4.0 Cold Crank??

[tobyduck]

98' ford ranger xlt, supercab, 4.0 V6, 2WD, Automatic

When cranking cold it will crank, sputters til it gets around 500 rpm. It acts like it is trying to idle up and if you give it gas it just sputters more and goes around 300 rpm. (I myself am amazed that it will run at that low rpm) This lasts around 15-20 seconds and then it will idle up to about 1000-1200 rpm. I cant fully drive it or give it gas for like a minute, after that its fine and runs great when it's warm...I don't have a clue what's wrong and there is no code. There is no problem with the MAF sensor or fuel pressure or fuel filter, fuel pump, spark plugs, coil pack, etc. I have been told that it is a water temp sensor problem but I don't know how to resolve it,

God Bless

 

[Nhaz]

IAC check it. Make sure its working. make sure its not clogged with carbon and that it moves freely.

This is effectively the automatic choke for the vehicle. Its located on the top drivers side of the intake manifold. 2 wire plug. 2, 10mm or 8mm bolts I cant remember which.

This is basically a solenoid when 12 volts are applied to the leads it will jump back and forth. If it doesn't, then its broke or clogged. Junk yards are full of them. Dont pay the stealership for this item.

 

[Big Jim M]

Yep!!

The iac reacts to the water temp sensor.. If the temp sensor is lieing to the iac it won't idle when cold! A new sensor is about $10. Put one on and see if that was the problem. THEN worry about the iac. If it idles good when warmed up it is highly likely your problem is the temp sensor.
Big JIm

98' ford ranger xlt, supercab, 4.0 V6, 2WD, Automatic

When cranking cold it will crank, sputters til it gets around 500 rpm. It acts like it is trying to idle up and if you give it gas it just sputters more and goes around 300 rpm. (I myself am amazed that it will run at that low rpm) This lasts around 15-20 seconds and then it will idle up to about 1000-1200 rpm. I cant fully drive it or give it gas for like a minute, after that its fine and runs great when it's warm...I don't have a clue what's wrong and there is no code. There is no problem with the MAF sensor or fuel pressure or fuel filter, fuel pump, spark plugs, coil pack, etc. I have been told that it is a water temp sensor problem but I don't know how to resolve it,

God Bless

 

[tobyduck]

Thanks!

 

[Earl43P]

Could be the fuel pressure bleeding off.

Turn the key to Run (2 sec), then Off to prime the fuel pump a few times before a cold start, see if that helps.

 

[adsm08]

Could be the fuel pressure bleeding off.

Turn the key to Run (2 sec), then Off to prime the fuel pump a few times before a cold start, see if that helps.

No, it couldn't. Fuel pressure can bleed off, but it wouldn't cause the OP's symptom. It will cause a hard start and long crank, but usually giving it some pedal doesn't help much and it will idle fine once it gets going.

I'm with Jim and whoever told him it was a ECT sensor issue. It sounds like the sensor has gone bad and is always sending a warm signal. That WILL make it idle like that until it actually gets to the lowest temp the sensor will send an accurate signal for, at which point it will start running properly again.