Starts but no idle help

[jonwalden68]

I have a 97 ford ranger 2.3 5 spd I just bought today as a gas saver. It runs good when warmed up and will idle fine then but when you first start it when cold it's will not idle it's starts up great then goes dead my check engine light isn't working so I do not know if it has any codes any help be great

 

[jonwalden68]

Here's video how it does

http://s1283.photobucket.com/user/Jonwalden/media/Mobile%20Uploads/trim93A9EE1D-4A85-404D-9778-DE2820280452_zps388fef6a.mp4.html

 

[Captain Ledd]

My '97 2.3l did the same thing, but only after it sat for a looong time. Eventually I drove it more and it went away, and has been away for a good 2 years.

But I had to rev mine for a few minutes one winter.

Maybe driving it around for a week might help flush out anything old. I wish I could help more but mine did exactly as yours did, and It went away after I drove it around more.

 

[jonwalden68]

I looked the motor over and can't seem to find anything wrong except temp sending unit isn't working for the coolant

 

[jonwalden68]

Mine does it after sitting just a few hours max

 

[tmcalavy]

Without the temp sensor, the computer doesn't know the motor is cold so it doesn't adjust the idle for engine warm up...it's supposed to start, idle up to about 1200 rpm and then gradually drop the rpms to about 500-750 as the engine warms up. The temp sensor and IAC provide the data the comp needs for cold start and warm up routine.

 

[adsm08]

The IAC provides no information. It's just a solenoid and a plunger.

Try cycling the key on and off a few times before starting, see if the issue persists. It sounds like fuel pressure bleed off to me.

Coolant temp sensor still needs to be fixed though. Always start with the problems you know exist before looking for other ones.

 

[jonwalden68]

I tried cycling the key the several times and issue still there

 

[RonD]

Fuel injected engines have no "choke plate", there are no Jets to pull extra fuel from when engine is cold.

So the computer mimics the "choke plate" on cold starts.
There are TWO coolant temp readers on all fuel injected engine.
A 1 wire SENDER for the dash board gauge
A 2 wire SENSOR for the computer to use

On start up the computer looks at the coolant temp(2 wire sensor), if cold the computer runs engine rich, with higher idle(approx. 1,000), and advances the spark timing.

As engine warms up the computer will slowly lower the idle and lean out the air/fuel mix.
Once engine is warmed up the computer use the O2 sensors to set air/fuel mix.

Yes, IAC valve is used by the computer to control the idle, it is not a sensor, it is a control device.

Computer's coolant temp sensor(ECT sensor) on the 2.3l is located under the intake manifold, front part of the block, 2 wires.


CEL(check engine light) not working is a bad sign, either seller disconnected it or computer has a major problem, neither is a good sign

 

[jonwalden68]

Bulb is burned out I pulled the codes and 2 were for the o2 sensors both of them and 1 code for high voltage to egr valve. I'm going to replace the coolant sensor which one is it I need then temp sensor or sending unit

 

[txgocartB3000]

RonD - good info there, you should have like a gazillion Rep power points with all the help you give.

jon - the 2 wire one

Ray

 

[jonwalden68]

So the 2 wire one would be the sending unit then?

 

[Andy D]

Yah, that is the one the cold start needs to see. The one wire is just for the gauge.

 

[jonwalden68]

Could the o2 sensors cause it too not idol when it's cold? It says both o2 sensor heating element or something like that

 

[jonwalden68]

??