97 Ranger Manual Cold Idle Stalling

[97rangerdanger]

Hey, I am new here so sorry if this is the wrong section. I have a 97 ranger xlt manual. Picked it up from a friend who had it sitting around for a few years, it only has 77k miles. It has a manual transmission. Whenever I start it up it runs (badly) for a second or two then stalls unless I give it gas continuously. It hesitates to accelerate and runs rather very poorly putting along. The gas is also not sensitive and jerky. However, after driving around for ~10 minutes all of these problems disappear and it runs smoothly. It has the check engine light on. I have just replaced the spark plugs and the fuel pressure regulator. My guess is the MAF sensor? Any help would be greatly appreciated!

 

[tomw]

Does the engine idle fast when cold? If not, it may be the IAC, or it may be the coolant temp sensor. If the IAC - Idle Air Control - does not open up properly, you won't get a faster idle when the engine is cold. If the CTS - coolant temp sensor- mis-reports the actual temperature, the computer won't command the IAC to bump the idle, and it won't add extra fuel to make up for the lowered evaporation rate of a cold engine. You'll get stumble and poor idle or stalling. The IAC may be cleanable if gummy. The CTS would be measurable with a VOM to determine if it has proper resistance(changes with temperature change).
tom

 

[RonD]

Welcome to TRS

As tomw said the ECT(engine coolant temp) sensor is all the computer has to tell it if engine is cold and needs to be "choke".
All cold engines need a Richer fuel mix and higher idle to stay running, which is what choke plate did on a carb, fuel injection couldn't change that, but also couldn't use a Choke Plate, no Jets.
So ECT sensors were added when fuel injection and computers were added.

There are now TWO coolant temp devices, the ECT sender and ECT sensor
SENDER is for the dash board temp gauge only, same type of unit used for 60 years for driver's engine temp gauge.

SENSOR is different but looks similar, they are not interchangeable.
They are also not expensive, so in your case I would just replace it, although you can test it if you want, but testing is not always definitive for these.

ECT Sensor should have Grey/red and Green/red wires
Sender wires will be different color