everytime it gets below 30 degrees or so it won't start, it will turn and turn and turn but never fires, i've tried changing the plugs, the wires, i've tried jumping the battery when it gets cold, i've done everything i can think of, but it seems when snow hits the ground it just won't start. does anyone have any ideas why this would happen? or had this vechile where this happened too?

Here is a little review of how you engine is controlled. Your truck has a computer (ECU) that with input from different sensors determines when spark plugs fire, fuel is injected, how much fuel is injected, etc. your truck has :

MAP ( Manifold Air Pressure): outputs a square wave signal to the computer, ranging form 90-170Hz (160Hz is atmospheric pressure - no air is needed by engine) idle is approximately 120hz, and deceleration is 90Hz. Therefore, as the engine accelerates, the frequency increases, the computer ?sees? that it needs more fuel.

BPS (Barometric Pressure Sensor): Barometric sensor measures the pressure of outside air - more altitude = less oxygen in the air. The computer ?modifies? itself to compensate for this.

Engine coolant sensor: Senses the temperature of the engine - as the engine warms up, it can use a leaner mixture, and therefore less gas.

Air charge Sensor: Similar to ECT, measures how dense the incoming air is, knowing that more fuel is needed for colder air

PIP sensor and knock sensor aren?t extremely vital to this discussion, so I will bypass those

TPS (throttle position sensor): Used to determine the position of throttle (open, closed, partial opening) As you get closer to WOT, the computer relies less and less on the exhaust sensor readings, and more and more on the built in tables.

When the computer loses one or more inputs it will go to a default setting. ( I bet it not for 30 degrees) If this happens the check engine light will come on. But if the sensor is faulty and sending bad Information but is still understood by the computer then engine runs poorly and is hard to start. any of the above sensors can be causing the problem. Are there other things, Yep, but start here first.

P.S. there is no cold start valve on your engine, good answer for some cars but not your ranger.

sounds to me like fuel line freeze. add a bottle of water remover to your tank and never let it get under 1/2 full in the winter months.

if your engine is fuel injected, then have the cold start-idle enrichment vale checked out. this is about the only thing that causes hard starting in cold weather

when the vehicle stands in the cold for ay length of time things do happen your problem may be the cold start sensor or even temp freezing of the fuel pump. the engine conrtol computer should be storing a code when the engine fails to start.
you may want to get you local dealer to do a diagnostic check, before changing sensors and things as this may just be a waste of your
valuablele time and money.
good luck

Seeing as how your truck is from 1990, here's some news that may be disheartening. Your truck has what's commonly called an OBD I (On-Board Diagnostics) computer. The problem is, because everything went to OBD II computer systems in 1994 (or thereabouts, I'm not sure) most dealers/parts places don't use the OBD I diagnostic tools anymore.

However, there is a light in this conundrum. What you need to do is to get the check engine light to flash (a Haynes or Chilton's guide can tell you how to do this), and when it does, it will tell you by flashing all of the trouble codes that are stored in your computer. Now, a little detective work: As soon as you get all the codes from your system (and keep in mind, some codes only come on when the computer is under the KOEO condition (Key On, Engine Off). Once you have your codes, consult a manual that can tell you what the code means. If you have a Haynes or Chilton's manual, it should list what the code is and what it means. Then, you have to work backwards from there to fix the problem. However, if you have no malfunctioning sensors, what you can also do is disconnect the negative battery cable for 30 seconds. Doing this will reset the computer to factory specs, which should allow you to start your truck, if there also isn't anything wrong, like a frozen fuel pump.

__________________
Billie, my "sparkly" blue 1992 Ranger

2.3 L I4
4 speed manual w/OD
Almost 180K miles, still going strong

Trying to dispel the myth of F.O.R.D. ...

Isaiah, please notice the OP's original date of the first post. 27 MONTHS AGO!
also, notice that it is an "guest" which means they are not even a member here.
why would you comment on a thread from 27 months ago?

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Sorry, the thread somehow got bumped up...didn't know about the date it was started; I apologize.

__________________
Billie, my "sparkly" blue 1992 Ranger

2.3 L I4
4 speed manual w/OD
Almost 180K miles, still going strong

Trying to dispel the myth of F.O.R.D. ...

Hello,

new to the forum but I need a lot of help. Hoping someone can