengages/or the idle returns to normal. Idk which it would be. I thought it might be theTPS and/or throttle body, but I had it put on a reliable obd machine and got the 118 code but nothing indicating either the TPS or throttle body was having issues. Any suggestions? Any information will be greatly appreciated!

 

Welcome to the forum

3 digit code list here: https://www.therangerstation.com/tec...gitcodes.shtml

118 ECT sensor is/was high or open

You need to check the wires on ECT sensor, if they look OK replace ECT sensor its not expensive, and yes this sensor can effect idle
This has no connection to dash board temp gauge, just FYI, that uses a Sender, 1 wire, not a sensor, 2 wires

ECT(engine coolant temp) sensor tells the computer when to apply Choke to the cold engine
When you start a cold fuel injected engine it still needs to be choke to run well, so ECT sensor was added
At cold start, not touching the gas pedal, your engine should start and REV to 1,500+ RPM
Then RPMs should drop to 1,100 or so, high idle
Then as engine warms up idle will drop on its own to about 750 after full warm up, on a 4cyl engine

Computer sets idle RPMs using the IAC(idle air control) Valve located on the upper intake near the throttle plate
IAC Valves can be cleaned

MAF sensor can cause issues as well and can also be cleaned, easy to do

TPS(throttle position sensor), this is used to give the computer the "heads up" that driver wants to accelerate or coast, the MAF sensor and RPM sensor have a delay, so engine would stumble a bit with the sudden rush of air when throttle plate was opened, carbs used an "accelerator pump" to add extra fuel when throttle was opened, the TPS does the same job, solves the hesitation issue
When speed is higher and throttle is closed(TPS under 1 volt), coasting, then computer will shut off the fuel injectors to save on gasoline and will turn them back on when RPMs are under 1,500 or so
So just FYI, when going downhill stay in gear and coast, clutch pedal up, to save on fuel, opposite of what you would do in a carb engine

TPS can cause the problem you describe but...............you should feel an issue when accelerating also, not just when in "Neutral"(clutch pedal down)

 

You are going to be my hero if one or some of these things turn out to be the problem, and I'm able to fix it sooner rather than later! It usually takes me about a month to diagnose an issue, research it, buy parts and replace them. Thank you ! ! 😊